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000
FXUS64 KFWD 262327
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
527 PM CST THU FEB 26 2015

.AVIATION...
THE AFTERNOON DISCUSSION EXPLAINS THE SYNOPTIC SITUATION MUCH
BETTER THAN I CAN. AS FAR AS AVIATION GOES...TIMING THE ONSET OF
SNOW IS TRICKY BECAUSE OF THE NEED TO SATURATE THE LOWER
ATMOSPHERE BEFORE SNOW CAN HIT THE GROUND. CURRENT GUIDANCE STILL
SUGGESTS AROUND 17Z AND WILL STICK WITH THAT FOR NOW. BY FRIDAY
EVENING...ATMOSPHERE DRIES OUT FROM THE TOP DOWN...AND MOISTURE
EXITS THE DENDRITIC ZONE AROUND 03Z SATURDAY WHICH IS WHERE I
SWITCHED THE DFW TAF TO -FZDZ WITH SOME GRAINY SNOW POSSIBLY
MIXED IN. AT ANY RATE... -FZDZ SHOULD CONTINUE AT LEAST
INTERMITTENTLY THROUGH SATURDAY MORNING WHEN SURFACE TEMPS CLIMB
ABOVE FREEZING.

WACO IS FAR ENOUGH SOUTH THAT THEY MAY MISS OUT ON ALL THE WINTER
FUN...AND HAVE LEFT THEIR TAF DRY. SATURDAY MORNING MAY BRING
DRIZZLE...BUT TEMPS WILL BE ABOVE FREEZING. 84

&&

.PREV DISCUSSION... /ISSUED 401 PM CST THU FEB 26 2015/
...WINTER WEATHER ADVISORY ISSUED FOR THE NORTHWEST HALF OF THE
CWA INCLUDING THE DFW METROPLEX...

SNOW BAND FORCED VIA FRONTOGENESIS FINALLY WANED EARLY THIS
AFTERNOON WITH HIGHEST SNOW TOTALS OF 1-2 INCHES FROM YOUNG COUNTY
INTO PALO PINTO COUNTY. WHILE TEMPS ARE NEAR OR BELOW FREEZING IN
THIS AREA...SHERIFF OFFICES REPORT THAT SNOW HAS BEEN STEADILY
CLEARING OFF OF THE ROAD...LIKELY SUBLIMING AS DRY NORTH WINDS
BRING DEWPOINTS DOWN INTO THE TEENS OVER THE REGION. THE COLD AND
DRY ADVECTION WILL CONTINUE INTO THE OVERNIGHT HOURS AND WILL HELP
TEMPS FALL INTO THE 20S AREAWIDE DESPITE EXTENSIVE CLOUD COVER.

TEXAS REMAINS AT THE BASE OF A BROAD LONGWAVE TROUGH OVER THE
COUNTRY AND AS A RESULT ARCTIC AIR WILL CONTINUE TO POUR SOUTHWARD
THROUGH THE PLAINS WITH OUR THERMAL PROFILE BECOMING UNUSUALLY
COLD ALOFT. MEANWHILE A FAST MOVING SHORTWAVE THAT IS CURRENTLY
LOCATED NEAR THE FOUR CORNERS REGION WILL TRACK THROUGH THE REGION
TOMORROW. FOR AN OPEN SHORTWAVE TROUGH...IT HAS AN IMPRESSIVE
APPEARANCE ON TODAYS WATER VAPOR LOOP AND IT CERTAINLY RAISES
CONFIDENCE THAT STRONG LIFT WILL OVERSPREAD NORTH TEXAS BY
DAYBREAK. THERMAL PROFILES WILL BE VERY COLD AND THERE IS NO
QUESTION THAT PRECIPITATION WILL BE IN THE FORM OF SNOW. IN FACT
THE ONLY CONCERN OR MITIGATING FACTOR WITH SNOW IS GOING TO BE
VERY DRY AIR IN THE LOWER LEVELS. CLIMATOLOGY OF SNOW PATTERNS
SAYS THESE SYSTEMS OFTEN NEVER PRODUCE MORE THAN 4 INCHES OF SNOW
BECAUSE THEY ARE UNABLE TO GRAB ANY QUALITY LOW LEVEL MOISTURE
FROM THE GULF SINCE THE 850MB WINDS NEVER GET AN OPPORTUNITY TO
TURN TO THE SOUTH. THUS THE SNOW THAT IS PRODUCED ALOFT WILL HAVE
TO WORK THROUGH AND SATURATE THE DRY LAYER BEFORE IT CAN REACH THE
GROUND. HOW MUCH SNOW THIS DRY LAYER WILL EAT UP IS A ESSENTIALLY
AN UNANSWERABLE QUESTION...BUT IT IS A BIG LIMITING FACTOR.

DESPITE THE MOISTURE CONCERN...I DONT WANT TO IMPLY THAT I AM NOT
IMPRESSED AT THE SETUP AT HAND. THIS SYSTEM WILL HAVE VERY COLD
AIR IN PLACE WITH SATURATION FROM -10C TO -20C WHICH IS THE
FAVORABLE ZONE FOR SNOW DENDRITES...AND WILL HELP MAKE SNOW
FLAKES GROW FAST AND LARGE. IN ADDITION...STEEP LAPSE RATES OF 6
TO 7 DEG/KM EXIST FROM 400-600MB WHICH ADDS AN ELEMENT OF
CONVECTIVE INSTABILITY AND EXTRA VERTICAL DEPTH FOR SNOW TO GROW.
GIVEN THE COLD TEMPS IN PLACE AND FAVORABLE SNOW MAKING
MICROPHYSICS ENVIRONMENT...AN UNUSUALLY HIGH SNOWFALL TO LIQUID
WATER RATIO IS EXPECTED. THIS SNOW WILL NOT BE HEAVY AND WET LIKE
YESTERDAY...BUT MORE DRY AND FLUFFY.

SINCE THE SNOW IS DRIVEN BY UPWARD DYNAMIC FORCING...THE TRACK OF
THE SHORTWAVE WILL DETERMINE WHERE THE SNOW FALLS. BECAUSE THIS
SYSTEM PIVOTS THROUGH THE NORTHWEST HALF OF THE REGION...THIS IS
THE AREA THAT ACCUMULATING SNOW IS MOST LIKELY. AN ADVISORY WAS
ISSUED ALONG AND NORTHWEST OF A LINE FROM COMANCHE TO DALLAS TO
COOPER. FOR THE NORTHWESTERN PART OF THE ADVISORY...NORTHWEST OF A
EASTLAND TO GAINESVILLE LINE...HAVE GONE 2 TO 4 INCHES OF SNOW
WHICH IS ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE. AS YOU HEAD
FARTHER SOUTHEAST ACROSS THE CWA...SNOW AMOUNTS WILL TAPER OFF TO
JUST A DUSTING. FOR THE METROPLEX THE CURRENT FORECAST IS FOR 0.5
TO 1.5 INCHES WITH THE LOWER AMOUNTS BEING IN SOUTHEAST DALLAS
COUNTY. I MUST STRESS THAT JUST AN ERROR OF 0.1 INCHES OF LIQUID
QPF MAY BALLOON OUT TO AN EXTRA 2 INCHES OF SNOWFALL OR RESULT IN
WAY LESS THAN FORECAST TOO.

HIGH TEMPERATURES TOMORROW WILL BE BELOW FREEZING FOR THE ENTIRE
AREA...BUT IN AREAS WHERE SNOW FALLS...TEMPS WILL LIKELY DROP
INTO THE 20S. THIS MEANS WE DONT EXPECT A LOT OF MELTING WHEN IT
HITS THE GROUND OR STREETS. IT IS REALLY HARD TO KNOW IF TRAVEL
IMPACTS WILL BEGIN AT A HALF INCH OR 1 INCH OR 2 INCHES. THERE IS
THE POTENTIAL OF TRAVEL IMPACTS ON BRIDGES AND OVERPASSES IN THE
METROPLEX AT EVEN A HALF INCH...WHICH IS WHY WE FELT IT WAS BEST
TO INCLUDE THEM IN THE ADVISORY FOR A SEEMINGLY LOW AMOUNT OF
SNOW...THAT PLUS THE INHERENT UNCERTAINTIES IN FORECASTING SNOW
AMOUNTS IN THE FIRST PLACE! IF THE BAND OF SNOW DOES TRACK TOO
FAR NORTHWEST TO AFFECT THE METROPLEX...THE WINTER EVENT
CONTINUES INTO FRIDAY NIGHT AND SATURDAY SO IT WOULD JUST SERVE
AS EXTRA LEAD TIME FOR THAT.

AFTER THE SHORTWAVE PASSES FRIDAY AFTERNOON...WINDS JUST ABOVE THE
SURFACE BECOME MORE SOUTHEASTERLY IN RESPONSE TO A DIGGING TROUGH
ON THE WEST COAST. THESE WINDS WILL START A STRONG WARM/MOIST
ADVECTION PATTERN WITH ISENTROPIC LIFT ORGANIZING OVER THE ENTIRE
REGION. THIS LIFT WILL BE SUSTAINED FROM FRIDAY NIGHT THROUGH
SUNDAY...WITH DRIZZLE AND LIGHT SHOWERS LIKELY ACROSS NORTH TEXAS.
MOS POPS LOOK MUCH TOO LOW GIVEN THE STRENGTH AND PERSISTENCE OF
THIS SIGNAL. THE ISSUE IS THAT TEMPERATURES WILL STILL BE BELOW
FREEZING AT THE SURFACE INTO SATURDAY. AND WHILE THE ENTIRE COLUMN
IS BELOW FREEZING FRIDAY NIGHT...THE PRECIPITATION TYPE COULD
SWITCH FROM LIGHT SNOW GRAINS TO FREEZING DRIZZLE. FROZEN
PRECIPITATION REQUIRES AN ICE NUCLEI BECAUSE WATER DOES NOT KNOW
HOW TO FORM INTO THE CRYSTAL STRUCTURE WITHOUT HELP. PURE WATER
DOES NOT FREEZE UNTIL -40C...BUT IN REAL WORLD CLOUDS...POLLEN AND
DIRT PARTICLES WILL /TEACH/ WATER HOW TO FREEZE AT TEMPS OF -8C.
SO ONCE TEMPERATURES IN THE CLOUD RISE ABOVE -8C BUT STAY BELOW
FREEZING...THERE WILL NO LONGER BE ICE IN THE CLOUD...AND
PRECIPITATION WILL BE SUPER COOLED RAINDROPS WHICH FREEZE ON
CONTACT WITH THE SURFACE. THIS TYPE OF FREEZING RAIN/DRIZZLE IS OF
THE HIGHEST IMPACT BECAUSE IT IS SO EFFICIENT AT GOING TO ICE
WHEN IT HITS THE SURFACE. AS A RESULT WE ARE CONCERNED THAT
BRIDGES AND OVERPASSES WILL RECEIVE A GLAZE OF ICE FRIDAY NIGHT
INTO SATURDAY. UNTIL TEMPS RISE ABOVE FREEZING SATURDAY
AFTERNOON...THIS WILL BE A BIG CONCERN FOR TRAVEL. WE EXPECT MOST
OF THE CWA...WITH PERHAPS THE EXCEPTION OF THE SOUTHEAST ZONES TO
CONTEND WITH THIS FREEZING PRECIP. THE WINTER WEATHER ADVISORY
WILL LIKELY BE EXPANDED TO INCLUDE ADDITIONAL COUNTIES DURING THE
NEXT 24 HOURS.

ONCE TEMPS RISE ABOVE FREEZING SATURDAY NIGHT WITH THE APPROACH
AND PASSAGE OF A WARM FRONT...JUST A CHANCE OF RAIN SHOWERS ARE
EXPECTED SUNDAY. THE FRONT WILL SLOSH BACK TO THE SOUTH ON MONDAY
WITH COOLER TEMPS AGAIN...BUT THEY WILL REMAIN ABOVE FREEZING. THE
CHANCE OF SHOWERS NEAR AND BEHIND THE FRONT WILL PERSIST. ON
TUESDAY A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH THE PLAINS AND
BRING MUCH WARMER GULF AIR INTO THE REGION WITH HIGHS IN THE 70S.
THIS WILL RESULT IN SOME SURFACE INSTABILITY...AND PERHAPS A
SEVERE WEATHER THREAT WHEN THE NEXT FRONT MOVES THROUGH TUESDAY.
THE SW FLOW BEHIND THE FRONT MAY MEAN IT IS NOT UNTIL WEDNESDAY
THAT THE RAIN AND CLOUDS CAN BE CLEARED FROM THE FORECAST...BUT
EVENTUALLY DRIER WEATHER WILL PREVAIL BY MID-LATE WEEK.

TR.92

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  26  32  28  38  37 /   5  60  60  60  40
WACO, TX              28  35  30  40  39 /   5  20  40  60  40
PARIS, TX             23  30  26  38  37 /   5  50  60  60  40
DENTON, TX            24  30  26  36  35 /   5  70  60  60  40
MCKINNEY, TX          25  31  27  38  37 /   5  60  60  60  40
DALLAS, TX            26  32  29  39  38 /   5  60  50  60  40
TERRELL, TX           27  33  29  40  39 /   5  40  40  60  40
CORSICANA, TX         28  35  30  42  41 /   5  20  40  60  40
TEMPLE, TX            28  36  32  41  40 /   5  20  50  60  40
MINERAL WELLS, TX     25  29  26  35  34 /  10  70  60  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 PM CST SATURDAY
FOR TXZ091>095-100>106-115>120-129>133-141.


&&

$$

 /




000
FXUS64 KFWD 262327
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
527 PM CST THU FEB 26 2015

.AVIATION...
THE AFTERNOON DISCUSSION EXPLAINS THE SYNOPTIC SITUATION MUCH
BETTER THAN I CAN. AS FAR AS AVIATION GOES...TIMING THE ONSET OF
SNOW IS TRICKY BECAUSE OF THE NEED TO SATURATE THE LOWER
ATMOSPHERE BEFORE SNOW CAN HIT THE GROUND. CURRENT GUIDANCE STILL
SUGGESTS AROUND 17Z AND WILL STICK WITH THAT FOR NOW. BY FRIDAY
EVENING...ATMOSPHERE DRIES OUT FROM THE TOP DOWN...AND MOISTURE
EXITS THE DENDRITIC ZONE AROUND 03Z SATURDAY WHICH IS WHERE I
SWITCHED THE DFW TAF TO -FZDZ WITH SOME GRAINY SNOW POSSIBLY
MIXED IN. AT ANY RATE... -FZDZ SHOULD CONTINUE AT LEAST
INTERMITTENTLY THROUGH SATURDAY MORNING WHEN SURFACE TEMPS CLIMB
ABOVE FREEZING.

WACO IS FAR ENOUGH SOUTH THAT THEY MAY MISS OUT ON ALL THE WINTER
FUN...AND HAVE LEFT THEIR TAF DRY. SATURDAY MORNING MAY BRING
DRIZZLE...BUT TEMPS WILL BE ABOVE FREEZING. 84

&&

.PREV DISCUSSION... /ISSUED 401 PM CST THU FEB 26 2015/
...WINTER WEATHER ADVISORY ISSUED FOR THE NORTHWEST HALF OF THE
CWA INCLUDING THE DFW METROPLEX...

SNOW BAND FORCED VIA FRONTOGENESIS FINALLY WANED EARLY THIS
AFTERNOON WITH HIGHEST SNOW TOTALS OF 1-2 INCHES FROM YOUNG COUNTY
INTO PALO PINTO COUNTY. WHILE TEMPS ARE NEAR OR BELOW FREEZING IN
THIS AREA...SHERIFF OFFICES REPORT THAT SNOW HAS BEEN STEADILY
CLEARING OFF OF THE ROAD...LIKELY SUBLIMING AS DRY NORTH WINDS
BRING DEWPOINTS DOWN INTO THE TEENS OVER THE REGION. THE COLD AND
DRY ADVECTION WILL CONTINUE INTO THE OVERNIGHT HOURS AND WILL HELP
TEMPS FALL INTO THE 20S AREAWIDE DESPITE EXTENSIVE CLOUD COVER.

TEXAS REMAINS AT THE BASE OF A BROAD LONGWAVE TROUGH OVER THE
COUNTRY AND AS A RESULT ARCTIC AIR WILL CONTINUE TO POUR SOUTHWARD
THROUGH THE PLAINS WITH OUR THERMAL PROFILE BECOMING UNUSUALLY
COLD ALOFT. MEANWHILE A FAST MOVING SHORTWAVE THAT IS CURRENTLY
LOCATED NEAR THE FOUR CORNERS REGION WILL TRACK THROUGH THE REGION
TOMORROW. FOR AN OPEN SHORTWAVE TROUGH...IT HAS AN IMPRESSIVE
APPEARANCE ON TODAYS WATER VAPOR LOOP AND IT CERTAINLY RAISES
CONFIDENCE THAT STRONG LIFT WILL OVERSPREAD NORTH TEXAS BY
DAYBREAK. THERMAL PROFILES WILL BE VERY COLD AND THERE IS NO
QUESTION THAT PRECIPITATION WILL BE IN THE FORM OF SNOW. IN FACT
THE ONLY CONCERN OR MITIGATING FACTOR WITH SNOW IS GOING TO BE
VERY DRY AIR IN THE LOWER LEVELS. CLIMATOLOGY OF SNOW PATTERNS
SAYS THESE SYSTEMS OFTEN NEVER PRODUCE MORE THAN 4 INCHES OF SNOW
BECAUSE THEY ARE UNABLE TO GRAB ANY QUALITY LOW LEVEL MOISTURE
FROM THE GULF SINCE THE 850MB WINDS NEVER GET AN OPPORTUNITY TO
TURN TO THE SOUTH. THUS THE SNOW THAT IS PRODUCED ALOFT WILL HAVE
TO WORK THROUGH AND SATURATE THE DRY LAYER BEFORE IT CAN REACH THE
GROUND. HOW MUCH SNOW THIS DRY LAYER WILL EAT UP IS A ESSENTIALLY
AN UNANSWERABLE QUESTION...BUT IT IS A BIG LIMITING FACTOR.

DESPITE THE MOISTURE CONCERN...I DONT WANT TO IMPLY THAT I AM NOT
IMPRESSED AT THE SETUP AT HAND. THIS SYSTEM WILL HAVE VERY COLD
AIR IN PLACE WITH SATURATION FROM -10C TO -20C WHICH IS THE
FAVORABLE ZONE FOR SNOW DENDRITES...AND WILL HELP MAKE SNOW
FLAKES GROW FAST AND LARGE. IN ADDITION...STEEP LAPSE RATES OF 6
TO 7 DEG/KM EXIST FROM 400-600MB WHICH ADDS AN ELEMENT OF
CONVECTIVE INSTABILITY AND EXTRA VERTICAL DEPTH FOR SNOW TO GROW.
GIVEN THE COLD TEMPS IN PLACE AND FAVORABLE SNOW MAKING
MICROPHYSICS ENVIRONMENT...AN UNUSUALLY HIGH SNOWFALL TO LIQUID
WATER RATIO IS EXPECTED. THIS SNOW WILL NOT BE HEAVY AND WET LIKE
YESTERDAY...BUT MORE DRY AND FLUFFY.

SINCE THE SNOW IS DRIVEN BY UPWARD DYNAMIC FORCING...THE TRACK OF
THE SHORTWAVE WILL DETERMINE WHERE THE SNOW FALLS. BECAUSE THIS
SYSTEM PIVOTS THROUGH THE NORTHWEST HALF OF THE REGION...THIS IS
THE AREA THAT ACCUMULATING SNOW IS MOST LIKELY. AN ADVISORY WAS
ISSUED ALONG AND NORTHWEST OF A LINE FROM COMANCHE TO DALLAS TO
COOPER. FOR THE NORTHWESTERN PART OF THE ADVISORY...NORTHWEST OF A
EASTLAND TO GAINESVILLE LINE...HAVE GONE 2 TO 4 INCHES OF SNOW
WHICH IS ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE. AS YOU HEAD
FARTHER SOUTHEAST ACROSS THE CWA...SNOW AMOUNTS WILL TAPER OFF TO
JUST A DUSTING. FOR THE METROPLEX THE CURRENT FORECAST IS FOR 0.5
TO 1.5 INCHES WITH THE LOWER AMOUNTS BEING IN SOUTHEAST DALLAS
COUNTY. I MUST STRESS THAT JUST AN ERROR OF 0.1 INCHES OF LIQUID
QPF MAY BALLOON OUT TO AN EXTRA 2 INCHES OF SNOWFALL OR RESULT IN
WAY LESS THAN FORECAST TOO.

HIGH TEMPERATURES TOMORROW WILL BE BELOW FREEZING FOR THE ENTIRE
AREA...BUT IN AREAS WHERE SNOW FALLS...TEMPS WILL LIKELY DROP
INTO THE 20S. THIS MEANS WE DONT EXPECT A LOT OF MELTING WHEN IT
HITS THE GROUND OR STREETS. IT IS REALLY HARD TO KNOW IF TRAVEL
IMPACTS WILL BEGIN AT A HALF INCH OR 1 INCH OR 2 INCHES. THERE IS
THE POTENTIAL OF TRAVEL IMPACTS ON BRIDGES AND OVERPASSES IN THE
METROPLEX AT EVEN A HALF INCH...WHICH IS WHY WE FELT IT WAS BEST
TO INCLUDE THEM IN THE ADVISORY FOR A SEEMINGLY LOW AMOUNT OF
SNOW...THAT PLUS THE INHERENT UNCERTAINTIES IN FORECASTING SNOW
AMOUNTS IN THE FIRST PLACE! IF THE BAND OF SNOW DOES TRACK TOO
FAR NORTHWEST TO AFFECT THE METROPLEX...THE WINTER EVENT
CONTINUES INTO FRIDAY NIGHT AND SATURDAY SO IT WOULD JUST SERVE
AS EXTRA LEAD TIME FOR THAT.

AFTER THE SHORTWAVE PASSES FRIDAY AFTERNOON...WINDS JUST ABOVE THE
SURFACE BECOME MORE SOUTHEASTERLY IN RESPONSE TO A DIGGING TROUGH
ON THE WEST COAST. THESE WINDS WILL START A STRONG WARM/MOIST
ADVECTION PATTERN WITH ISENTROPIC LIFT ORGANIZING OVER THE ENTIRE
REGION. THIS LIFT WILL BE SUSTAINED FROM FRIDAY NIGHT THROUGH
SUNDAY...WITH DRIZZLE AND LIGHT SHOWERS LIKELY ACROSS NORTH TEXAS.
MOS POPS LOOK MUCH TOO LOW GIVEN THE STRENGTH AND PERSISTENCE OF
THIS SIGNAL. THE ISSUE IS THAT TEMPERATURES WILL STILL BE BELOW
FREEZING AT THE SURFACE INTO SATURDAY. AND WHILE THE ENTIRE COLUMN
IS BELOW FREEZING FRIDAY NIGHT...THE PRECIPITATION TYPE COULD
SWITCH FROM LIGHT SNOW GRAINS TO FREEZING DRIZZLE. FROZEN
PRECIPITATION REQUIRES AN ICE NUCLEI BECAUSE WATER DOES NOT KNOW
HOW TO FORM INTO THE CRYSTAL STRUCTURE WITHOUT HELP. PURE WATER
DOES NOT FREEZE UNTIL -40C...BUT IN REAL WORLD CLOUDS...POLLEN AND
DIRT PARTICLES WILL /TEACH/ WATER HOW TO FREEZE AT TEMPS OF -8C.
SO ONCE TEMPERATURES IN THE CLOUD RISE ABOVE -8C BUT STAY BELOW
FREEZING...THERE WILL NO LONGER BE ICE IN THE CLOUD...AND
PRECIPITATION WILL BE SUPER COOLED RAINDROPS WHICH FREEZE ON
CONTACT WITH THE SURFACE. THIS TYPE OF FREEZING RAIN/DRIZZLE IS OF
THE HIGHEST IMPACT BECAUSE IT IS SO EFFICIENT AT GOING TO ICE
WHEN IT HITS THE SURFACE. AS A RESULT WE ARE CONCERNED THAT
BRIDGES AND OVERPASSES WILL RECEIVE A GLAZE OF ICE FRIDAY NIGHT
INTO SATURDAY. UNTIL TEMPS RISE ABOVE FREEZING SATURDAY
AFTERNOON...THIS WILL BE A BIG CONCERN FOR TRAVEL. WE EXPECT MOST
OF THE CWA...WITH PERHAPS THE EXCEPTION OF THE SOUTHEAST ZONES TO
CONTEND WITH THIS FREEZING PRECIP. THE WINTER WEATHER ADVISORY
WILL LIKELY BE EXPANDED TO INCLUDE ADDITIONAL COUNTIES DURING THE
NEXT 24 HOURS.

ONCE TEMPS RISE ABOVE FREEZING SATURDAY NIGHT WITH THE APPROACH
AND PASSAGE OF A WARM FRONT...JUST A CHANCE OF RAIN SHOWERS ARE
EXPECTED SUNDAY. THE FRONT WILL SLOSH BACK TO THE SOUTH ON MONDAY
WITH COOLER TEMPS AGAIN...BUT THEY WILL REMAIN ABOVE FREEZING. THE
CHANCE OF SHOWERS NEAR AND BEHIND THE FRONT WILL PERSIST. ON
TUESDAY A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH THE PLAINS AND
BRING MUCH WARMER GULF AIR INTO THE REGION WITH HIGHS IN THE 70S.
THIS WILL RESULT IN SOME SURFACE INSTABILITY...AND PERHAPS A
SEVERE WEATHER THREAT WHEN THE NEXT FRONT MOVES THROUGH TUESDAY.
THE SW FLOW BEHIND THE FRONT MAY MEAN IT IS NOT UNTIL WEDNESDAY
THAT THE RAIN AND CLOUDS CAN BE CLEARED FROM THE FORECAST...BUT
EVENTUALLY DRIER WEATHER WILL PREVAIL BY MID-LATE WEEK.

TR.92

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  26  32  28  38  37 /   5  60  60  60  40
WACO, TX              28  35  30  40  39 /   5  20  40  60  40
PARIS, TX             23  30  26  38  37 /   5  50  60  60  40
DENTON, TX            24  30  26  36  35 /   5  70  60  60  40
MCKINNEY, TX          25  31  27  38  37 /   5  60  60  60  40
DALLAS, TX            26  32  29  39  38 /   5  60  50  60  40
TERRELL, TX           27  33  29  40  39 /   5  40  40  60  40
CORSICANA, TX         28  35  30  42  41 /   5  20  40  60  40
TEMPLE, TX            28  36  32  41  40 /   5  20  50  60  40
MINERAL WELLS, TX     25  29  26  35  34 /  10  70  60  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 PM CST SATURDAY
FOR TXZ091>095-100>106-115>120-129>133-141.


&&

$$

 /





000
FXUS64 KFWD 262201
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
401 PM CST THU FEB 26 2015

.DISCUSSION...
...WINTER WEATHER ADVISORY ISSUED FOR THE NORTHWEST HALF OF THE
CWA INCLUDING THE DFW METROPLEX...

SNOW BAND FORCED VIA FRONTOGENESIS FINALLY WANED EARLY THIS
AFTERNOON WITH HIGHEST SNOW TOTALS OF 1-2 INCHES FROM YOUNG COUNTY
INTO PALO PINTO COUNTY. WHILE TEMPS ARE NEAR OR BELOW FREEZING IN
THIS AREA...SHERIFF OFFICES REPORT THAT SNOW HAS BEEN STEADILY
CLEARING OFF OF THE ROAD...LIKELY SUBLIMING AS DRY NORTH WINDS
BRING DEWPOINTS DOWN INTO THE TEENS OVER THE REGION. THE COLD AND
DRY ADVECTION WILL CONTINUE INTO THE OVERNIGHT HOURS AND WILL HELP
TEMPS FALL INTO THE 20S AREAWIDE DESPITE EXTENSIVE CLOUD COVER.

TEXAS REMAINS AT THE BASE OF A BROAD LONGWAVE TROUGH OVER THE
COUNTRY AND AS A RESULT ARCTIC AIR WILL CONTINUE TO POUR SOUTHWARD
THROUGH THE PLAINS WITH OUR THERMAL PROFILE BECOMING UNUSUALLY
COLD ALOFT. MEANWHILE A FAST MOVING SHORTWAVE THAT IS CURRENTLY
LOCATED NEAR THE FOUR CORNERS REGION WILL TRACK THROUGH THE REGION
TOMORROW. FOR AN OPEN SHORTWAVE TROUGH...IT HAS AN IMPRESSIVE
APPEARANCE ON TODAYS WATER VAPOR LOOP AND IT CERTAINLY RAISES
CONFIDENCE THAT STRONG LIFT WILL OVERSPREAD NORTH TEXAS BY
DAYBREAK. THERMAL PROFILES WILL BE VERY COLD AND THERE IS NO
QUESTION THAT PRECIPITATION WILL BE IN THE FORM OF SNOW. IN FACT
THE ONLY CONCERN OR MITIGATING FACTOR WITH SNOW IS GOING TO BE
VERY DRY AIR IN THE LOWER LEVELS. CLIMATOLOGY OF SNOW PATTERNS
SAYS THESE SYSTEMS OFTEN NEVER PRODUCE MORE THAN 4 INCHES OF SNOW
BECAUSE THEY ARE UNABLE TO GRAB ANY QUALITY LOW LEVEL MOISTURE
FROM THE GULF SINCE THE 850MB WINDS NEVER GET AN OPPORTUNITY TO
TURN TO THE SOUTH. THUS THE SNOW THAT IS PRODUCED ALOFT WILL HAVE
TO WORK THROUGH AND SATURATE THE DRY LAYER BEFORE IT CAN REACH THE
GROUND. HOW MUCH SNOW THIS DRY LAYER WILL EAT UP IS A ESSENTIALLY
AN UNANSWERABLE QUESTION...BUT IT IS A BIG LIMITING FACTOR.

DESPITE THE MOISTURE CONCERN...I DONT WANT TO IMPLY THAT I AM NOT
IMPRESSED AT THE SETUP AT HAND. THIS SYSTEM WILL HAVE VERY COLD
AIR IN PLACE WITH SATURATION FROM -10C TO -20C WHICH IS THE
FAVORABLE ZONE FOR SNOW DENDRITES...AND WILL HELP MAKE SNOW
FLAKES GROW FAST AND LARGE. IN ADDITION...STEEP LAPSE RATES OF 6
TO 7 DEG/KM EXIST FROM 400-600MB WHICH ADDS AN ELEMENT OF
CONVECTIVE INSTABILITY AND EXTRA VERTICAL DEPTH FOR SNOW TO GROW.
GIVEN THE COLD TEMPS IN PLACE AND FAVORABLE SNOW MAKING
MICROPHYSICS ENVIRONMENT...AN UNUSUALLY HIGH SNOWFALL TO LIQUID
WATER RATIO IS EXPECTED. THIS SNOW WILL NOT BE HEAVY AND WET LIKE
YESTERDAY...BUT MORE DRY AND FLUFFY.

SINCE THE SNOW IS DRIVEN BY UPWARD DYNAMIC FORCING...THE TRACK OF
THE SHORTWAVE WILL DETERMINE WHERE THE SNOW FALLS. BECAUSE THIS
SYSTEM PIVOTS THROUGH THE NORTHWEST HALF OF THE REGION...THIS IS
THE AREA THAT ACCUMULATING SNOW IS MOST LIKELY. AN ADVISORY WAS
ISSUED ALONG AND NORTHWEST OF A LINE FROM COMANCHE TO DALLAS TO
COOPER. FOR THE NORTHWESTERN PART OF THE ADVISORY...NORTHWEST OF A
EASTLAND TO GAINESVILLE LINE...HAVE GONE 2 TO 4 INCHES OF SNOW
WHICH IS ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE. AS YOU HEAD
FARTHER SOUTHEAST ACROSS THE CWA...SNOW AMOUNTS WILL TAPER OFF TO
JUST A DUSTING. FOR THE METROPLEX THE CURRENT FORECAST IS FOR 0.5
TO 1.5 INCHES WITH THE LOWER AMOUNTS BEING IN SOUTHEAST DALLAS
COUNTY. I MUST STRESS THAT JUST AN ERROR OF 0.1 INCHES OF LIQUID
QPF MAY BALLOON OUT TO AN EXTRA 2 INCHES OF SNOWFALL OR RESULT IN
WAY LESS THAN FORECAST TOO.

HIGH TEMPERATURES TOMORROW WILL BE BELOW FREEZING FOR THE ENTIRE
AREA...BUT IN AREAS WHERE SNOW FALLS...TEMPS WILL LIKELY DROP
INTO THE 20S. THIS MEANS WE DONT EXPECT A LOT OF MELTING WHEN IT
HITS THE GROUND OR STREETS. IT IS REALLY HARD TO KNOW IF TRAVEL
IMPACTS WILL BEGIN AT A HALF INCH OR 1 INCH OR 2 INCHES. THERE IS
THE POTENTIAL OF TRAVEL IMPACTS ON BRIDGES AND OVERPASSES IN THE
METROPLEX AT EVEN A HALF INCH...WHICH IS WHY WE FELT IT WAS BEST
TO INCLUDE THEM IN THE ADVISORY FOR A SEEMINGLY LOW AMOUNT OF
SNOW...THAT PLUS THE INHERENT UNCERTAINTIES IN FORECASTING SNOW
AMOUNTS IN THE FIRST PLACE! IF THE BAND OF SNOW DOES TRACK TOO
FAR NORTHWEST TO AFFECT THE METROPLEX...THE WINTER EVENT
CONTINUES INTO FRIDAY NIGHT AND SATURDAY SO IT WOULD JUST SERVE
AS EXTRA LEAD TIME FOR THAT.

AFTER THE SHORTWAVE PASSES FRIDAY AFTERNOON...WINDS JUST ABOVE THE
SURFACE BECOME MORE SOUTHEASTERLY IN RESPONSE TO A DIGGING TROUGH
ON THE WEST COAST. THESE WINDS WILL START A STRONG WARM/MOIST
ADVECTION PATTERN WITH ISENTROPIC LIFT ORGANIZING OVER THE ENTIRE
REGION. THIS LIFT WILL BE SUSTAINED FROM FRIDAY NIGHT THROUGH
SUNDAY...WITH DRIZZLE AND LIGHT SHOWERS LIKELY ACROSS NORTH TEXAS.
MOS POPS LOOK MUCH TOO LOW GIVEN THE STRENGTH AND PERSISTENCE OF
THIS SIGNAL. THE ISSUE IS THAT TEMPERATURES WILL STILL BE BELOW
FREEZING AT THE SURFACE INTO SATURDAY. AND WHILE THE ENTIRE COLUMN
IS BELOW FREEZING FRIDAY NIGHT...THE PRECIPITATION TYPE COULD
SWITCH FROM LIGHT SNOW GRAINS TO FREEZING DRIZZLE. FROZEN
PRECIPITATION REQUIRES AN ICE NUCLEI BECAUSE WATER DOES NOT KNOW
HOW TO FORM INTO THE CRYSTAL STRUCTURE WITHOUT HELP. PURE WATER
DOES NOT FREEZE UNTIL -40C...BUT IN REAL WORLD CLOUDS...POLLEN AND
DIRT PARTICLES WILL /TEACH/ WATER HOW TO FREEZE AT TEMPS OF -8C.
SO ONCE TEMPERATURES IN THE CLOUD RISE ABOVE -8C BUT STAY BELOW
FREEZING...THERE WILL NO LONGER BE ICE IN THE CLOUD...AND
PRECIPITATION WILL BE SUPER COOLED RAINDROPS WHICH FREEZE ON
CONTACT WITH THE SURFACE. THIS TYPE OF FREEZING RAIN/DRIZZLE IS OF
THE HIGHEST IMPACT BECAUSE IT IS SO EFFICIENT AT GOING TO ICE
WHEN IT HITS THE SURFACE. AS A RESULT WE ARE CONCERNED THAT
BRIDGES AND OVERPASSES WILL RECEIVE A GLAZE OF ICE FRIDAY NIGHT
INTO SATURDAY. UNTIL TEMPS RISE ABOVE FREEZING SATURDAY
AFTERNOON...THIS WILL BE A BIG CONCERN FOR TRAVEL. WE EXPECT MOST
OF THE CWA...WITH PERHAPS THE EXCEPTION OF THE SOUTHEAST ZONES TO
CONTEND WITH THIS FREEZING PRECIP. THE WINTER WEATHER ADVISORY
WILL LIKELY BE EXPANDED TO INCLUDE ADDITIONAL COUNTIES DURING THE
NEXT 24 HOURS.

ONCE TEMPS RISE ABOVE FREEZING SATURDAY NIGHT WITH THE APPROACH
AND PASSAGE OF A WARM FRONT...JUST A CHANCE OF RAIN SHOWERS ARE
EXPECTED SUNDAY. THE FRONT WILL SLOSH BACK TO THE SOUTH ON MONDAY
WITH COOLER TEMPS AGAIN...BUT THEY WILL REMAIN ABOVE FREEZING. THE
CHANCE OF SHOWERS NEAR AND BEHIND THE FRONT WILL PERSIST. ON
TUESDAY A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH THE PLAINS AND
BRING MUCH WARMER GULF AIR INTO THE REGION WITH HIGHS IN THE 70S.
THIS WILL RESULT IN SOME SURFACE INSTABILITY...AND PERHAPS A
SEVERE WEATHER THREAT WHEN THE NEXT FRONT MOVES THROUGH TUESDAY.
THE SW FLOW BEHIND THE FRONT MAY MEAN IT IS NOT UNTIL WEDNESDAY
THAT THE RAIN AND CLOUDS CAN BE CLEARED FROM THE FORECAST...BUT
EVENTUALLY DRIER WEATHER WILL PREVAIL BY MID-LATE WEEK.

TR.92

&&

.AVIATION...
/ISSUED 1135 AM CST THU FEB 26 2015/

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  26  32  28  38  37 /   5  60  60  60  40
WACO, TX              28  35  30  40  39 /   5  20  40  60  40
PARIS, TX             23  30  26  38  37 /   5  50  60  60  40
DENTON, TX            24  30  26  36  35 /   5  70  60  60  40
MCKINNEY, TX          25  31  27  38  37 /   5  60  60  60  40
DALLAS, TX            26  32  29  39  38 /   5  60  50  60  40
TERRELL, TX           27  33  29  40  39 /   5  40  40  60  40
CORSICANA, TX         28  35  30  42  41 /   5  20  40  60  40
TEMPLE, TX            28  36  32  41  40 /   5  20  50  60  40
MINERAL WELLS, TX     25  29  26  35  34 /  10  70  60  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 PM CST SATURDAY
FOR TXZ091>095-100>106-115>120-129>133-141.


&&

$$

 /




000
FXUS64 KFWD 262201
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
401 PM CST THU FEB 26 2015

.DISCUSSION...
...WINTER WEATHER ADVISORY ISSUED FOR THE NORTHWEST HALF OF THE
CWA INCLUDING THE DFW METROPLEX...

SNOW BAND FORCED VIA FRONTOGENESIS FINALLY WANED EARLY THIS
AFTERNOON WITH HIGHEST SNOW TOTALS OF 1-2 INCHES FROM YOUNG COUNTY
INTO PALO PINTO COUNTY. WHILE TEMPS ARE NEAR OR BELOW FREEZING IN
THIS AREA...SHERIFF OFFICES REPORT THAT SNOW HAS BEEN STEADILY
CLEARING OFF OF THE ROAD...LIKELY SUBLIMING AS DRY NORTH WINDS
BRING DEWPOINTS DOWN INTO THE TEENS OVER THE REGION. THE COLD AND
DRY ADVECTION WILL CONTINUE INTO THE OVERNIGHT HOURS AND WILL HELP
TEMPS FALL INTO THE 20S AREAWIDE DESPITE EXTENSIVE CLOUD COVER.

TEXAS REMAINS AT THE BASE OF A BROAD LONGWAVE TROUGH OVER THE
COUNTRY AND AS A RESULT ARCTIC AIR WILL CONTINUE TO POUR SOUTHWARD
THROUGH THE PLAINS WITH OUR THERMAL PROFILE BECOMING UNUSUALLY
COLD ALOFT. MEANWHILE A FAST MOVING SHORTWAVE THAT IS CURRENTLY
LOCATED NEAR THE FOUR CORNERS REGION WILL TRACK THROUGH THE REGION
TOMORROW. FOR AN OPEN SHORTWAVE TROUGH...IT HAS AN IMPRESSIVE
APPEARANCE ON TODAYS WATER VAPOR LOOP AND IT CERTAINLY RAISES
CONFIDENCE THAT STRONG LIFT WILL OVERSPREAD NORTH TEXAS BY
DAYBREAK. THERMAL PROFILES WILL BE VERY COLD AND THERE IS NO
QUESTION THAT PRECIPITATION WILL BE IN THE FORM OF SNOW. IN FACT
THE ONLY CONCERN OR MITIGATING FACTOR WITH SNOW IS GOING TO BE
VERY DRY AIR IN THE LOWER LEVELS. CLIMATOLOGY OF SNOW PATTERNS
SAYS THESE SYSTEMS OFTEN NEVER PRODUCE MORE THAN 4 INCHES OF SNOW
BECAUSE THEY ARE UNABLE TO GRAB ANY QUALITY LOW LEVEL MOISTURE
FROM THE GULF SINCE THE 850MB WINDS NEVER GET AN OPPORTUNITY TO
TURN TO THE SOUTH. THUS THE SNOW THAT IS PRODUCED ALOFT WILL HAVE
TO WORK THROUGH AND SATURATE THE DRY LAYER BEFORE IT CAN REACH THE
GROUND. HOW MUCH SNOW THIS DRY LAYER WILL EAT UP IS A ESSENTIALLY
AN UNANSWERABLE QUESTION...BUT IT IS A BIG LIMITING FACTOR.

DESPITE THE MOISTURE CONCERN...I DONT WANT TO IMPLY THAT I AM NOT
IMPRESSED AT THE SETUP AT HAND. THIS SYSTEM WILL HAVE VERY COLD
AIR IN PLACE WITH SATURATION FROM -10C TO -20C WHICH IS THE
FAVORABLE ZONE FOR SNOW DENDRITES...AND WILL HELP MAKE SNOW
FLAKES GROW FAST AND LARGE. IN ADDITION...STEEP LAPSE RATES OF 6
TO 7 DEG/KM EXIST FROM 400-600MB WHICH ADDS AN ELEMENT OF
CONVECTIVE INSTABILITY AND EXTRA VERTICAL DEPTH FOR SNOW TO GROW.
GIVEN THE COLD TEMPS IN PLACE AND FAVORABLE SNOW MAKING
MICROPHYSICS ENVIRONMENT...AN UNUSUALLY HIGH SNOWFALL TO LIQUID
WATER RATIO IS EXPECTED. THIS SNOW WILL NOT BE HEAVY AND WET LIKE
YESTERDAY...BUT MORE DRY AND FLUFFY.

SINCE THE SNOW IS DRIVEN BY UPWARD DYNAMIC FORCING...THE TRACK OF
THE SHORTWAVE WILL DETERMINE WHERE THE SNOW FALLS. BECAUSE THIS
SYSTEM PIVOTS THROUGH THE NORTHWEST HALF OF THE REGION...THIS IS
THE AREA THAT ACCUMULATING SNOW IS MOST LIKELY. AN ADVISORY WAS
ISSUED ALONG AND NORTHWEST OF A LINE FROM COMANCHE TO DALLAS TO
COOPER. FOR THE NORTHWESTERN PART OF THE ADVISORY...NORTHWEST OF A
EASTLAND TO GAINESVILLE LINE...HAVE GONE 2 TO 4 INCHES OF SNOW
WHICH IS ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE. AS YOU HEAD
FARTHER SOUTHEAST ACROSS THE CWA...SNOW AMOUNTS WILL TAPER OFF TO
JUST A DUSTING. FOR THE METROPLEX THE CURRENT FORECAST IS FOR 0.5
TO 1.5 INCHES WITH THE LOWER AMOUNTS BEING IN SOUTHEAST DALLAS
COUNTY. I MUST STRESS THAT JUST AN ERROR OF 0.1 INCHES OF LIQUID
QPF MAY BALLOON OUT TO AN EXTRA 2 INCHES OF SNOWFALL OR RESULT IN
WAY LESS THAN FORECAST TOO.

HIGH TEMPERATURES TOMORROW WILL BE BELOW FREEZING FOR THE ENTIRE
AREA...BUT IN AREAS WHERE SNOW FALLS...TEMPS WILL LIKELY DROP
INTO THE 20S. THIS MEANS WE DONT EXPECT A LOT OF MELTING WHEN IT
HITS THE GROUND OR STREETS. IT IS REALLY HARD TO KNOW IF TRAVEL
IMPACTS WILL BEGIN AT A HALF INCH OR 1 INCH OR 2 INCHES. THERE IS
THE POTENTIAL OF TRAVEL IMPACTS ON BRIDGES AND OVERPASSES IN THE
METROPLEX AT EVEN A HALF INCH...WHICH IS WHY WE FELT IT WAS BEST
TO INCLUDE THEM IN THE ADVISORY FOR A SEEMINGLY LOW AMOUNT OF
SNOW...THAT PLUS THE INHERENT UNCERTAINTIES IN FORECASTING SNOW
AMOUNTS IN THE FIRST PLACE! IF THE BAND OF SNOW DOES TRACK TOO
FAR NORTHWEST TO AFFECT THE METROPLEX...THE WINTER EVENT
CONTINUES INTO FRIDAY NIGHT AND SATURDAY SO IT WOULD JUST SERVE
AS EXTRA LEAD TIME FOR THAT.

AFTER THE SHORTWAVE PASSES FRIDAY AFTERNOON...WINDS JUST ABOVE THE
SURFACE BECOME MORE SOUTHEASTERLY IN RESPONSE TO A DIGGING TROUGH
ON THE WEST COAST. THESE WINDS WILL START A STRONG WARM/MOIST
ADVECTION PATTERN WITH ISENTROPIC LIFT ORGANIZING OVER THE ENTIRE
REGION. THIS LIFT WILL BE SUSTAINED FROM FRIDAY NIGHT THROUGH
SUNDAY...WITH DRIZZLE AND LIGHT SHOWERS LIKELY ACROSS NORTH TEXAS.
MOS POPS LOOK MUCH TOO LOW GIVEN THE STRENGTH AND PERSISTENCE OF
THIS SIGNAL. THE ISSUE IS THAT TEMPERATURES WILL STILL BE BELOW
FREEZING AT THE SURFACE INTO SATURDAY. AND WHILE THE ENTIRE COLUMN
IS BELOW FREEZING FRIDAY NIGHT...THE PRECIPITATION TYPE COULD
SWITCH FROM LIGHT SNOW GRAINS TO FREEZING DRIZZLE. FROZEN
PRECIPITATION REQUIRES AN ICE NUCLEI BECAUSE WATER DOES NOT KNOW
HOW TO FORM INTO THE CRYSTAL STRUCTURE WITHOUT HELP. PURE WATER
DOES NOT FREEZE UNTIL -40C...BUT IN REAL WORLD CLOUDS...POLLEN AND
DIRT PARTICLES WILL /TEACH/ WATER HOW TO FREEZE AT TEMPS OF -8C.
SO ONCE TEMPERATURES IN THE CLOUD RISE ABOVE -8C BUT STAY BELOW
FREEZING...THERE WILL NO LONGER BE ICE IN THE CLOUD...AND
PRECIPITATION WILL BE SUPER COOLED RAINDROPS WHICH FREEZE ON
CONTACT WITH THE SURFACE. THIS TYPE OF FREEZING RAIN/DRIZZLE IS OF
THE HIGHEST IMPACT BECAUSE IT IS SO EFFICIENT AT GOING TO ICE
WHEN IT HITS THE SURFACE. AS A RESULT WE ARE CONCERNED THAT
BRIDGES AND OVERPASSES WILL RECEIVE A GLAZE OF ICE FRIDAY NIGHT
INTO SATURDAY. UNTIL TEMPS RISE ABOVE FREEZING SATURDAY
AFTERNOON...THIS WILL BE A BIG CONCERN FOR TRAVEL. WE EXPECT MOST
OF THE CWA...WITH PERHAPS THE EXCEPTION OF THE SOUTHEAST ZONES TO
CONTEND WITH THIS FREEZING PRECIP. THE WINTER WEATHER ADVISORY
WILL LIKELY BE EXPANDED TO INCLUDE ADDITIONAL COUNTIES DURING THE
NEXT 24 HOURS.

ONCE TEMPS RISE ABOVE FREEZING SATURDAY NIGHT WITH THE APPROACH
AND PASSAGE OF A WARM FRONT...JUST A CHANCE OF RAIN SHOWERS ARE
EXPECTED SUNDAY. THE FRONT WILL SLOSH BACK TO THE SOUTH ON MONDAY
WITH COOLER TEMPS AGAIN...BUT THEY WILL REMAIN ABOVE FREEZING. THE
CHANCE OF SHOWERS NEAR AND BEHIND THE FRONT WILL PERSIST. ON
TUESDAY A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH THE PLAINS AND
BRING MUCH WARMER GULF AIR INTO THE REGION WITH HIGHS IN THE 70S.
THIS WILL RESULT IN SOME SURFACE INSTABILITY...AND PERHAPS A
SEVERE WEATHER THREAT WHEN THE NEXT FRONT MOVES THROUGH TUESDAY.
THE SW FLOW BEHIND THE FRONT MAY MEAN IT IS NOT UNTIL WEDNESDAY
THAT THE RAIN AND CLOUDS CAN BE CLEARED FROM THE FORECAST...BUT
EVENTUALLY DRIER WEATHER WILL PREVAIL BY MID-LATE WEEK.

TR.92

&&

.AVIATION...
/ISSUED 1135 AM CST THU FEB 26 2015/

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  26  32  28  38  37 /   5  60  60  60  40
WACO, TX              28  35  30  40  39 /   5  20  40  60  40
PARIS, TX             23  30  26  38  37 /   5  50  60  60  40
DENTON, TX            24  30  26  36  35 /   5  70  60  60  40
MCKINNEY, TX          25  31  27  38  37 /   5  60  60  60  40
DALLAS, TX            26  32  29  39  38 /   5  60  50  60  40
TERRELL, TX           27  33  29  40  39 /   5  40  40  60  40
CORSICANA, TX         28  35  30  42  41 /   5  20  40  60  40
TEMPLE, TX            28  36  32  41  40 /   5  20  50  60  40
MINERAL WELLS, TX     25  29  26  35  34 /  10  70  60  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 PM CST SATURDAY
FOR TXZ091>095-100>106-115>120-129>133-141.


&&

$$

 /




000
FXUS64 KFWD 262201
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
401 PM CST THU FEB 26 2015

.DISCUSSION...
...WINTER WEATHER ADVISORY ISSUED FOR THE NORTHWEST HALF OF THE
CWA INCLUDING THE DFW METROPLEX...

SNOW BAND FORCED VIA FRONTOGENESIS FINALLY WANED EARLY THIS
AFTERNOON WITH HIGHEST SNOW TOTALS OF 1-2 INCHES FROM YOUNG COUNTY
INTO PALO PINTO COUNTY. WHILE TEMPS ARE NEAR OR BELOW FREEZING IN
THIS AREA...SHERIFF OFFICES REPORT THAT SNOW HAS BEEN STEADILY
CLEARING OFF OF THE ROAD...LIKELY SUBLIMING AS DRY NORTH WINDS
BRING DEWPOINTS DOWN INTO THE TEENS OVER THE REGION. THE COLD AND
DRY ADVECTION WILL CONTINUE INTO THE OVERNIGHT HOURS AND WILL HELP
TEMPS FALL INTO THE 20S AREAWIDE DESPITE EXTENSIVE CLOUD COVER.

TEXAS REMAINS AT THE BASE OF A BROAD LONGWAVE TROUGH OVER THE
COUNTRY AND AS A RESULT ARCTIC AIR WILL CONTINUE TO POUR SOUTHWARD
THROUGH THE PLAINS WITH OUR THERMAL PROFILE BECOMING UNUSUALLY
COLD ALOFT. MEANWHILE A FAST MOVING SHORTWAVE THAT IS CURRENTLY
LOCATED NEAR THE FOUR CORNERS REGION WILL TRACK THROUGH THE REGION
TOMORROW. FOR AN OPEN SHORTWAVE TROUGH...IT HAS AN IMPRESSIVE
APPEARANCE ON TODAYS WATER VAPOR LOOP AND IT CERTAINLY RAISES
CONFIDENCE THAT STRONG LIFT WILL OVERSPREAD NORTH TEXAS BY
DAYBREAK. THERMAL PROFILES WILL BE VERY COLD AND THERE IS NO
QUESTION THAT PRECIPITATION WILL BE IN THE FORM OF SNOW. IN FACT
THE ONLY CONCERN OR MITIGATING FACTOR WITH SNOW IS GOING TO BE
VERY DRY AIR IN THE LOWER LEVELS. CLIMATOLOGY OF SNOW PATTERNS
SAYS THESE SYSTEMS OFTEN NEVER PRODUCE MORE THAN 4 INCHES OF SNOW
BECAUSE THEY ARE UNABLE TO GRAB ANY QUALITY LOW LEVEL MOISTURE
FROM THE GULF SINCE THE 850MB WINDS NEVER GET AN OPPORTUNITY TO
TURN TO THE SOUTH. THUS THE SNOW THAT IS PRODUCED ALOFT WILL HAVE
TO WORK THROUGH AND SATURATE THE DRY LAYER BEFORE IT CAN REACH THE
GROUND. HOW MUCH SNOW THIS DRY LAYER WILL EAT UP IS A ESSENTIALLY
AN UNANSWERABLE QUESTION...BUT IT IS A BIG LIMITING FACTOR.

DESPITE THE MOISTURE CONCERN...I DONT WANT TO IMPLY THAT I AM NOT
IMPRESSED AT THE SETUP AT HAND. THIS SYSTEM WILL HAVE VERY COLD
AIR IN PLACE WITH SATURATION FROM -10C TO -20C WHICH IS THE
FAVORABLE ZONE FOR SNOW DENDRITES...AND WILL HELP MAKE SNOW
FLAKES GROW FAST AND LARGE. IN ADDITION...STEEP LAPSE RATES OF 6
TO 7 DEG/KM EXIST FROM 400-600MB WHICH ADDS AN ELEMENT OF
CONVECTIVE INSTABILITY AND EXTRA VERTICAL DEPTH FOR SNOW TO GROW.
GIVEN THE COLD TEMPS IN PLACE AND FAVORABLE SNOW MAKING
MICROPHYSICS ENVIRONMENT...AN UNUSUALLY HIGH SNOWFALL TO LIQUID
WATER RATIO IS EXPECTED. THIS SNOW WILL NOT BE HEAVY AND WET LIKE
YESTERDAY...BUT MORE DRY AND FLUFFY.

SINCE THE SNOW IS DRIVEN BY UPWARD DYNAMIC FORCING...THE TRACK OF
THE SHORTWAVE WILL DETERMINE WHERE THE SNOW FALLS. BECAUSE THIS
SYSTEM PIVOTS THROUGH THE NORTHWEST HALF OF THE REGION...THIS IS
THE AREA THAT ACCUMULATING SNOW IS MOST LIKELY. AN ADVISORY WAS
ISSUED ALONG AND NORTHWEST OF A LINE FROM COMANCHE TO DALLAS TO
COOPER. FOR THE NORTHWESTERN PART OF THE ADVISORY...NORTHWEST OF A
EASTLAND TO GAINESVILLE LINE...HAVE GONE 2 TO 4 INCHES OF SNOW
WHICH IS ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE. AS YOU HEAD
FARTHER SOUTHEAST ACROSS THE CWA...SNOW AMOUNTS WILL TAPER OFF TO
JUST A DUSTING. FOR THE METROPLEX THE CURRENT FORECAST IS FOR 0.5
TO 1.5 INCHES WITH THE LOWER AMOUNTS BEING IN SOUTHEAST DALLAS
COUNTY. I MUST STRESS THAT JUST AN ERROR OF 0.1 INCHES OF LIQUID
QPF MAY BALLOON OUT TO AN EXTRA 2 INCHES OF SNOWFALL OR RESULT IN
WAY LESS THAN FORECAST TOO.

HIGH TEMPERATURES TOMORROW WILL BE BELOW FREEZING FOR THE ENTIRE
AREA...BUT IN AREAS WHERE SNOW FALLS...TEMPS WILL LIKELY DROP
INTO THE 20S. THIS MEANS WE DONT EXPECT A LOT OF MELTING WHEN IT
HITS THE GROUND OR STREETS. IT IS REALLY HARD TO KNOW IF TRAVEL
IMPACTS WILL BEGIN AT A HALF INCH OR 1 INCH OR 2 INCHES. THERE IS
THE POTENTIAL OF TRAVEL IMPACTS ON BRIDGES AND OVERPASSES IN THE
METROPLEX AT EVEN A HALF INCH...WHICH IS WHY WE FELT IT WAS BEST
TO INCLUDE THEM IN THE ADVISORY FOR A SEEMINGLY LOW AMOUNT OF
SNOW...THAT PLUS THE INHERENT UNCERTAINTIES IN FORECASTING SNOW
AMOUNTS IN THE FIRST PLACE! IF THE BAND OF SNOW DOES TRACK TOO
FAR NORTHWEST TO AFFECT THE METROPLEX...THE WINTER EVENT
CONTINUES INTO FRIDAY NIGHT AND SATURDAY SO IT WOULD JUST SERVE
AS EXTRA LEAD TIME FOR THAT.

AFTER THE SHORTWAVE PASSES FRIDAY AFTERNOON...WINDS JUST ABOVE THE
SURFACE BECOME MORE SOUTHEASTERLY IN RESPONSE TO A DIGGING TROUGH
ON THE WEST COAST. THESE WINDS WILL START A STRONG WARM/MOIST
ADVECTION PATTERN WITH ISENTROPIC LIFT ORGANIZING OVER THE ENTIRE
REGION. THIS LIFT WILL BE SUSTAINED FROM FRIDAY NIGHT THROUGH
SUNDAY...WITH DRIZZLE AND LIGHT SHOWERS LIKELY ACROSS NORTH TEXAS.
MOS POPS LOOK MUCH TOO LOW GIVEN THE STRENGTH AND PERSISTENCE OF
THIS SIGNAL. THE ISSUE IS THAT TEMPERATURES WILL STILL BE BELOW
FREEZING AT THE SURFACE INTO SATURDAY. AND WHILE THE ENTIRE COLUMN
IS BELOW FREEZING FRIDAY NIGHT...THE PRECIPITATION TYPE COULD
SWITCH FROM LIGHT SNOW GRAINS TO FREEZING DRIZZLE. FROZEN
PRECIPITATION REQUIRES AN ICE NUCLEI BECAUSE WATER DOES NOT KNOW
HOW TO FORM INTO THE CRYSTAL STRUCTURE WITHOUT HELP. PURE WATER
DOES NOT FREEZE UNTIL -40C...BUT IN REAL WORLD CLOUDS...POLLEN AND
DIRT PARTICLES WILL /TEACH/ WATER HOW TO FREEZE AT TEMPS OF -8C.
SO ONCE TEMPERATURES IN THE CLOUD RISE ABOVE -8C BUT STAY BELOW
FREEZING...THERE WILL NO LONGER BE ICE IN THE CLOUD...AND
PRECIPITATION WILL BE SUPER COOLED RAINDROPS WHICH FREEZE ON
CONTACT WITH THE SURFACE. THIS TYPE OF FREEZING RAIN/DRIZZLE IS OF
THE HIGHEST IMPACT BECAUSE IT IS SO EFFICIENT AT GOING TO ICE
WHEN IT HITS THE SURFACE. AS A RESULT WE ARE CONCERNED THAT
BRIDGES AND OVERPASSES WILL RECEIVE A GLAZE OF ICE FRIDAY NIGHT
INTO SATURDAY. UNTIL TEMPS RISE ABOVE FREEZING SATURDAY
AFTERNOON...THIS WILL BE A BIG CONCERN FOR TRAVEL. WE EXPECT MOST
OF THE CWA...WITH PERHAPS THE EXCEPTION OF THE SOUTHEAST ZONES TO
CONTEND WITH THIS FREEZING PRECIP. THE WINTER WEATHER ADVISORY
WILL LIKELY BE EXPANDED TO INCLUDE ADDITIONAL COUNTIES DURING THE
NEXT 24 HOURS.

ONCE TEMPS RISE ABOVE FREEZING SATURDAY NIGHT WITH THE APPROACH
AND PASSAGE OF A WARM FRONT...JUST A CHANCE OF RAIN SHOWERS ARE
EXPECTED SUNDAY. THE FRONT WILL SLOSH BACK TO THE SOUTH ON MONDAY
WITH COOLER TEMPS AGAIN...BUT THEY WILL REMAIN ABOVE FREEZING. THE
CHANCE OF SHOWERS NEAR AND BEHIND THE FRONT WILL PERSIST. ON
TUESDAY A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH THE PLAINS AND
BRING MUCH WARMER GULF AIR INTO THE REGION WITH HIGHS IN THE 70S.
THIS WILL RESULT IN SOME SURFACE INSTABILITY...AND PERHAPS A
SEVERE WEATHER THREAT WHEN THE NEXT FRONT MOVES THROUGH TUESDAY.
THE SW FLOW BEHIND THE FRONT MAY MEAN IT IS NOT UNTIL WEDNESDAY
THAT THE RAIN AND CLOUDS CAN BE CLEARED FROM THE FORECAST...BUT
EVENTUALLY DRIER WEATHER WILL PREVAIL BY MID-LATE WEEK.

TR.92

&&

.AVIATION...
/ISSUED 1135 AM CST THU FEB 26 2015/

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  26  32  28  38  37 /   5  60  60  60  40
WACO, TX              28  35  30  40  39 /   5  20  40  60  40
PARIS, TX             23  30  26  38  37 /   5  50  60  60  40
DENTON, TX            24  30  26  36  35 /   5  70  60  60  40
MCKINNEY, TX          25  31  27  38  37 /   5  60  60  60  40
DALLAS, TX            26  32  29  39  38 /   5  60  50  60  40
TERRELL, TX           27  33  29  40  39 /   5  40  40  60  40
CORSICANA, TX         28  35  30  42  41 /   5  20  40  60  40
TEMPLE, TX            28  36  32  41  40 /   5  20  50  60  40
MINERAL WELLS, TX     25  29  26  35  34 /  10  70  60  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 PM CST SATURDAY
FOR TXZ091>095-100>106-115>120-129>133-141.


&&

$$

 /





000
FXUS64 KFWD 261735 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1135 AM CST THU FEB 26 2015

.AVIATION...

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75

&&

.UPDATE...
UPDATED FORECAST TO ADD A WINTER WEATHER ADVISORY FOR THE WESTERN
CWA. GETTING REPORTS OF ONE INCH OF SNOW ALREADY IN GRAHAM TO
MINERAL WELLS WHERE HEAVIER SNOW FELL THIS MORNING. ALREADY A FEW
TRAFFIC ISSUES WERE REPORTED NEAR GRAHAM...AND WITH THE SNOW
LIKELY TO CONTINUE THROUGH MIDDAY IT WAS PROBABLY BEST TO ISSUE AN
ADVISORY FOR THIS AREA. SNOW IS BEING FORCED IN A ZONE OF
FRONTOGENESIS...WHICH LOOKS TO BE ALIGNED IN A BAND FROM HASKELL
TO MINERAL WELLS TO HILLSBORO. THIS LIFT IS FORECAST TO SHUT DOWN
AROUND MIDDAY...BUT THIS AREA COULD SEE ANOTHER HALF INCH TO INCH
OF FLUFFY SNOW. FARTHER TO THE EAST...INCLUDING THE
METROPLEX...CONSIDERABLE DRY AIR IN THE LOW LEVELS AND A LACK OF A
GOOD MESOSCALE FORCING MECHANISM IN THIS AREA WARRANTS KEEPING
THE FORECAST OF JUST A DUSTING OF SNOW IN TACT.  TR.92

&&

.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  70   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR TXZ100-
101-115>117-129>132-141.


&&

$$

75/




000
FXUS64 KFWD 261735 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1135 AM CST THU FEB 26 2015

.AVIATION...

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75

&&

.UPDATE...
UPDATED FORECAST TO ADD A WINTER WEATHER ADVISORY FOR THE WESTERN
CWA. GETTING REPORTS OF ONE INCH OF SNOW ALREADY IN GRAHAM TO
MINERAL WELLS WHERE HEAVIER SNOW FELL THIS MORNING. ALREADY A FEW
TRAFFIC ISSUES WERE REPORTED NEAR GRAHAM...AND WITH THE SNOW
LIKELY TO CONTINUE THROUGH MIDDAY IT WAS PROBABLY BEST TO ISSUE AN
ADVISORY FOR THIS AREA. SNOW IS BEING FORCED IN A ZONE OF
FRONTOGENESIS...WHICH LOOKS TO BE ALIGNED IN A BAND FROM HASKELL
TO MINERAL WELLS TO HILLSBORO. THIS LIFT IS FORECAST TO SHUT DOWN
AROUND MIDDAY...BUT THIS AREA COULD SEE ANOTHER HALF INCH TO INCH
OF FLUFFY SNOW. FARTHER TO THE EAST...INCLUDING THE
METROPLEX...CONSIDERABLE DRY AIR IN THE LOW LEVELS AND A LACK OF A
GOOD MESOSCALE FORCING MECHANISM IN THIS AREA WARRANTS KEEPING
THE FORECAST OF JUST A DUSTING OF SNOW IN TACT.  TR.92

&&

.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  70   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR TXZ100-
101-115>117-129>132-141.


&&

$$

75/




000
FXUS64 KFWD 261735 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1135 AM CST THU FEB 26 2015

.AVIATION...

CONCERN...FLURRIES POSSIBLE THROUGH 19Z AND ANOTHER ROUND OF
LIGHT SNOW BEGIN MIDDAY FRIDAY.

KFWS 88D RADAR IS SHOWING THE LIGHT SNOW DIMINISHING AT MIDDAY BUT
THERE REMAINS SOME UPSTREAM ECHOES THAT WILL HAVE TO BE WATCHED.
HAVE ALLOWED THE AWW TO EXPIRE AT 17Z AND MAY HAVE TO BE
RE-ISSUED IF MORE LIGHT SNOW APPROACHES/MOVES OVER KDFW THIS
AFTERNOON. WOULD EXPECT THE THREAT OF LIGHT SNOW TO BE ALL OVER
WITH BY 21Z.

ANOTHER UPSTREAM SHORT WAVE WILL TRANSVERSE THE AREA ON FRIDAY
WITH ANOTHER ROUND OF LIGHT SNOW BEGINNING BY MIDDAY AND
CONTINUING THROUGH THE AFTERNOON. A WARMING WILL TAKE PLACE AROUND
5000 FEET AS WE MOVE INTO FRIDAY EVENING...THUS ANY REMAINING LIGHT
SNOW WILL TRANSITION TO LIGHT FREEZING DRIZZLE/SLEET FRIDAY
EVENING AROUND 28/03Z AND SHOULD PREVAIL MOST OF FRIDAY NIGHT.
SNOW ACCUMULATION OF AROUND ONE INCH IS EXPECTED FRIDAY...THEN ICE
ACCUMULATION OF A FEW HUNDREDTHS OF AN INCH ON FRIDAY NIGHT.

WINDS WILL BE NORTH 15 T0 25 THIS AFTERNOON...12 KNOTS OVERNIGHT
AND FRIDAY. MVFR CIGS AT KACT SHOULD BECOME VFR AROUND MID
AFTERNOON AND REMAIN SO OVERNIGHT...THEN BECOMING MVFR LATE
FRIDAY MORNING. VFR CONDITIONS ARE EXPECTED OVERNIGHT ACROSS THE
METROPLEX WITH CIGS RETURNING MVFR BY MIDDAY FRIDAY. KDFW HAS A
POTENTIAL FOR CIGS TO GO IFR AND MVFR VIS FRIDAY AFTERNOON IF ENHANCED
BANDS OF SNOW MOVE OVER THE AIRPORT. 75

&&

.UPDATE...
UPDATED FORECAST TO ADD A WINTER WEATHER ADVISORY FOR THE WESTERN
CWA. GETTING REPORTS OF ONE INCH OF SNOW ALREADY IN GRAHAM TO
MINERAL WELLS WHERE HEAVIER SNOW FELL THIS MORNING. ALREADY A FEW
TRAFFIC ISSUES WERE REPORTED NEAR GRAHAM...AND WITH THE SNOW
LIKELY TO CONTINUE THROUGH MIDDAY IT WAS PROBABLY BEST TO ISSUE AN
ADVISORY FOR THIS AREA. SNOW IS BEING FORCED IN A ZONE OF
FRONTOGENESIS...WHICH LOOKS TO BE ALIGNED IN A BAND FROM HASKELL
TO MINERAL WELLS TO HILLSBORO. THIS LIFT IS FORECAST TO SHUT DOWN
AROUND MIDDAY...BUT THIS AREA COULD SEE ANOTHER HALF INCH TO INCH
OF FLUFFY SNOW. FARTHER TO THE EAST...INCLUDING THE
METROPLEX...CONSIDERABLE DRY AIR IN THE LOW LEVELS AND A LACK OF A
GOOD MESOSCALE FORCING MECHANISM IN THIS AREA WARRANTS KEEPING
THE FORECAST OF JUST A DUSTING OF SNOW IN TACT.  TR.92

&&

.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  70   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR TXZ100-
101-115>117-129>132-141.


&&

$$

75/





000
FXUS64 KFWD 261550
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
950 AM CST THU FEB 26 2015

.UPDATE...
UPDATED FORECAST TO ADD A WINTER WEATHER ADVISORY FOR THE WESTERN
CWA. GETTING REPORTS OF ONE INCH OF SNOW ALREADY IN GRAHAM TO
MINERAL WELLS WHERE HEAVIER SNOW FELL THIS MORNING. ALREADY A FEW
TRAFFIC ISSUES WERE REPORTED NEAR GRAHAM...AND WITH THE SNOW
LIKELY TO CONTINUE THROUGH MIDDAY IT WAS PROBABLY BEST TO ISSUE AN
ADVISORY FOR THIS AREA. SNOW IS BEING FORCED IN A ZONE OF
FRONTOGENESIS...WHICH LOOKS TO BE ALIGNED IN A BAND FROM HASKELL
TO MINERAL WELLS TO HILLSBORO. THIS LIFT IS FORECAST TO SHUT DOWN
AROUND MIDDAY...BUT THIS AREA COULD SEE ANOTHER HALF INCH TO INCH
OF FLUFFY SNOW. FARTHER TO THE EAST...INCLUDING THE
METROPLEX...CONSIDERABLE DRY AIR IN THE LOW LEVELS AND A LACK OF A
GOOD MESOSCALE FORCING MECHANISM IN THIS AREA WARRANTS KEEPING
THE FORECAST OF JUST A DUSTING OF SNOW IN TACT.  TR.92

&&

.AVIATION...
/ISSUED 535 AM CST THU FEB 26 2015/
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30


&&

.AVIATION...
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30


&&



.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH




&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  70   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR TXZ100-
101-115>117-129>132-141.


&&

$$

 /




000
FXUS64 KFWD 261135
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
535 AM CST THU FEB 26 2015

.AVIATION...
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30

&&


.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$





000
FXUS64 KFWD 261135
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
535 AM CST THU FEB 26 2015

.AVIATION...
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30

&&


.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$





000
FXUS64 KFWD 261135
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
535 AM CST THU FEB 26 2015

.AVIATION...
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30

&&


.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$




000
FXUS64 KFWD 261135
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
535 AM CST THU FEB 26 2015

.AVIATION...
NORTH WINDS HAVE BEGUN GUSTING TO 25KT AT ALLIANCE AND SHOULD
FOLLOW SUIT SHORTLY ACROSS THE REST OF THE METROPLEX FOLLOWING
THE PASSAGE OF A STRONG COLD FRONT. THE FRONT IS NEARING THE WACO
AREA NOW...AND THE HIGHER WIND GUSTS CURRENTLY IN THE METROPLEX
CAN BE EXPECTED AT KACT AROUND 14Z. MVFR CIGS ARE OCCURRING IN
LINE WITH THE STRONGER NORTH WINDS...AND ARE ACCOMPANYING A 2-4
MILLIBAR 3-HR PRESSURE JUMP. UPSTREAM TRENDS INDICATE THAT THESE
CIGS WILL HOLD THROUGH MUCH OF THE MORNING WITH IMPROVEMENT
EXPECTED BY MID DAY.

RADAR INDICATES LIGHT SNOW JUST WEST OF THE AREA IN A REGION OF
ENHANCED LIFT ASSOCIATED WITH AN APPROACHING SHORTWAVE. THIS SNOW
SHOULD REACH THE METROPLEX AROUND 14Z...BUT ACCUMULATIONS SHOULD
REMAIN LIGHT. ACTIVITY WILL DISSIPATE AROUND MIDDAY AS THE UPPER
LEVER FEATURE RACES OFF TO THE EAST AND WEAK SUBSIDENCE DEVELOPS
OVERHEAD. WE WILL INCLUDE A TEMPO GROUP FOR -SN IN THE DALLAS FORT
WORTH AREA 14Z-17Z. IT APPEARS THAT ACTIVITY WILL BE EVEN LIGHTER
FARTHER SOUTH SO WE WILL HOLD OFF MENTIONING AT KACT.

WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE OVERNIGHT...THEN VEER
TO THE NORTHEAST FRIDAY MORNING. MORE LIGHT WINTER PRECIPITATION
WILL BE POSSIBLE FRIDAY AS ANOTHER SHORTWAVE QUICKLY TRANSLATES
THE REGION.

30

&&


.PREV DISCUSSION... /ISSUED 358 AM CST THU FEB 26 2015/

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$




000
FXUS64 KFWD 260958
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
358 AM CST THU FEB 26 2015

.DISCUSSION...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1140 PM CST WED FEB 25 2015/
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

 /





000
FXUS64 KFWD 260958
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
358 AM CST THU FEB 26 2015

.DISCUSSION...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1140 PM CST WED FEB 25 2015/
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

 /





000
FXUS64 KFWD 260958
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
358 AM CST THU FEB 26 2015

.DISCUSSION...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1140 PM CST WED FEB 25 2015/
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

 /




000
FXUS64 KFWD 260958
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
358 AM CST THU FEB 26 2015

.DISCUSSION...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED A RELATIVELY
STRONG...BUT FAST MOVING...SHORTWAVE TROUGH OVER EASTERN NEW
MEXICO...MOVING EAST-SOUTHEAST TOWARDS NORTH TEXAS. OUT AHEAD OF
THIS TROUGH...REGIONAL RADARS SHOWED WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM THE TEXAS/NEW MEXICO BORDER EAST TO
CHILDRESS. LIGHT RADAR RETURNS EXTENDED WELL EAST OF
CHILDRESS...AS FAR EAST AS BOWIE...HOWEVER OBSERVATIONS INDICATED
THAT NO PRECIPITATION WAS REACHING THE GROUND UNDER THESE RETURNS.
ASIDE FROM PRECIPITATION...SURFACE OBSERVATIONS ALSO SHOWED THE
LEADING EDGE OF A FAST-MOVING COLD FRONT MOVING SOUTH TOWARDS THE
INTERSTATE 20/30 CORRIDOR THIS MORNING. AT 3 AM...THE FRONT WAS
ACROSS DENTON BUT NOT YET TO DFW AIRPORT. THIS FRONT REPRESENTS
THE LEADING EDGE OF A COLD CANADIAN AIRMASS THAT WILL BUILD INTO
THE REGION IN THE FRONT`S WAKE.

TODAY...THE COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS ALL OF
NORTH TEXAS BY 12Z/6AM...AND IS EXPECTED TO PUSH ACROSS THE
CENTRAL TEXAS COUNTIES OF THE CWA BY 8 AM. AS COLD AIR BUILDS IN
BEHIND THE FRONT...THE NEW MEXICO SHORTWAVE TROUGH IS EXPECTED TO
MOVE EAST OVER THE CWA THIS MORNING...SPREADING SOME FAIRLY STRONG
LARGE SCALE FORCING FOR ASCENT OVER NORTH TEXAS. ALL GUIDANCE
INDICATES THAT SOME LIGHT PRECIPITATION WILL FALL ACROSS THE
REGION AS A RESULT. BECAUSE THE LIFT AND ASSOCIATED PRECIPITATION
ARE EXPECTED TO MOVE OVER THE CWA BEHIND THE COLD FRONT...ALL
MODEL GUIDANCE ONCE AGAIN INDICATES THAT WE WILL BE COLD ENOUGH
FOR PRECIPITATION TO FALL AS SNOW. A 245 AM AIRCRAFT SOUNDING FROM
ALLIANCE AIRPORT INDICATED THAT THE ATMOSPHERE WAS ABOVE FREEZING
FROM THE SURFACE TO ABOUT 5000 FEET ABOVE GROUND...WITH NO
SIGNIFICANT INVERSIONS PRESENT. AS A RESULT...IT SEEMS REASONABLE
THAT WE WILL COOL OFF QUICKLY FROM THE SURFACE TO 5000 FEET THIS
MORNING BEHIND THE FRONT...ALLOWING PRECIPITATION TO FALL AS SNOW.

WHILE THE LIFT ASSOCIATED WITH THIS UPPER TROUGH DOES LOOK
IMPRESSIVE...IT IS EXPECTED TO BE FAST MOVING. THE SPEED OF THE
UPPER TROUGH WILL LIKELY PREVENT MUCH IN THE WAY OF MODERATE TO
HEAVY SNOWFALL FROM DEVELOPING BECAUSE A LOT OF THE LIFT WILL BE
USED TO SIMPLY SATURATE THE ATMOSPHERE. SKIES WERE CLEAR OVER MOST
OF NORTH CENTRAL TEXAS OUT AHEAD OF THE FRONT...INDICATING THAT
THE ATMOSPHERE IS NOT SATURATED AT ANY LEVEL BEFORE LIFT ARRIVES.
AIRCRAFT SOUNDINGS FROM 11 PM (THE LAST TIME WATER VAPOR SOUNDINGS
WERE AVAILABLE) INDICATE THAT RELATIVE HUMIDITY VALUES RANGED FROM
30 TO 60 PERCENT FROM THE SURFACE TO 400 MB OVERNIGHT...SO A
DECENT AMOUNT OF LIFT WILL NEED TO TAKE PLACE TO FIRST SATURATE
THE ATMOSPHERE...AND SECOND...GENERATE PRECIPITATION. WITH NO
SIGNIFICANT POSITIVE MOISTURE ADVECTION FEEDING INTO THE REGION
AHEAD OF THE TROUGH...THINK THAT LIGHT SNOW OR FLURRIES WILL BE
THE MOST COMMON PRECIPITATION INTENSITY THIS MORNING.

MODELS DO INDICATE THE POTENTIAL FOR SOME BANDED SNOWFALL
ASSOCIATED WITH FRONTOGENETIC FORCING THIS MORNING. A CROSS
SECTIONAL ANALYSIS OUT AHEAD OF THIS TROUGH REVEALS THAT
FRONTOGENETIC FORCING DOES SET UP FOR A FEW HOURS THIS MORNING IN
BETWEEN WICHITA FALLS AND BRECKENRIDGE. THIS ENHANCED LIFT COULD
GENERATE SOME LOCALLY HIGHER SNOWFALL AMOUNTS ASSUMING THAT A BAND
OF LIGHT SNOW IS ABLE TO ORGANIZE. DUE TO DRY AIR ALREADY IN
PLACE...AND THE FAST MOVING NATURE OF THE UPPER TROUGH...THINK
THAT SNOWFALL AMOUNTS WILL RANGE FROM ABOUT ONE TENTH TO ONE
QUARTER OF AN INCH FROM THE DFW METROPLEX WEST AND NORTHWESTWARD.
IF A SNOW BAND DEVELOPS...IT APPEARS MOST LIKELY TO OCCUR
SOMEWHERE NORTHWEST OF A LINE FROM BRECKENRIDGE TO WEATHERFORD TO
BOWIE. THIS COULD RESULT IN ONE HALF INCH OF SNOWFALL IF THE BAND
DEVELOPS.

DID NOT ISSUE A WINTER WEATHER ADVISORY FOR THIS LIGHT SNOWFALL
THIS MORNING AS ADVERSE IMPACTS ARE EXPECTED TO BE LIMITED TO
NON-EXISTENT. WE WILL CLOSELY MONITOR THE POTENTIAL FOR SNOW
BANDING THIS MORNING...AS THIS COULD RESULT IN SOME QUICK SNOW
ACCUMULATIONS ON BRIDGES AND OVERPASSES WITH TEMPERATURES DROPPING
INTO THE UPPER 20S THIS MORNING BEHIND THE FRONT. ALL LIGHT SNOW
IS EXPECTED TO COME TO AN END AFTER NOON AS SUBSIDENCE SPREADS
OVER THE REGION BEHIND THE UPPER TROUGH.

SUBSIDENCE IS EXPECTED TO LAST FOR ONLY ABOUT 12 TO 18 HOURS FROM
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS ANOTHER FAST MOVING
BUT STRONG SHORTWAVE TROUGH APPROACHES THE REGION FROM THE
NORTHWEST. THIS TROUGH WAS CURRENTLY LOCATED OVER EASTERN
OREGON...AND IS EXPECTED TO MOVE OVER NORTH TEXAS FRIDAY MORNING.
WITH A COLD CANADIAN AIRMASS FIRMLY ENTRENCHED OVER THE
REGION...THIS TROUGH WILL INDUCE SOME DEEP LIFT IN THE FORM OF
WARM AIR ADVECTION OVER THE COLD AIR...RESULTING IN ANOTHER
POTENTIAL ROUND FOR LIGHT SNOWFALL ACROSS THE AREA. THE MAIN
DIFFERENCE WITH THIS SECOND TROUGH IS THAT MODERATE LIFT IS
EXPECTED TO BE PRESENT OVER THE CWA FOR A MUCH LONGER PERIOD OF
TIME COMPARED TO TODAY. THE TROUGH IS NOT REALLY STRONGER...WE
SIMPLY WILL HAVE DEEPER COLD AIR IN PLACE WHICH HELPS STEEPEN
ISENTROPIC SURFACES THEREBY ENHANCING LIFT ASSOCIATED WITH WARM
AIR ADVECTION ONCE IT ENSUES.

MORE PERSISTENT LIFT ADDS CONFIDENCE THAT MEASURABLE PRECIPITATION
WILL BE ABLE TO MAKE IT TO THE GROUND ON FRIDAY. THE STRONGEST
LIFT WILL REMAIN TIED TO THE EXACT TRACK OF THE SHORTWAVE TROUGH
AS IT MOVES OVER THE CWA FRIDAY. ITS EXACT TRACK IS STILL NOT
COMPLETELY AGREED UPON IN VARIOUS MODEL FORECASTS...HOWEVER THE
CONSENSUS TAKES THE TROUGH NORTHWEST OF THE DFW AREA. 850 MB
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING BEFORE THIS
TROUGH ARRIVES...SO CONFIDENCE IN ANY PRECIPITATION FALLING AS
SNOW IS VERY HIGH ON FRIDAY. ONCE AGAIN...ANY PRECIPITATION
GENERATED ALOFT WILL HAVE TO CONTEND WITH DRY AIR CLOSER TO THE
SURFACE...AND THIS DRY AIR SHOULD REALLY EAT UP A LOT OF POTENTIAL
SNOWFALL AWAY FROM THE STRONGEST FORCING ASSOCIATED WITH THE
TROUGH.

IF YOU`RE NOT IN THE TROUGH`S DIRECT PATH...SNOWFALL TOTALS ARE
EXPECTED TO RANGE FROM A DUSTING/TRACE TO ABOUT ONE HALF INCH ON
FRIDAY. IN THE TROUGH`S PATH...SNOWFALL TOTALS ARE MORE LIKELY TO
CLIMB TO 1 INCH OR SLIGHTLY ABOVE...DEPENDING ON THE POTENTIAL FOR
ANY BANDING/CONVECTION. FOR NOW...HAVE THE HIGHEST SNOWFALL TOTALS
HOLDING NORTHWEST OF THE DFW AREA WITH AN AVERAGE ACCUMULATION OF
1-2 INCHES IN THE FORECAST. FOR MOST OTHER AREAS...HAVE ABOUT ONE
HALF INCH OF SNOW IN THE FORECAST AT THIS TIME. THE PLACEMENT OF
THE HIGHER ACCUMULATION TOTALS WILL DEPEND ON THE EXACT TRACK OF
THE UPPER TROUGH...SO KEEP IN MIND THAT THIS MAY CHANGE IF THE
TRACK IS EXPECTED TO TAKE ON A MUCH DIFFERENT PATH THAN WHAT IS
CURRENTLY FORECAST.

THE UPPER TROUGH IS EXPECTED TO MOVE QUICKLY TO OUR NORTHEAST BY
FRIDAY EVENING AS A LARGE AND POWERFUL UPPER TROUGH BUILDS SOUTH
OVER THE WESTERN CONUS COAST. THIS LARGE TROUGH IS BIG ENOUGH TO
RESULT IN A LARGE SCALE FLOW REGIME CHANGE OVER THE ENTIRE CONUS
THIS WEEKEND. WE WILL TRANSITION FROM HAVING A LARGE UPPER TROUGH
OVER THE CENTRAL CONUS...TO AN UPPER AIR PATTERN DOMINATED BY
SOUTHWEST FLOW ALOFT BY SUNDAY AFTERNOON. THIS BIG PATTERN SHIFT
WILL RESULT IN PERSISTENT LEE SIDE CYCLOGENESIS OVER THE HIGH
PLAINS...AND WILL CAUSE PERSISTENT AND FAIRLY STRONG WARM AIR
ADVECTION TO DEVELOP OVER THE CWA FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT.

STRONG AND PERSISTENT WARM AIR ADVECTION WILL RESULT IN
LIGHT...BUT PERSISTENT PRECIPITATION TO DEVELOP AND FALL ACROSS
NORTH CENTRAL TEXAS FROM FRIDAY NIGHT THROUGH SATURDAY. WITH AN
ARCTIC AIRMASS INITIALLY IN PLACE...THIS LIGHT PRECIPITATION IS
EXPECTED TO START OF AS VERY LIGHT SNOW FRIDAY EVENING...BUT THEN
QUICKLY TRANSITION TO LIGHT SLEET...THEN FREEZING RAIN...AND
FINALLY OVER TO RAIN THROUGH SATURDAY AFTERNOON. THE TRANSITION
PERIOD FRIDAY NIGHT INTO SATURDAY MORNING POSES THE GREATEST
CONCERN TO THE REGION BECAUSE THIS MAY RESULT IN LIGHT ICE
ACCUMULATIONS FOR LARGE PORTIONS OF NORTH AND CENTRAL TEXAS.

PRECIPITATION IS EXPECTED TO BE LIGHT...BUT SEVERAL HOURS OF
LIGHT SLEET TRANSITIONING OVER TO FREEZING RAIN MAY RESULT IN A
FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION ON BRIDGES AND
OVERPASSES. THIS WOULD CERTAINLY MAKE FOR SOME DANGEROUS TRAVEL
ACROSS THE REGION THROUGH SATURDAY MORNING. IF THIS FORECAST HOLDS
THINK THAT WE WILL LIKELY NEED A WINTER WEATHER ADVISORY OR
FREEZING RAIN ADVISORY FOR THIS EVENT. DID NOT ISSUE AN ADVISORY
FOR THIS PERIOD TONIGHT BECAUSE WE HAVE THE POTENTIAL FOR 2 ROUNDS
OF LIGHT SNOWFALL TO GET THROUGH BEFORE THIS LIGHT ICING EVENT
TAKES SHAPE FRIDAY NIGHT AND SATURDAY MORNING.

TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING FROM SOUTH TO
NORTH ACROSS THE REGION SATURDAY LATE MORNING OR EARLY AFTERNOON.
LIGHT PRECIPITATION WILL LIKELY PERSIST THROUGHOUT THE DAY...BUT
AS LONG AS IT IS IN LIQUID FORM...IT SHOULD POSE NO ADDITIONAL
THREAT FOR ADVERSE DRIVING CONDITIONS ACROSS THE REGION.

REMAINDER OF THE FORECAST...

SOUTHWEST FLOW ALOFT LOOKS LIKE IT BRINGS AN ELEVATED MIXED LAYER
OVER THE SOUTH PLAINS BY SUNDAY. WHILE WARM AIR ADVECTION WILL
LIKELY PERSIST BELOW THE EML CAP...ANY PRECIPITATION IS EXPECTED
TO BE LIGHT.

THE SOUTHWEST FLOW ALOFT FLOW REGIME IS EXPECTED TO PERSIST FOR
MUCH OF THE WEEK. THIS FAVORS PERSISTENT WARM AIR ADVECTION AND
GULF MOISTURE ADVECTION INTO THE REGION...SO LEFT CHANCE POPS IN
FOR MOST PERIODS NEXT WEEK. IT WILL NOT RAIN EVERYDAY...HOWEVER
EACH DAY CONDITIONS ARE FAVORABLE FOR PRECIPITATION GIVEN ANY
ENHANCEMENT TO LIFT. THOSE ENHANCEMENTS TO LIFT ARE EXPECTED TO
EXIST IN THE FORM OF SHORTWAVE TROUGHS MOVING OVER THE REGION IN
THE SOUTHWEST FLOW ALOFT. BY TUESDAY...MOST MODELS SHOW THAT WE
HAVE ENOUGH MOISTURE IN PLACE FOR THUNDERSTORMS (THE NORMAL NON-
SLEET/SNOW VARIETY)...SO LEFT THUNDER IN THE FORECAST AT THIS
TIME. NO OTHER SIGNIFICANT CHANGES MADE TO THE PREVIOUS FORECAST.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1140 PM CST WED FEB 25 2015/
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  39  23  30  28  36 /  20   5  40  30  50
WACO, TX              41  26  37  30  41 /  10   5  20  30  50
PARIS, TX             36  21  30  25  35 /   5   5  50  30  30
DENTON, TX            37  21  29  26  35 /  20   5  50  40  50
MCKINNEY, TX          37  21  30  27  35 /  10   5  50  30  50
DALLAS, TX            38  24  31  28  37 /  20   5  40  30  50
TERRELL, TX           38  25  31  29  38 /  10   5  30  30  40
CORSICANA, TX         39  24  36  30  41 /  10   5   5  20  40
TEMPLE, TX            43  26  39  31  42 /   5   5  20  30  50
MINERAL WELLS, TX     37  21  29  26  34 /  40   5  40  40  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

 /




000
FXUS64 KFWD 260540
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1140 PM CST WED FEB 25 2015

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX

&&

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82




000
FXUS64 KFWD 260540
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1140 PM CST WED FEB 25 2015

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX

&&

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82





000
FXUS64 KFWD 260540
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1140 PM CST WED FEB 25 2015

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX

&&

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82




000
FXUS64 KFWD 260540
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1140 PM CST WED FEB 25 2015

.AVIATION...
QUITE A FEW CHALLENGES TO GO ALONG WITH A RELATIVELY QUIET
EVENING. FIRST OFF...THERE ARE AREAS OF LIGHT FOG ACROSS SEVERAL
OBSERVATION SITES TONIGHT...WITH ONLY A HANDFUL OF THEM REPORTING
LESS THAN 5SM VISIBILITY. THE FOG IS A BIT THICKER IN THOSE AREAS
WHICH RECEIVED A BIT MORE SNOW THIS MORNING. LIGHT FOG AT THE
AIRPORTS ARE POSSIBLE...WITH CURRENT THINKING IS THERE WILL NOT BE
MUCH IN THE WAY OF RESTRICTIONS AT THE TAF SITES.

THE NEXT CHALLENGE IS THE HIGH CLOUDS AND COLD FRONT...CURRENTLY
APPROACHING WICHITA FALLS AND ABILENE. THE FRONT WILL MOVE
THROUGH THE METROPLEX SITES BY 08Z...AND WACO BY 10Z. ALONG WITH
THE FRONT WILL BE A FEW LAYERS OF HIGH CLOUDS. MVFR CEILINGS WILL
BE POSSIBLE FOR A FEW HOURS IN THE EARLY MORNING...ALONG WITH A
SMALL POSSIBILITY OF SNOW FLURRIES. HIGH RESOLUTION MODELS ALL
SUGGEST A FEW FLURRIES WEST OF THE TAF SITES...BUT THERE IS A
SMALL POSSIBILITY OF SNOW MAKING IT TO THE EAST.

STRONG WINDS ARE EXPECTED TO LAG BEHIND THE ACTUAL FRONT BY THREE
HOURS OR SO...BUT WINDS WILL INCREASE OUT OF THE NORTH AROUND
16KTS WITH THE OCCASIONAL GUST TO 26KTS. BY LATE AFTERNOON...WINDS
WILL BEGIN TO DIMINISH.

FOX

&&

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82





000
FXUS64 KFWD 260402 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1002 PM CST WED FEB 25 2015

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.AVIATION...
/ISSUED 346 PM CST WED FEB 25 2015/
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&


.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82




000
FXUS64 KFWD 260402 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1002 PM CST WED FEB 25 2015

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.AVIATION...
/ISSUED 346 PM CST WED FEB 25 2015/
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&


.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82





000
FXUS64 KFWD 260402 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1002 PM CST WED FEB 25 2015

.UPDATE...
CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS THE REGION AHEAD OF A
COLD FRONT THAT ARRIVES OVERNIGHT TONIGHT. SOME LIGHT FOG IS
ALREADY DEVELOPING ACROSS OUR EASTERN COUNTIES WHERE HEAVIER SNOWFALL
AMOUNTS OCCURRED TODAY. PATCHY FOG IS EXPECTED ACROSS THE REGION
AND THIS COULD OCCUR IN AREAS WHERE THE TEMPERATURE FALLS TO OR
BELOW FREEZING...RESULTING IN FREEZING FOG. HOWEVER...MOST
GUIDANCE SUGGESTS THE WINDOW FOR FREEZING FOG THAT WOULD RESULT IN
A LIGHT ICE DEPOSIT ON ROADWAYS AND SURFACES IS BRIEF BEFORE THE
COLD FRONT ARRIVES AND IDEALLY CLEARS OUT ANY FOG. THE BEST
POTENTIAL FOR FREEZING FOG THAT MAY DEPOSIT A THIN LAYER OF ICE
WOULD BE OVER OUR EASTERN COUNTIES WHERE SOME SNOW REMAINS ON THE
GROUND. WILL CONTINUE TO MONITOR TRENDS OVERNIGHT FOR A POSSIBLE
FREEZING FOG ADVISORY IF VISIBILITIES DROP BELOW A MILE.

OTHERWISE...CLOUD COVER WILL INCREASE ACROSS THE REGION FROM NORTH
TO SOUTH TONIGHT AND TOMORROW AS THE COLD FRONT MOVES ACROSS THE
REGION. THE WINDS WITH THE FRONT WILL SHIFT TO THE NORTH AND
INCREASE TO 15 TO 20 MPH WITH GUSTS UP TO 30 MPH.

REGARDING THE SNOW POTENTIAL FOR THURSDAY...A STRONG DISTURBANCE
MOVING THROUGH THE BROAD TROUGH IS CURRENTLY APPROACHING THE
TEXAS PANHANDLE AND WILL SWING ACROSS THE REGION STARTING THURSDAY
MORNING. AS IT APPROACHES NORTH TEXAS...LIGHT SNOW IS EXPECTED TO
DEVELOP AS THE DISTURBANCE INDUCES ENOUGH LIFT COMBINED WITH SOME
FRONTOGENETICAL FORCING AROUND THE 700 MB LAYER. WE MAY SEE SOME
LIGHT SNOW IN OUR WESTERN AND/OR NORTHWESTERN COUNTIES BEFORE 6 AM
BUT MOST OF THE SNOWFALL WILL LIKELY OCCUR AFTER 6 AM.

MOST OF THE GUIDANCE INDICATES A NARROW BAND OF MODERATE SNOW MAY
DEVELOP SOMEWHERE ALONG AND/OR NORTH OF INTERSTATE 20 AND MOST
LIKELY TO THE WEST OF INTERSTATE 35/35W. WILL KEEP SNOWFALL TOTALS
LESS THAN 1 INCH IN THIS AREA BUT ITS POSSIBLE 1-2 INCHES OF SNOW
MAY FALL WITHIN A BAND OF SNOW. HOWEVER...GROUND TEMPERATURES ARE
WARM AFTER BEING IN THE 50S TODAY AND WHILE SOME SNOW WILL
ACCUMULATE ON THE GROUND AS SURFACE AIR TEMPERATURES WILL BE IN
THE UPPER 20S AND LOWER 30S...THINK SOME OF IT WILL MELT DUE TO
THE WARMER GROUND TEMPERATURES. DO NOT PLAN TO ISSUE ANY
ADVISORIES AT THIS TIME AS AMOUNTS AND IMPACTS ARE EXPECTED TO BE
MINIMAL. FINALLY...THE FALLING SNOW WILL BE BLOWN BY STRONG NORTH
WINDS BEHIND THE FRONT GUSTING UP TO 30 MPH WHICH MAY RESULT IN
SLIGHTLY REDUCED VISIBILITIES IN SOME LOCATIONS.

WITH THIS UPDATE...WILL INCREASE POPS TO 50 PERCENT IN OUR
NORTHWEST COUNTIES AND INCREASE SNOW AMOUNTS TO HALF AN INCH FOR
THE 6 AM- 6 PM TIMEFRAME TOMORROW. HAVE ALSO EXPANDED POPS AND
THE MENTION OF LIGHT SNOW SLIGHTLY FARTHER EAST THAN THE PREVIOUS
FORECAST BUT KEPT AMOUNTS AT OR LESS THAN 0.1 INCHES FOR MOST OF
THE AREA.

82/JLD

&&

.AVIATION...
/ISSUED 346 PM CST WED FEB 25 2015/
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&


.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 25 2015/
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /  10  30   5  30  30
WACO, TX              28  39  26  34  30 /  10  20   5  20  20
PARIS, TX             25  35  22  33  26 /  10  10   5  30  20
DENTON, TX            27  37  24  31  25 /  10  30   5  30  30
MCKINNEY, TX          27  38  23  31  26 /  10  20   5  30  20
DALLAS, TX            29  38  25  32  27 /  10  20   5  30  30
TERRELL, TX           27  37  25  33  28 /  10  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /  10  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /  10  10   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /  20  50   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

14/82




000
FXUS64 KFWD 252146
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
346 PM CST WED FEB 25 2015

.DISCUSSION...
THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE NEXT WEEK AND WE
WILL BE FOCUSING ON 3 SEPARATE CHANCES FOR WINTRY PRECIPITATION
OCCURRING OVER THE NEXT 3 DAYS. THE FIRST TWO SYSTEMS WILL RESULT
IN CHANCES FOR LIGHT SNOW FOR PARTS OF THE AREA. THE THIRD SYSTEM
ON SATURDAY HAS A POTENTIAL FOR FREEZING DRIZZLE/RAIN...AND COULD
RESULT IN MORE SIGNIFICANT TRAVEL IMPACTS. BEYOND SATURDAY...WE
WILL BE IN A WET PATTERN...WITH A CHANCE FOR SPRING-LIKE
THUNDERSTORMS COMING UP AROUND TUESDAY.

THIS MORNING/S UPPER LEVEL LOW DROPPED GENERALLY 1-3 INCHES IN A
BAND FROM THE CENTRAL CWA EAST-NORTHEAST INTO EAST TEXAS. WE HAVE
A SNOWFALL TOTAL MAP ON OUR WEB PAGE IF INTERESTED. THE UPPER LOW
HAS MOVED RAPIDLY EAST AND IN ITS WAKE SUNSHINE HAS RETURNED TO
ALL BUT THE EASTERN ZONES THIS AFTERNOON. TEMPERATURES IN THE
WESTERN ZONES HAVE REACHED THE UPPER 50S...AND WHILE NOT QUITE AS
WARM FARTHER EAST ALONG THE I-35 CORRIDOR...THE WARM AIR AND
SUNSHINE HAS MELTED MOST OF THE ICE AND SNOW. SOME ICE AND SNOW
WILL PERSIST OVER THE EASTERN ZONES WHERE THE HIGHER SNOW AMOUNTS
FELL...AND FREEZING OF RESIDUAL MOISTURE MAY RESULT IN ICY SPOTS
ON ROADS TONIGHT.

THE LIGHT WINDS AND GENERALLY CLEAR SKIES WILL PROMOTE GOOD
RADIATIONAL COOLING THIS EVENING...AND TEMPERATURES WILL DROP
TO...AND EVENTUALLY BELOW...CURRENT DEWPOINTS. THIS IS A GOOD
SETUP FOR FOG AND HAVE ADDED THAT TO THE FORECAST. SOME OF THIS
FOG MAY OCCUR AT TEMPS BELOW FREEZING WHICH COULD RESULT IN A
LITTLE ICE ACCRETION ON BRIDGES AND OVERPASSES. A STRONG COLD
FRONT WILL MOVE THROUGH AROUND DAYBREAK WHICH WILL MIX UP THE AIR
WITH STRONG NORTH WINDS AND DRIER AIR TO DISPERSE ANY FOG AND
SUBLIME ANY ICE AWAY TOMORROW MORNING.

THURSDAY SYSTEM...
THE MORNING FRONT WILL RESULT IN STRONG COLD ADVECTION OVER THE
REGION. THE TIGHTENING OF THE HORIZONTAL TEMPERATURE GRADIENT
OVER THE REGION...A PROCESS CALLED FRONTOGENESIS...IS ONE THAT
CREATES LIFT IN THE ATMOSPHERE...AND WILL OCCUR OVER OUR REGION
TOMORROW MORNING. THE LIFTING WILL CAUSE THE ATMOSPHERIC PROFILE
TO SATURATE WITH SOME PRECIPITATION DEVELOPING AFTER SUNRISE. IT
WILL BE VERY COLD ALOFT...AND ANY PRECIPITATION WILL BE LIGHT
SNOW. BECAUSE VIRTUALLY ALL GUIDANCE NOW SHOWS HINTS OF QPF...WE
WILL MENTION A SLIGHT CHANCE OF SNOW GENERALLY ALONG AND NORTH OF
I-20 TOMORROW. THE POPS ARE LOW BECAUSE MEASURABLE SNOW IS
UNLIKELY BUT I THINK MOST OF THE NORTHERN AND CENTRAL ZONES WILL
SEE AT LEAST SOME SNOW FLURRIES. NO SIGNIFICANT ACCUMULATION IS
EXPECTED WITH THIS SYSTEM.

FRIDAY SYSTEM...
TEMPERATURES WILL CONTINUE TO COOL AT ALL LEVELS OF THE ATMOSPHERE
AS THE ARCTIC AIRMASS POURS INTO THE REGION. THE SOURCE REGION OF
THIS AIRMASS IS VERY COLD WITH CURRENT AFTERNOON TEMPERATURES IN
CENTRAL CANADA NEAR 0F. THE UPPER LEVEL PATTERN...FEATURING A
LARGE STATIONARY BOWL SHAPED LONG-WAVE TROUGH OVER THE CENTRAL
U.S. IS ALSO ONE THAT IS FAVORABLE FOR ARCTIC AIR INTRUSIONS
HERE...THE EXTENT OF WHICH ARE OFTEN UNDERESTIMATED BY MODEL
GUIDANCE. OUR THERMAL PROFILES WILL DROP TO SOMETHING MORE
CHARACTERISTIC OF NORTHERN LATITUDES WITH 500-1000MB THICKNESS
NEAR 530DM ALONG THE RED RIVER TO 540DM IN THE SOUTHERN ZONES.
PRECIP THAT DEVELOPS IN THIS THERMAL PROFILE IS GOING TO BE SNOW.

AN OPEN SHORTWAVE TROUGH WILL SWING THROUGH THE REGION FROM THE
NORTHWEST ON FRIDAY. THE ISSUE IS THAT THERE IS JUST NOT A LOT OF
MOISTURE TO WORK WITH...AS IS TYPICALLY THE CASE WITH OPEN WAVE
TROUGHS MOVING INTO THE REGION FROM THE NORTHWEST. ALL SNOW WILL
HAVE TO WORK THROUGH A VERY DRY AIRMASS BELOW 5000 FEET BEFORE IT
CAN REACH THE GROUND. HAVING SAID THAT...FOR THE NORTHERN HALF OF
THE CWA...SNOW GROWTH IS GOING TO OCCUR IN THE FAVORABLE -10C TO
-20C RANGE FOR DENDRITES. AS A RESULT SNOW AMOUNTS MAY BE ENHANCED
BY FLUFFY...UNCHARACTERISTICALLY HIGH SNOW TO WATER RATIOS IN
EXCESS OF 10 TO 1. IN COMPARISON THE SNOW TO WATER RATIO THIS
MORNING WAS 5 TO 1...A VERY WET SLUSHY SNOW. GIVEN THE DENSE MID
AND HIGH CLOUD COVER...TEMPERATURES WILL LIKELY STAY BELOW
FREEZING ALL DAY. WHATEVER FALLS WILL STICK TO THE GROUND...AND
FOR THIS FORECAST WE BUMPED UP SNOW TOTALS TO A HALF INCH IN THE
NORTHWEST ZONES TO JUST A DUSTING FOR THE CENTRAL ZONES. THE
AIRMASS LOOKS TOO DRY FOR SIGNIFICANT ACCUMULATIONS IN THE
SOUTHEAST ZONES. THESE NUMBERS ARE IN LINE WITH LATEST SREF MEANS.
BUT WE WILL NEED TO WATCH THESE AMOUNTS CLOSELY IN THE MODELS OVER
THE NEXT DAY GIVEN AN INCH OR TWO OF SNOW ACCUMULATION WOULD BRING
TRAVEL IMPACTS AND WARRANT AN ADVISORY.

SATURDAY SYSTEM...
BY SATURDAY AN UPPER LEVEL LOW OVER CALIFORNIA WILL BEGIN TO DIG
SOUTHWARD AND RESULT IN INCREASING SOUTHERLY FLOW IN THE LOW TO
MID LEVELS. THE PROBLEM IS THAT THE ARCTIC AIRMASS WILL STILL BE
FIRMLY ENTRENCHED OVER THE REGION IN THE FIRST FEW THOUSAND FEET
ABOVE THE GROUND. 850MB WINDS INCREASE TO NEAR 50KT DURING THE DAY
AND STRONG WARM/MOIST ADVECTION IN THIS LAYER WILL PROBABLY RESULT
IN LIGHT RAIN OR DRIZZLE OVER THE REGION. THIS PATTERN OFTEN
BRINGS US A LONG PERIOD OF LIGHT DRIZZLE OR FOG...BUT WE ARE OFTEN
NOT BELOW FREEZING WHEN IT OCCURS. THE SURFACE AIRMASS IS EXPECTED
TO MODERATE SLOWLY FROM SOUTH TO NORTH...BUT WILL LIKELY STILL
REMAIN BELOW FREEZING FOR MUCH OF SATURDAY...ESPECIALLY OVER THE
NORTHERN ZONES. ALTHOUGH PRECIPITATION WILL BE LIGHT WITH LIQUID
AMOUNTS 1/10 OF AN INCH OR LESS...IF THIS ENDS UP BEING IN THE
FORM OF FREEZING DRIZZLE WITH TEMPS IN THE MID-UPPER 20S AS
CURRENTLY FORECAST...IT WILL ESSENTIALLY COAT ALL BRIDGES AND
OVERPASSES IN ICE. DRIVERS IN THESE SITUATIONS SEEM TO BE UNAWARE
OF THE DANGER AND VEHICLE WRECKS ARE NUMEROUS. WE STILL HAVE SOME
TIME TO WATCH THIS POTENTIAL ICE EVENT PLAY OUT...BUT IT IS ONE
THAT COULD IMPACT TRAVEL OVER A LARGE AREA.

SUNDAY AND BEYOND...
NOT A LOT OF TIME TO SPEND ON THIS PART OF THE FORECAST...BUT
ESSENTIALLY A WARM FRONT WILL MOVE THROUGH SATURDAY NIGHT AND END
ANY WINTER PRECIP POTENTIAL. WE WILL KEEP THE CHANCES OF SHOWERS
IN THE FORECAST AS THE OVER RUNNING PATTERN PERSISTS INTO MONDAY
WITH A QUASI STATIONARY COLD FRONT SOMEWHERE IN THE AREA. BY
TUESDAY THE UPPER LOW OVER CALIFORNIA KICKS OUT INTO THE PLAINS
WITH WARMER CONDITIONS AND SOME CONVECTIVE INSTABILITY SPREADING
INTO THE AREA. THIS MAY BRING A SHOT AT SOME THUNDERSTORMS BEFORE
ALL RAIN ENDS. EITHER WAY THE WET PATTERN IS GOOD NEW FOR DROUGHT
CONDITIONS AND HOPEFULLY WE WILL SEE SOME GOOD RAINS OUT OF THIS.

TR.92

&&

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  29  38  25  32  27 /   5  20   5  30  30
WACO, TX              28  39  26  34  30 /   5  10   5  20  20
PARIS, TX             25  35  22  33  26 /   5  20   5  30  20
DENTON, TX            27  37  24  31  25 /   5  20   5  30  30
MCKINNEY, TX          27  38  23  31  26 /   5  20   5  30  20
DALLAS, TX            29  38  25  32  27 /   5  20   5  30  30
TERRELL, TX           27  37  25  33  28 /   5  20   5  30  20
CORSICANA, TX         28  37  27  36  30 /   5  10   5  20  20
TEMPLE, TX            30  42  27  36  30 /   5   5   5  20  20
MINERAL WELLS, TX     30  37  23  31  24 /   5  20   5  40  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$




000
FXUS64 KFWD 251802 AAC
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1202 PM CST WED FEB 25 2015

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/

&&

.UPDATE...
WE ARE CLEARING THE ADVISORY FROM NORTHWEST TO SOUTHEAST
PERIODICALLY THIS MORNING AS THE BACK EDGE OF THE PRECIPITATION
ADVANCES SOUTHEAST. THE CORE OF THE UPPER LEVEL LOW ENDED UP
TRACKING JUST SOUTH OF THE I-20 CORRIDOR AND THAT IS THE LOCATION
WHERE THE DYNAMIC COOLING WAS GREAT ENOUGH TO OVERCOME THE LAYER
OF WARM AIR NEAR 5000FT BEFORE THE BRUNT OF THE PRECIP ENDED.
SNOWFALL TOTALS OF 2-5 INCHES ARE EXPECTED JUST SOUTH AND EAST OF
THE METROPLEX...IN A BAND FROM ROUGHLY NEAR HILLSBORO TO TERRELL.
SO FAR THE HIGHEST REPORT WAS OVER 3.5 INCHES IN WESTERN NAVARRO
COUNTY. WE WILL CONTINUE TO SEE ADDITIONAL MESOCALE BANDS OF
MODERATE SNOW SHOWERS DEVELOP ON THE BACKSIDE...OR NORTHWEST SIDE
OF THE UPPER LEVEL LOW THROUGH THE NEXT 2 TO 3 HOURS. THIS
ADDITIONAL ACTIVITY SHOULD PRODUCE NEW SNOW TOTALS OF UP TO 1
INCH IN MOST AREAS EAST OF A SHERMAN TO MCKINNEY TO MESQUITE TO
WAXAHACHIE LINE. THE FAR EASTERN ZONES MAY NEED A SHORT HOUR OR
TWO EXTENSION OF THE ADVISORY BUT WE WILL WAIT ON THIS DECISION.

CLEARING SKIES WILL RAPIDLY OCCUR FROM WEST TO EAST TODAY WITH
SUNSHINE EXPECTED TO BREAK OUT AS FAR EAST AS THE I-35 CORRIDOR BY
EARLY TO MID AFTERNOON. ANY SNOW ACCUMULTIONS SHOULD MELT AS
TEMPERATURES WARM INTO THE 40S...WITH SOME 50S LIKELY WEST OF
I-35. SOME GROUND SNOW WILL PERSIST INTO THE EVENING FOR AREAS
OVER THE EASTERN ZONES THAT RECEIVE MORE THAN 2 INCHES.

WE WILL BE TURNING OUR ATTENTION THIS AFTERNOON TO THE FORECAST
FOR TOMORROW THROUGH SATURDAY...AS IT APPEARS WINTER WEATHER IS
NOT OVER JUST YET.

TR.92

&&




.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  43  31  43  26  33 / 100   5  10  10  30
WACO, TX              49  30  47  28  37 /  90   5   5   5  20
PARIS, TX             39  29  41  23  32 / 100   5  10  10  30
DENTON, TX            45  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          41  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            42  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           40  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         44  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            53  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     51  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ094-095-
104>107-119>123-134-135-146>148.


&&

$$

 /05





000
FXUS64 KFWD 251802 AAC
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1202 PM CST WED FEB 25 2015

.AVIATION...
/18Z TAFS/

CONCERNS THE NEXT 24 HRS WILL BE LINGERING MVFR CIGS EARLY THIS
AFTERNOON...THEN THE POSSIBILITY OF LIGHT FOG AHEAD OF A COLD
FRONT SLATED INTO THE AREA BEFORE SUNRISE THURSDAY.

CURRENTLY...THE UPPER LOW THAT CAUSED ALL THE RAIN/SLEET/AND SNOW
EARLIER THIS MORNING IS NOW OPENING UP AND LIFTING OUT AWAY FROM
THE AREA QUICKLY. ANY MVFR CIGS EARLY THIS AFTERNOON WILL BE BRIEF
AND GIVE WAY TO CLEARING AND VFR CONDITIONS BY MID AFTERNOON AND
LASTING INTO EARLY EVENING.

WINDS WILL BE VERY LIGHT AHEAD OF THE APPROACHING COLD FRONT
TONIGHT. THE COMBINATION OF COLD/MOIST SOILS AND NEAR CALM WINDS
WILL LIKELY RESULT IN A SATURATED NEAR SURFACE LAYER WITH LIGHT
FLOW IN THE BOUNDARY LAYER. THIS SHOULD RESULT IN MVFR CONDITIONS
BY MID EVENING...WITH POSSIBLE IFR CONDITIONS AFTER MIDNIGHT. ONCE
THE COLD FRONT MOVES THROUGH...WE MAY SEE BRIEF MVFR CIGS THURSDAY
MORNING AS NORTH WINDS INCREASE TO BETWEEN 15 AND 20 MPH AND
GUSTY. VFR CONDITIONS WILL LIKELY RETURN BY MIDDAY.

.OUTLOOK...
ANOTHER MORE PROGRESSIVE AND WEAKER SYSTEM WILL ARRIVE BY FRIDAY
AND COULD GIVE ANOTHER BRIEF ROUND OF LIGHT SNOW AND LOWER
CIGS/VSBYS.

05/

&&

.UPDATE...
WE ARE CLEARING THE ADVISORY FROM NORTHWEST TO SOUTHEAST
PERIODICALLY THIS MORNING AS THE BACK EDGE OF THE PRECIPITATION
ADVANCES SOUTHEAST. THE CORE OF THE UPPER LEVEL LOW ENDED UP
TRACKING JUST SOUTH OF THE I-20 CORRIDOR AND THAT IS THE LOCATION
WHERE THE DYNAMIC COOLING WAS GREAT ENOUGH TO OVERCOME THE LAYER
OF WARM AIR NEAR 5000FT BEFORE THE BRUNT OF THE PRECIP ENDED.
SNOWFALL TOTALS OF 2-5 INCHES ARE EXPECTED JUST SOUTH AND EAST OF
THE METROPLEX...IN A BAND FROM ROUGHLY NEAR HILLSBORO TO TERRELL.
SO FAR THE HIGHEST REPORT WAS OVER 3.5 INCHES IN WESTERN NAVARRO
COUNTY. WE WILL CONTINUE TO SEE ADDITIONAL MESOCALE BANDS OF
MODERATE SNOW SHOWERS DEVELOP ON THE BACKSIDE...OR NORTHWEST SIDE
OF THE UPPER LEVEL LOW THROUGH THE NEXT 2 TO 3 HOURS. THIS
ADDITIONAL ACTIVITY SHOULD PRODUCE NEW SNOW TOTALS OF UP TO 1
INCH IN MOST AREAS EAST OF A SHERMAN TO MCKINNEY TO MESQUITE TO
WAXAHACHIE LINE. THE FAR EASTERN ZONES MAY NEED A SHORT HOUR OR
TWO EXTENSION OF THE ADVISORY BUT WE WILL WAIT ON THIS DECISION.

CLEARING SKIES WILL RAPIDLY OCCUR FROM WEST TO EAST TODAY WITH
SUNSHINE EXPECTED TO BREAK OUT AS FAR EAST AS THE I-35 CORRIDOR BY
EARLY TO MID AFTERNOON. ANY SNOW ACCUMULTIONS SHOULD MELT AS
TEMPERATURES WARM INTO THE 40S...WITH SOME 50S LIKELY WEST OF
I-35. SOME GROUND SNOW WILL PERSIST INTO THE EVENING FOR AREAS
OVER THE EASTERN ZONES THAT RECEIVE MORE THAN 2 INCHES.

WE WILL BE TURNING OUR ATTENTION THIS AFTERNOON TO THE FORECAST
FOR TOMORROW THROUGH SATURDAY...AS IT APPEARS WINTER WEATHER IS
NOT OVER JUST YET.

TR.92

&&




.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  43  31  43  26  33 / 100   5  10  10  30
WACO, TX              49  30  47  28  37 /  90   5   5   5  20
PARIS, TX             39  29  41  23  32 / 100   5  10  10  30
DENTON, TX            45  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          41  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            42  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           40  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         44  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            53  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     51  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ094-095-
104>107-119>123-134-135-146>148.


&&

$$

 /05




000
FXUS64 KFWD 251601
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1001 AM CST WED FEB 25 2015

.UPDATE...
WE ARE CLEARING THE ADVISORY FROM NORTHWEST TO SOUTHEAST
PERIODICALLY THIS MORNING AS THE BACK EDGE OF THE PRECIPITATION
ADVANCES SOUTHEAST. THE CORE OF THE UPPER LEVEL LOW ENDED UP
TRACKING JUST SOUTH OF THE I-20 CORRIDOR AND THAT IS THE LOCATION
WHERE THE DYNAMIC COOLING WAS GREAT ENOUGH TO OVERCOME THE LAYER
OF WARM AIR NEAR 5000FT BEFORE THE BRUNT OF THE PRECIP ENDED.
SNOWFALL TOTALS OF 2-5 INCHES ARE EXPECTED JUST SOUTH AND EAST OF
THE METROPLEX...IN A BAND FROM ROUGHLY NEAR HILLSBORO TO TERRELL.
SO FAR THE HIGHEST REPORT WAS OVER 3.5 INCHES IN WESTERN NAVARRO
COUNTY. WE WILL CONTINUE TO SEE ADDITIONAL MESOCALE BANDS OF
MODERATE SNOW SHOWERS DEVELOP ON THE BACKSIDE...OR NORTHWEST SIDE
OF THE UPPER LEVEL LOW THROUGH THE NEXT 2 TO 3 HOURS. THIS
ADDITIONAL ACTIVITY SHOULD PRODUCE NEW SNOW TOTALS OF UP TO 1
INCH IN MOST AREAS EAST OF A SHERMAN TO MCKINNEY TO MESQUITE TO
WAXAHACHIE LINE. THE FAR EASTERN ZONES MAY NEED A SHORT HOUR OR
TWO EXTENSION OF THE ADVISORY BUT WE WILL WAIT ON THIS DECISION.

CLEARING SKIES WILL RAPIDLY OCCUR FROM WEST TO EAST TODAY WITH
SUNSHINE EXPECTED TO BREAK OUT AS FAR EAST AS THE I-35 CORRIDOR BY
EARLY TO MID AFTERNOON. ANY SNOW ACCUMULTIONS SHOULD MELT AS
TEMPERATURES WARM INTO THE 40S...WITH SOME 50S LIKELY WEST OF
I-35. SOME GROUND SNOW WILL PERSIST INTO THE EVENING FOR AREAS
OVER THE EASTERN ZONES THAT RECEIVE MORE THAN 2 INCHES.

WE WILL BE TURNING OUR ATTENTION THIS AFTERNOON TO THE FORECAST
FOR TOMORROW THROUGH SATURDAY...AS IT APPEARS WINTER WEATHER IS
NOT OVER JUST YET.

TR.92


&&

.AVIATION...
/ISSUED 717 AM CST WED FEB 25 2015/
PRECIPITATION CURRENTLY SWITCHING TO LIGHT SNOW AT THE FWD
OFFICE...

WE ARE LOOKING TO DO SOME AMENDING TO REMOVE THE MENTION OF
MOD/HVY SNOW IN THE DALLAS-FORT WORTH AREA TAFS. THERE WILL STILL
BE LIGHT SNOW/SLEET FOR A WHILE THIS MORNING...BUT IT LOOKS LIKE
A MUCH HEAVIER BAND OF SNOW WILL PASS JUST SOUTH OF I-20 NEAR THE
CORE OF THE UPPER LOW. THE MORE SIGNIFICANT ACCUMULATIONS...THEREFORE...ARE
BECOMING MORE LIKELY IN THE REGION BETWEEN DFW AND ACT.

30


&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  43  31  43  26  33 / 100   5  10  10  30
WACO, TX              49  30  47  28  37 /  90   5   5   5  20
PARIS, TX             39  29  41  23  32 / 100   5  10  10  30
DENTON, TX            45  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          41  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            42  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           40  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         44  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            53  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     51  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ093>095-
103>107-118>123-133>135-144>148-157-159-161.


&&

$$

 /





000
FXUS64 KFWD 251317
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
717 AM CST WED FEB 25 2015

.AVIATION...
PRECIPITATION CURRENTLY SWITCHING TO LIGHT SNOW AT THE FWD
OFFICE...

WE ARE LOOKING TO DO SOME AMENDING TO REMOVE THE MENTION OF
MOD/HVY SNOW IN THE DALLAS-FORT WORTH AREA TAFS. THERE WILL STILL
BE LIGHT SNOW/SLEET FOR A WHILE THIS MORNING...BUT IT LOOKS LIKE
A MUCH HEAVIER BAND OF SNOW WILL PASS JUST SOUTH OF I-20 NEAR THE
CORE OF THE UPPER LOW. THE MORE SIGNIFICANT ACCUMULATIONS...THEREFORE...ARE
BECOMING MORE LIKELY IN THE REGION BETWEEN DFW AND ACT.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69




000
FXUS64 KFWD 251317
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
717 AM CST WED FEB 25 2015

.AVIATION...
PRECIPITATION CURRENTLY SWITCHING TO LIGHT SNOW AT THE FWD
OFFICE...

WE ARE LOOKING TO DO SOME AMENDING TO REMOVE THE MENTION OF
MOD/HVY SNOW IN THE DALLAS-FORT WORTH AREA TAFS. THERE WILL STILL
BE LIGHT SNOW/SLEET FOR A WHILE THIS MORNING...BUT IT LOOKS LIKE
A MUCH HEAVIER BAND OF SNOW WILL PASS JUST SOUTH OF I-20 NEAR THE
CORE OF THE UPPER LOW. THE MORE SIGNIFICANT ACCUMULATIONS...THEREFORE...ARE
BECOMING MORE LIKELY IN THE REGION BETWEEN DFW AND ACT.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69





000
FXUS64 KFWD 251317
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
717 AM CST WED FEB 25 2015

.AVIATION...
PRECIPITATION CURRENTLY SWITCHING TO LIGHT SNOW AT THE FWD
OFFICE...

WE ARE LOOKING TO DO SOME AMENDING TO REMOVE THE MENTION OF
MOD/HVY SNOW IN THE DALLAS-FORT WORTH AREA TAFS. THERE WILL STILL
BE LIGHT SNOW/SLEET FOR A WHILE THIS MORNING...BUT IT LOOKS LIKE
A MUCH HEAVIER BAND OF SNOW WILL PASS JUST SOUTH OF I-20 NEAR THE
CORE OF THE UPPER LOW. THE MORE SIGNIFICANT ACCUMULATIONS...THEREFORE...ARE
BECOMING MORE LIKELY IN THE REGION BETWEEN DFW AND ACT.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69




000
FXUS64 KFWD 251317
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
717 AM CST WED FEB 25 2015

.AVIATION...
PRECIPITATION CURRENTLY SWITCHING TO LIGHT SNOW AT THE FWD
OFFICE...

WE ARE LOOKING TO DO SOME AMENDING TO REMOVE THE MENTION OF
MOD/HVY SNOW IN THE DALLAS-FORT WORTH AREA TAFS. THERE WILL STILL
BE LIGHT SNOW/SLEET FOR A WHILE THIS MORNING...BUT IT LOOKS LIKE
A MUCH HEAVIER BAND OF SNOW WILL PASS JUST SOUTH OF I-20 NEAR THE
CORE OF THE UPPER LOW. THE MORE SIGNIFICANT ACCUMULATIONS...THEREFORE...ARE
BECOMING MORE LIKELY IN THE REGION BETWEEN DFW AND ACT.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69





000
FXUS64 KFWD 251157
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
557 AM CST WED FEB 25 2015

.AVIATION...
A LARGE SWATH OF PRECIPITATION EXTENDS ACROSS NORTH TEXAS IN
ADVANCE OF AN UPPER LEVEL LOW PRESSURE SYSTEM...THE CENTER OF WHICH
APPEARED TO BE LOCATED NEAR MKN AT 530 AM. PRECIPITATION WAS IN
THE PROCESS OF TRANSITIONING FROM RAIN TO SLEET IN THE
METROPLEX...AND SHOULD BECOME PRIMARILY SNOW AS THE UPPER LOW
MOVES OVERHEAD DURING THE NEXT COUPLE OF HOURS. WE HAVE INDICATED
RAPL SWITCHING TO RASN IN THE CURRENT TAFS. WE WILL ALSO INDICATE
A TEMPO GROUP FOR HEAVIER SNOW WITH LOWER VISIBILITIES FROM 13Z TO
15Z. HIGH REFLECTIVITY UPSTREAM NEAR THE CENTER OF THE LOW IS
LIKELY INDICATIVE OF A MODERATE TO HEAVY BAND OF SNOW...WHICH
COULD STILL BRING WET SNOW ACCUMULATIONS OF 1 TO 4 INCHES DURING A
BRIEF PERIOD FROM 13 TO 15Z. LIGHT SNOW SHOULD THEN LINGER UNTIL
16Z OR 17Z WITH IMPROVING CONDITIONS THEREAFTER. THE EXACT TIMING
OF THE END OF LIGHT SNOW MAY NEED TO BE ADJUSTED A LITTLE IN THE
CURRENT TAF SET DEPENDING ON TRENDS LATER THIS MORNING.

FOR WACO...A RAIN/SNOW MIX APPEARS MOST LIKELY...BUT WE COULD
STILL SEE SOME ACCUMULATIONS OF AN INCH OR SO OF SNOW BY THE TIME
PRECIP ENDS LATE MORNING. OTHERWISE...WE SHOULD SEE CONDITIONS
IMPROVING TO VFR THIS AFTERNOON AS THE SYSTEM EXITS TO THE EAST.

FOR THURSDAY...WE WILL SEE A COLD FRONT PUSH SOUTH THROUGH THE
METROPLEX AROUND 10Z...THEN WACO 12-14Z.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69




000
FXUS64 KFWD 251157
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
557 AM CST WED FEB 25 2015

.AVIATION...
A LARGE SWATH OF PRECIPITATION EXTENDS ACROSS NORTH TEXAS IN
ADVANCE OF AN UPPER LEVEL LOW PRESSURE SYSTEM...THE CENTER OF WHICH
APPEARED TO BE LOCATED NEAR MKN AT 530 AM. PRECIPITATION WAS IN
THE PROCESS OF TRANSITIONING FROM RAIN TO SLEET IN THE
METROPLEX...AND SHOULD BECOME PRIMARILY SNOW AS THE UPPER LOW
MOVES OVERHEAD DURING THE NEXT COUPLE OF HOURS. WE HAVE INDICATED
RAPL SWITCHING TO RASN IN THE CURRENT TAFS. WE WILL ALSO INDICATE
A TEMPO GROUP FOR HEAVIER SNOW WITH LOWER VISIBILITIES FROM 13Z TO
15Z. HIGH REFLECTIVITY UPSTREAM NEAR THE CENTER OF THE LOW IS
LIKELY INDICATIVE OF A MODERATE TO HEAVY BAND OF SNOW...WHICH
COULD STILL BRING WET SNOW ACCUMULATIONS OF 1 TO 4 INCHES DURING A
BRIEF PERIOD FROM 13 TO 15Z. LIGHT SNOW SHOULD THEN LINGER UNTIL
16Z OR 17Z WITH IMPROVING CONDITIONS THEREAFTER. THE EXACT TIMING
OF THE END OF LIGHT SNOW MAY NEED TO BE ADJUSTED A LITTLE IN THE
CURRENT TAF SET DEPENDING ON TRENDS LATER THIS MORNING.

FOR WACO...A RAIN/SNOW MIX APPEARS MOST LIKELY...BUT WE COULD
STILL SEE SOME ACCUMULATIONS OF AN INCH OR SO OF SNOW BY THE TIME
PRECIP ENDS LATE MORNING. OTHERWISE...WE SHOULD SEE CONDITIONS
IMPROVING TO VFR THIS AFTERNOON AS THE SYSTEM EXITS TO THE EAST.

FOR THURSDAY...WE WILL SEE A COLD FRONT PUSH SOUTH THROUGH THE
METROPLEX AROUND 10Z...THEN WACO 12-14Z.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69





000
FXUS64 KFWD 251157
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
557 AM CST WED FEB 25 2015

.AVIATION...
A LARGE SWATH OF PRECIPITATION EXTENDS ACROSS NORTH TEXAS IN
ADVANCE OF AN UPPER LEVEL LOW PRESSURE SYSTEM...THE CENTER OF WHICH
APPEARED TO BE LOCATED NEAR MKN AT 530 AM. PRECIPITATION WAS IN
THE PROCESS OF TRANSITIONING FROM RAIN TO SLEET IN THE
METROPLEX...AND SHOULD BECOME PRIMARILY SNOW AS THE UPPER LOW
MOVES OVERHEAD DURING THE NEXT COUPLE OF HOURS. WE HAVE INDICATED
RAPL SWITCHING TO RASN IN THE CURRENT TAFS. WE WILL ALSO INDICATE
A TEMPO GROUP FOR HEAVIER SNOW WITH LOWER VISIBILITIES FROM 13Z TO
15Z. HIGH REFLECTIVITY UPSTREAM NEAR THE CENTER OF THE LOW IS
LIKELY INDICATIVE OF A MODERATE TO HEAVY BAND OF SNOW...WHICH
COULD STILL BRING WET SNOW ACCUMULATIONS OF 1 TO 4 INCHES DURING A
BRIEF PERIOD FROM 13 TO 15Z. LIGHT SNOW SHOULD THEN LINGER UNTIL
16Z OR 17Z WITH IMPROVING CONDITIONS THEREAFTER. THE EXACT TIMING
OF THE END OF LIGHT SNOW MAY NEED TO BE ADJUSTED A LITTLE IN THE
CURRENT TAF SET DEPENDING ON TRENDS LATER THIS MORNING.

FOR WACO...A RAIN/SNOW MIX APPEARS MOST LIKELY...BUT WE COULD
STILL SEE SOME ACCUMULATIONS OF AN INCH OR SO OF SNOW BY THE TIME
PRECIP ENDS LATE MORNING. OTHERWISE...WE SHOULD SEE CONDITIONS
IMPROVING TO VFR THIS AFTERNOON AS THE SYSTEM EXITS TO THE EAST.

FOR THURSDAY...WE WILL SEE A COLD FRONT PUSH SOUTH THROUGH THE
METROPLEX AROUND 10Z...THEN WACO 12-14Z.

30

&&

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH



&&

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

30/69





000
FXUS64 KFWD 251130
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
530 AM CST WED FEB 25 2015

.UPDATE...

THE BIGGEST FORECAST CONCERN CONTINUES TO BE HOW MUCH SNOWFALL WE
WILL RECEIVE ACROSS NORTH CENTRAL TEXAS OVER THE NEXT 8 TO 12
HOURS. VIRTUALLY ALL EFFORTS WERE SPENT ANALYZING THIS SHORT TERM
EVENT...SO NO SIGNIFICANT CHANGES WERE MADE TO THE REMAINDER OF
THE FORECAST.

REGIONAL RADARS SHOWED WIDESPREAD PRECIPITATION OVER THE
REGION. SURFACE OBSERVATIONS AND PHONE CALLS TO COUNTY OFFICIALS
INDICATE THAT THIS PRECIPITATION IS FALLING PRIMARILY AS A COLD
RAIN EARLY THIS MORNING. EARLY MORNING AIRCRAFT SOUNDINGS FROM
AROUND THE DFW AREA INDICATE THAT A POCKET OF WARM AIR LOCATED
APPROXIMATELY 4000 TO 8000 FEET ABOVE GROUND LEVEL IS THE PRIMARY
REASON THAT PRECIPITATION IS FALLING AS RAIN AND NOT AS SNOW AT
THIS TIME. SURFACE TEMPERATURES WERE HOLDING IN THE LOW 30S ACROSS
THE REGION...BUT UNLIKE WITH FREEZING RAIN...THE SURFACE
TEMPERATURES WILL NOT PLAY A SIGNIFICANT ROLE IN DETERMINING
PRECIPITATION TYPE WITH THIS EVENT. THE SURFACE TEMPERATURES
CERTAINLY MAKE A GREAT DEAL OF DIFFERENCE REGARDING THE IMPACTS
FROM ANY SNOW THAT FALLS...HOWEVER TRACKING THE CHANGE OVER FROM
RAIN TO SNOW IS NOT AS SIMPLE AS LOOKING FOR WHERE GROUND
TEMPERATURES ARE ABOVE OR BELOW 32 DEGREES.

EARLY MORNING AIRCRAFT DATA HAVE BEEN INDICATING A PROGRESSIVE
COOLING OF THIS WARM NOSE ALOFT. THE PLUS 5 DEG C WARM NOSE HAD
COOLED TO PLUS 2.5 DEG C IN ABOUT ONE HOUR FROM 4 TO 5 AM. IF THIS
TREND CONTINUES...A TRANSITION FROM RAIN TO SNOW WOULD OCCUR OVER
THE DFW AREA SHOULD OCCUR IN THE 6 TO 7 AM TIMEFRAME. WE WILL
CONTINUE TO MONITOR AIRCRAFT TEMPERATURE DATA THIS MORNING AS THIS
WILL DETERMINE WHEN RAINFALL WILL CHANGE OVER TO SNOW.

AS MENTIONED IN THE 415 AM QUICK SYNOPSIS AFD VIRTUALLY ALL SHORT
RANGE/HIGH RESOLUTION GUIDANCE INDICATED SNOWFALL TOTALS IN EXCESS
OF 4 INCHES FROM THE DFW AREA NORTHEAST TO PARIS AND EAST ALONG
THE INTERSTATE 20 CORRIDOR TO TYLER. MOST OF THOSE MODELS HAD A
CHANGE OVER FROM RAIN TO SNOW OCCURRING BETWEEN 3 TO 4 AM
HOWEVER...SO AT LEAST SOME PERCENTAGE OF THIS MODEL SNOWFALL IS
CURRENTLY FALLING AS RAIN. REGARDLESS...WITH THE UPPER LOW THAT IS
PROVIDING STRONG LIFT FOR ALL OF THIS PRECIPITATION STILL WEST OF
THE AREA...THINK THAT A CHANGE OVER TO ALL SNOW IS STILL LIKELY
THIS MORNING. 00Z RAOB ANALYSIS SHOWED FREEZING TEMPERATURES FROM
850 THROUGH 700 MB JUST EAST OF THIS UPPER LOW OVER THE SOUTHERN
HIGH PLAINS. THE PERSISTENT DYNAMIC LIFT COMBINED WITH COOLER AIR
LOCATED ON THE EAST SIDE OF THE UPPER LOW SHOULD BE SUFFICIENT TO
BRING ABOUT THIS CHANGE OVER.

ASSUMING A CHANGE OVER TO SNOW DOES HAPPEN AS EXPECTED...SNOWFALL
IS EXPECTED TO BE MODERATE TO HEAVY FOR A FEW HOURS BEFORE
TAPERING OFF AND QUICKLY COMING TO AN END BY LATE THIS MORNING. IF
RAIN CHANGES OVER TO SNOW BEFORE 7 AM...EXPECT 3 TO 5 INCHES OF
SNOW IS POSSIBLE FROM THE DFW AREA NORTHEAST TO PARIS AND EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER. THIS SNOW WOULD
LIKELY BE VERY WET/SLUSHY IN NATURE...REDUCING THE IMPACTS TO
ROADWAYS. OUR PRIMARY CONCERN FOR ADVERSE IMPACTS IS TIED TO THE
POTENTIAL FOR CONVECTIVE SNOWBANDING.

REGIONAL RADARS SHOWED AN INTENSE BAND OF CONVECTION FROM MINERAL
WELLS SOUTHWEST TO BROWNWOOD AT 515 AM. IF THIS BAND CHANGES OVER
TO ALL SNOW...OR ANOTHER BAND OF SIMILAR INTENSITY DEVELOPS OVER
NORTH CENTRAL TEXAS THIS MORNING...SNOWFALL RATES OF 1-2 INCHES
PER HOUR COULD BE REALIZED. IF ONE OF THESE INTENSE BANDS WERE
UNFORTUNATE ENOUGH TO DEVELOP RIGHT OVER THE DFW AREA DURING RUSH
HOUR...REDUCED VISIBILITY AND TEMPORARILY SLICK ROADS COULD HAVE A
VERY HIGH IMPACT ON THE TRAFFIC PATTERN UNDER THE SNOW BAND. WE
WILL SIMPLY HAVE TO MONITOR SHORT TERM RADAR TRENDS AND PROVIDE
UPDATES VIA GRAPHICS AND SPECIAL WEATHER STATEMENTS IF IT LOOKS
LIKE THIS IS GOING TO TAKE PLACE.

BY NOON...THE UPPER LEVEL LOW IS EXPECTED TO MOVE EAST OF NORTH
CENTRAL TEXAS RESULTING IN STRONG SUBSIDENCE OVER THE REGION. THIS
SHOULD ALLOW FOR CLEARING SKIES AND TEMPERATURES WARMING UP INTO
THE MID TO UPPER 30S WHEREVER THIS IS SNOW ON THE GROUND...AND
INTO THE MID TO UPPER 40S WHERE THE GROUND REMAINS SNOW FREE.
EITHER WAY...ANY SNOW THAT ACCUMULATES IS LIKELY TO EXPERIENCE
QUITE A BIT OF MELTING THIS AFTERNOON ACROSS THE REGION.

ANY SNOW THAT REMAINS ON THE GROUND AFTER SUNSET MAY FREEZE INTO
ICY PATCHES ON ROADWAYS BY EARLY TOMORROW MORNING WITH LOWS
EXPECTED TO FALL JUST BELOW FREEZING FOR MOST LOCATIONS. THINK
THAT MOST SNOW...AGAIN ASSUMING WE SEE THE CHANGEOVER AND
ACCUMULATIONS THAT WE EXPECT...WILL MELT BEFORE SUNSET.

A STRONG COLD FRONT WILL MOVE ACROSS THE AREA EARLY THURSDAY...AND
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW FREEZING THURSDAY
NIGHT AS A RESULT. ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
MOVE OVER THE REGION ON FRIDAY BEHIND THIS FRONT...AND LIGHT SNOW
MAY DEVELOP OVER THE REGION WHENEVER THE BEST LIFT OCCURS. AT THIS
TIME...THERE WAS QUITE A BIT OF UNCERTAINTY REGARDING HOW MUCH
LIFT AND MOISTURE WILL BE AVAILABLE FOR THIS SYSTEM. JUST HAVE
LIGHT SNOW WITH MINIMAL ACCUMULATIONS IN THE FORECAST FOR
NOW...BUT THESE DETAILS WILL BE RESOLVED MUCH BETTER OVER THE NEXT
24 TO 36 HOURS. AT THIS TIME...HEAVY SNOW IS NOT EXPECTED ACROSS
THE REGION...BUT SOME LIGHT ACCUMULATIONS ARE POSSIBLE.

CAVANAUGH

&&

.AVIATION...
/ISSUED 1142 PM CST TUE FEB 24 2015/
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD


&&


.PREV DISCUSSION... /ISSUED 415 AM CST WED FEB 25 2015/

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH

&&


.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /




000
FXUS64 KFWD 251015
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
415 AM CST WED FEB 25 2015

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH


&&

.DISCUSSION...

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH

&&

.AVIATION...
/ISSUED 1142 PM CST TUE FEB 24 2015/
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /




000
FXUS64 KFWD 251015
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
415 AM CST WED FEB 25 2015

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH


&&

.DISCUSSION...

A SCIENTIFIC DISCUSSION WILL BE ISSUED LATER THIS MORNING.

CAVANAUGH

&&

.AVIATION...
/ISSUED 1142 PM CST TUE FEB 24 2015/
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  31  43  26  33 / 100   5  10  10  30
WACO, TX              46  30  47  28  37 /  90   5   5   5  20
PARIS, TX             35  29  41  23  32 / 100   5  10  10  30
DENTON, TX            38  28  42  23  32 / 100   5  10  10  30
MCKINNEY, TX          36  26  41  24  32 / 100   5  10   5  30
DALLAS, TX            37  32  43  27  34 / 100   5  10   5  30
TERRELL, TX           36  31  44  27  35 / 100   5  10   5  30
CORSICANA, TX         41  31  45  28  37 / 100   5  10   5  20
TEMPLE, TX            50  31  50  28  38 /  80   5   5   5  20
MINERAL WELLS, TX     39  29  43  22  31 /  90   5  10  10  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /





000
FXUS64 KFWD 250542 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1142 PM CST TUE FEB 24 2015

.AVIATION...
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD

&&

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&


.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

82/58




000
FXUS64 KFWD 250542 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1142 PM CST TUE FEB 24 2015

.AVIATION...
/06Z TAFS/

CONCERNS...CONDITIONS WILL DETERIORATE INTO IFR CONDITIONS
OVERNIGHT AS RAIN AND SNOW OCCURS ACROSS THE AREA.

LIGHT RAIN...POSSIBLY MIXED WITH SOME SLEET IS MOVING INTO AREAS
WEST OF THE AIRPORTS AT THIS HOUR. A MIX OF LIGHT RAIN/SLEET/SNOW
WILL CONTINUE TO SPREAD ACROSS THE REGION TONIGHT WITH A
TRANSITION TO ALL SNOW AT THE METROPLEX AIRPORTS BY 10-11Z. THE
SNOW MAY BE MODERATE TO HEAVY AT TIMES WITH VISBYS LESS THAN A
MILE. AT KACT...IT LOOKS LIKE A TRANSITION TO ALL SNOW WILL OCCUR
AROUND 13Z. THE RAIN/SNOW WILL MOVE EAST OF THE AIRPORTS BY
15-16Z. CIGS WILL LOWER INTO IFR CATEGORY AS THE TRANSITION TO
SNOW OCCURS. AFTER THE PRECIPITATION ENDS...MVFR CIGS WILL
PREVAIL...EVENTUALLY IMPROVING TO VFR IN THE AFTERNOON. A COLD
FRONT WILL ARRIVE THURSDAY MORNING AND WILL HAVE A WIND SHIFT IN
THE KDFW EXTENDED TAF. OTHERWISE...MOSTLY LIGHT AND VARIABLE
WINDS WILL PREVAIL BUT MAY BECOME LIGHT WESTERLY ON WEDNESDAY.

82/JLD

&&

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&


.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

82/58





000
FXUS64 KFWD 250333
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
933 PM CST TUE FEB 24 2015

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&

.AVIATION...
/ISSUED 643 PM CST TUE FEB 24 2015/
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&




.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /58




000
FXUS64 KFWD 250333
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
933 PM CST TUE FEB 24 2015

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&

.AVIATION...
/ISSUED 643 PM CST TUE FEB 24 2015/
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&




.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /58





000
FXUS64 KFWD 250333
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
933 PM CST TUE FEB 24 2015

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&

.AVIATION...
/ISSUED 643 PM CST TUE FEB 24 2015/
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&




.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /58




000
FXUS64 KFWD 250333
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
933 PM CST TUE FEB 24 2015

.UPDATE...
EXPECT SNOW TO COMMENCE ACROSS THE WESTERN ZONES BY MIDNIGHT AND
SPREAD NORTHEAST ACROSS THE FORECAST AREA OVERNIGHT THROUGH
WEDNESDAY. THE 00Z NAM CONTINUES TO SHOW SOME BANDED CONVECTIVE
ELEMENTS WHICH COULD RESULT IN LOCALLY HEAVY SNOWFALL AMOUNTS
ESPECIALLY ALONG AND NORTH OF I-20/I-30. FOR NOW...WE HAVE
DECIDED TO KEEP THE WINTER WEATHER ADVISORY FOR THE ENTIRE
FORECAST AREA BUT WILL MENTION 2 TO 4 INCHES POSSIBLE NORTH OF A
MINERAL WELLS TO DALLAS TO SULPHUR SPRINGS LINE WITH LOCALLY
HEAVIER AMOUNTS POSSIBLE.

WE MAY END UP HAVING TO UPGRADE THE NORTHERN PART OF ADVISORY IF
WE GET STRONGER CONVECTIVE BANDS TO DEVELOP ALONG AND NORTH AND
THE I-20/I-30 CORRIDOR.

58

&&

.AVIATION...
/ISSUED 643 PM CST TUE FEB 24 2015/
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD


&&




.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  90   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  70  90   5  10  10
DENTON, TX            29  47  28  42  23 /  80  90   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  90   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  90   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  90   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-157-159-161.


&&

$$

 /58





000
FXUS64 KFWD 250043 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
643 PM CST TUE FEB 24 2015

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD

&&

.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  80   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  60  80   5  10  10
DENTON, TX            29  47  28  42  23 /  80  70   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  80   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  80   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  80   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-157-159-
161.


&&

$$

82/58




000
FXUS64 KFWD 250043 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
643 PM CST TUE FEB 24 2015

.AVIATION...
/00Z TAFS/

CONCERNS...MVFR AND IFR CIGS. A RAIN/SNOW MIX OVERNIGHT
TRANSITIONING TO ALL SNOW AT DFW AND POSSIBLY WACO.

KACT...MVFR CIGS BELOW 2KFT WILL CONTINUE INTO WEDNESDAY MORNING.
THE PRECIPITATION FORECAST IS CHALLENGING...BUT STILL EXPECTING A
MIX OF RAIN AND SNOW...WITH POSSIBLY A BRIEF PERIOD OF
SLEET...BETWEEN 09-15Z. IT IS LIKELY THAT FOR A PERIOD OF TIME
BETWEEN 11-14Z...ALL SNOW COULD OCCUR WITH < 1" ACCUMULATION. WILL
CONTINUE TO MONITOR THE DATA THIS EVENING TO TRY AND PINPOINT
IF/WHEN A TRANSITION TO ALL SNOW WILL OCCUR...BUT IT DOES LOOK
LIKE THE HEAVIEST SNOW BANDS WILL OCCUR NORTH OF KACT. THE WINDS
THROUGH THE PERIOD WILL MOSTLY BE LIGHT AND VARIABLE BUT WILL
PREVAIL MORE FROM THE WEST ON WEDNESDAY. AS THE PRECIPITATION ENDS
WEDNESDAY MORNING...CIGS WILL IMPROVE TO VFR BY THE AFTERNOON.

DFW AIRPORTS...SCATTERED MVFR CIGS ARE OCCURRING ACROSS THE
METROPLEX THIS EVENING...RESULTING IN OCCASIONAL BKN CIGS BETWEEN
2500-3000 FEET. WILL CARRY A TEMPO FOR BKN025 FOR A FEW HOURS BUT
EXPECT MOSTLY VFR CONDITIONS TO PREVAIL THIS EVENING. AS THE
PRECIPITATION MOVES INTO THE DFW METROPLEX BETWEEN 07-09Z...IT
WILL INITIALLY BE A RAIN/SNOW MIX WITH POSSIBLY SOME SLEET MIXING
AT TIMES. BY 11-12Z...EXPECT THE MIX TO TRANSITION TO ALL SNOW
WITH MODERATE TO HEAVY SNOW POSSIBLE IN SNOW BANDS BETWEEN
12-15Z. ACCUMULATIONS OF SNOW WILL AVERAGE 1-3" WITH SOME LOCALLY
HIGHER AMOUNTS. THERE IS STILL SOME UNCERTAINTY IF ANY OR ALL OF
THE AIRPORTS WILL BE AFFECTED BY HEAVY SNOW BANDS...BUT CONFIDENCE
IS INCREASING THAT THE DFW AIRPORTS MAY BE AFFECTED BY A SNOW
BAND. WHEN THE PRECIPITATION ARRIVES...EXPECT CIGS TO LOWER INTO
LOW MVFR CATEGORY AND LIKELY IFR WITHIN PERIODS OF MODERATE TO
HEAVY SNOW. VISBY WILL ALSO BE AFFECTED. THE SNOW IS EXPECTED TO
END BETWEEN 15-16Z WITH THE VISBY AND CIGS IMPROVING TO VFR IN THE
AFTERNOON. EXPECT LIGHT AND VARIABLE WINDS THROUGH MOST OF THE
PERIOD BUT THEY MAY PREVAIL MORE FROM THE WEST ON WEDNESDAY.

82/JLD

&&

.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

&&


.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  80   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  60  80   5  10  10
DENTON, TX            29  47  28  42  23 /  80  70   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  80   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  80   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  80   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-157-159-
161.


&&

$$

82/58





000
FXUS64 KFWD 242201
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
401 PM CST TUE FEB 24 2015

...THE WINTER STORM WATCH HAS BEEN UPGRADED TO A WINTER WEATHER
ADVISORY...THE ONGOING ADVISORY WILL CONTINUE ELSEWHERE...

.SYNOPSIS...
RAIN WILL INVADE FROM THE SOUTHWEST LATE THIS EVENING...WITH
PRECIPITATION SPREADING ACROSS MUCH OF NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT. INITIALLY RAIN...A TRANSITION TO SNOW OR A
RAIN/SNOW MIX WILL BEGIN DURING THE PREDAWN HOURS WEDNESDAY. RAIN
AND SNOW WILL BEGIN SHIFTING EASTWARD AFTER DAYBREAK...EXITING THE
REGION BY EARLY AFTERNOON. SNOWFALL TOTALS ARE EXPECTED TO EXCEED
1/2 INCH WITHIN THE ADVISORY AREA...WITH LESSER BUT POTENTIALLY
ACCUMULATING SNOWFALL POSSIBLE TO THE SOUTH. THE AXIS OF GREATEST
SNOWFALL IS STILL EXPECTED NEAR THE I-20 AND I-30 CORRIDORS...
WHERE AMOUNTS WILL GENERALLY BE 1 TO 3 INCHES. ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE...PARTICULARLY EAST AND NORTHEAST OF THE
DALLAS/FORT WORTH METROPLEX.

.SHORT TERM...
DESPITE TEMPERATURES REMAINING BELOW FREEZING INTO THE AFTERNOON
HOURS...AND LINGERING CLOUD COVER...RESIDUAL ICE ON ROADWAYS HAS
EFFECTIVELY MELTED TODAY. IN ADDITION TO SUBLIMATION FROM THE TOP
OF THE ICE LAYER...DIFFUSE SUNLIGHT HAS BEEN SUFFICIENT TO WARM
THE PAVEMENT AND MELT THE ICE FROM BELOW. WITH TEMPERATURES ABOVE
FREEZING THIS EVENING...A REFREEZE OF ANY MELTWATER IS NOT
EXPECTED. THUS...ANY IMPACTS TO TRAVEL LATE TONIGHT AND WEDNESDAY
MORNING WILL BE A RESULT OF NEW PRECIPITATION.

AN UPPER LOW...RESPONSIBLE FOR THE THUNDERSTORMS IN THE MOUNTAINS
OF CENTRAL ARIZONA...WILL RACE INTO WEST TEXAS THIS EVENING.
GUIDANCE REMAINS IN EXCELLENT AGREEMENT WITH RESPECT TO THE TIMING
OF ITS PASSAGE THROUGH NORTH AND CENTRAL TEXAS. HOWEVER...THE
CRUCIAL DISPARITY AMONG OPERATIONAL SOLUTIONS WITH THE TRACK OF
THE FEATURE REMAINS...MAINTAINING A LEVEL OF UNCERTAINTY IN THE
EVOLUTION OF THE PRECIPITATION TONIGHT AND WEDNESDAY.

UNDETERRED BY THE CONSENSUS...THE 18Z NAM CONTINUES TO BE BULLISH
ON SNOW. THIS IS LARGELY A FACTOR OF ITS BOWLING BALL LOW IN THE
MID-LEVELS THAT TAKES A TRACK BETWEEN I-20 AND THE RED RIVER. WITH
SUFFICIENT COLD AIR...THIS IS ONE OF THE MOST FAVORABLE SETUPS FOR
SIGNIFICANT SNOWFALL IN THIS REGION. THE SCENARIO BEARS SOME
SIMILARITY TO THE SNOW EVENT OF FEBRUARY 3-4 OF 2011...WHICH WAS
THE SECOND OF A TRIO OF WINTER WEATHER EVENTS IN AN OTHERWISE
PLACID WINTER SEASON. WHILE THAT EVENT RESULTED IN SNOWFALL
AMOUNTS EXCEEDING WARNING CRITERIA FROM DALLAS TO SULPHUR
SPRINGS...THE ARE SOME MITIGATING FACTORS WITH THIS EVENT.

MITIGATING FACTORS
- SURFACE TEMPERATURES ARE 10-15 DEGREES WARMER THAN THE DAY THAT
  PRECEDED THE FEBRUARY 2011 EVENT. NO LOW-LEVEL COLD ADVECTION
  IS EXPECTED...AND DYNAMIC COOLING ALONE IS UNLIKELY TO RESULT
  IN SUB-FREEZING TEMPERATURES THROUGHOUT THE PRECIPITATION
  EVENT.
- THIS SYSTEM WILL SWING THROUGH MUCH FASTER...LIMITING
  THE DURATION OF THE PRECIPITATION...ONLY A PORTION OF WHICH
  WILL BE SNOW.
- IN ADDITION...THE CONSENSUS (GFS/ECMWF/CANADIAN) FAVORS AN
  OPENING RATHER THAN DEEPENING WAVE...LIMITING THE SCALE OF THE
  ASSOCIATED LIFT.

THERMAL PROFILES SUGGEST THE PRECIPITATION WILL BEGIN AS RAIN. AS
THE UPPER LOW APPROACHES...DYNAMIC COOLING OF THE COLUMN WILL
GRADUALLY RESULT IN A TRANSITION TO SNOW OR A RAIN/SNOW MIX. ITS
PASSAGE AT THE DIURNAL MINIMUM OF TEMPERATURE WILL AID IN THIS
TRANSITION TO FROZEN PRECIPITATION. THIS TRANSITION MAY NOT OCCUR
IN SOUTHERN ZONES (OUTSIDE OF THE ADVISORY AREA) UNTIL DAYBREAK.
SURFACE TEMPERATURES WILL BE NEAR OR ABOVE FREEZING WHEN THIS
TRANSITION OCCURS...LIMITING THE EVENTUAL ACCUMULATIONS.
HOWEVER...THIS WET SNOW SHOULD COOL THE SURFACE LAYER A FEW
DEGREES...AND IN THE BAND OF HEAVIEST PRECIPITATION...THE SNOWFALL
RATES ALONE SHOULD ASSURE SOME ACCUMULATIONS ARE REALIZED. THE
RESULT WILL BE SHORT DURATION EVENT OF MODERATE IMPACT...BUT ONE
THAT DIRECTLY IMPACTS MORNING COMMUTE TIME

THE CONSENSUS OF SYNOPTIC GUIDANCE IS FOR A MORE SOUTHERLY SWATH
OF PRECIPITATION...WHICH WOULD LIMIT SNOWFALL TOTALS. BUT A TRACK
JUST ONE COUNTY (30 MILES) TO THE NORTH OR SOUTH COULD MAKE THE
DIFFERENCE BETWEEN NEGLIGIBLE ACCUMULATIONS AND MESOSCALE-ENHANCED
TOTALS IN EXCESS OF 3 INCHES. THE WRF SUITE WAS FAVORING A MORE
NORTHERLY TRACK...BUT CONFIDENCE IN THESE SOLUTIONS DECLINED WITH
THE LATEST TTU WRF AND REMARKABLY DRY RAP. THE TIME FRAME OF THE
EVENT WILL BE CAPTURED BY ADDITIONAL MESOSCALE GUIDANCE AVAILABLE
THIS EVENING...AND THE TRACK OF HEAVIEST PRECIPITATION AND
RESULTING SNOWFALL AMOUNTS MAY NEED TO BE ADJUSTED.

EVEN WHERE SIGNIFICANT SNOWFALL OCCURS...TEMPERATURES WILL RISE
ABOVE FREEZING WEDNESDAY AFTERNOON...RESULTING IN EFFICIENT
MELTING OF THE WET SNOW. THE AFTERNOON BUS RIDE AND THE EVENING
COMMUTE SHOULD BE LARGELY FREE OF IMPACTS.

&&

.LONG TERM...
A BROAD BOWL SHAPED UPPER TROUGH WILL ENCOMPASSES THE COUNTRY
FRIDAY WITH A ANOTHER QUICK MOVING UPPER LEVEL DISTURBANCE
ROTATING IN FROM THE NORTHWEST. THIS SYSTEM WILL REMAIN AN OPEN
WAVE TROUGH AND THEREFORE DYNAMIC FORCING WILL BE MUCH
WEAKER...BUT IT WILL BE ABLE TO SQUEEZE OUT THE AVAILABLE MOISTURE
FOR CLOUD COVER AND PRECIPITATION. ACROSS NORTH TEXAS ON FRIDAY...
TEMPERATURES WILL STRUGGLE TO WARM DUE TO CONTINUED COLD ADVECTION
IN THE WAKE OF THURSDAYS FRONT AND INCREASING MID-HIGH CLOUDS IN
ADVANCE OF THE UPPER DISTURBANCE. HIGHS MAY STAY BELOW FREEZING
ACROSS THE NORTHWEST HALF OF THE CWA...WHERE THE COLUMN SHOULD
SATURATE SUFFICIENTLY BY THE AFTERNOON HOURS FOR LIGHT SNOW TO
BEGIN TO REACH THE GROUND. RIGHT NOW WE DO NOT ANTICIPATE THIS
SYSTEM TO PRODUCE MORE THAN AN INCH OF SNOW...AND CLIMATOLOGICALLY
SPEAKING OPEN WAVE TROUGHS THAT MOVE IN FROM THE NORTHWEST ARE
USUALLY STARVED FOR SIGNIFICANT MOISTURE TO HELP PRODUCE HIGHER
AMOUNTS. NONETHELESS THIS SNOW MAY BE FLUFFIER THAN NORMAL...AND
THE COLD SURFACE TEMPERATURES SUGGEST IT WILL STICK. AS YOU HEAD
FARTHER SOUTHEAST...PRECIPITATION WILL BECOME LIGHTER WITH LIQUID
RAIN BECOMING THE DOMINANT PRECIP TYPE.

SOUTHERLY LOW LEVEL FLOW ABOVE THE SURFACE WILL RAMP UP FRIDAY
NIGHT AND INTO SATURDAY WHICH WILL RESULT IN INCREASING LOW CLOUDS
AND PERHAPS SOME LIGHT PRECIPITATION MAINLY OVER THE WESTERN
ZONES. SOME OF THIS PRECIPITATION MAY BE LIGHT FREEZING RAIN
SATURDAY MORNING IN THE WESTERN ZONES...BUT AT THIS TIME THERE IS
NOTHING TO SUGGEST THIS WILL BE ANYTHING MORE THAN A NUISANCE
EVENT. TEMPS WILL SLOWLY CLIMB DURING THE DAY SATURDAY WITH TEMPS
LIKELY CONTINUING TO RISE STEADILY SATURDAY NIGHT WITH A WARM
FRONT MOVING NORTH THROUGH THE AREA. THIS USUALLY SPELLS DAMP AND
COOL CONDITIONS WITH SOME FOG AND LIGHT SHOWERS POSSIBLE. BY
SUNDAY...HIGH TEMPERATURES SHOULD WARM TO NEAR NORMAL BUT AS A
STRONG SHORTWAVE TROUGH MOVES THROUGH IT WILL SEND THE WARM FRONT
BACK TO THE SOUTH AS A COLD FRONT SUNDAY NIGHT. THE LIFT FROM THE
SHORTWAVE TROUGH AND COLD FRONT WILL RESULT IN A ROUND OF SHOWERS
AND A FEW STORMS...WITH BEST COVERAGE OVER THE EASTERN ZONES WHERE
MOISTURE AND INSTABILITY WILL BE HIGHEST.

THE SUNDAY NIGHT FRONT LOOKS LIKE IT WILL BECOME STATIONARY ACROSS
CENTRAL TEXAS IN SOUTHWEST FLOW ALOFT...AND IT WILL AWAIT ANOTHER
STRONG DISTURBANCE ON TUESDAY BEFORE IT IS FINALLY KICKED INTO THE
GULF. THE CHANCE FOR MORE RAIN AND A FEW STORMS WILL RAMP UP AGAIN
TUESDAY WITH THIS FINAL SHORTWAVE TROUGH...BUT AFTER THAT IT
SHOULD BE DRY AND COOL FOR A COUPLE DAYS.

TR.92

&&

.AVIATION...
/ISSUED 1158 AM CST TUE FEB 24 2015/
MVFR CIGS HAVE BEEN CLEARING THE METROPLEX TAF SITES FROM NW TO SE
THIS MORNING AND ALL SITES SHOULD BE VFR THIS AFTERNOON AND
EVENING. MVFR CIGS AT WACO WILL TAKE A LITTLE LONGER LIFT/SCATTER
OUT BUT WILL HAVE THEM VFR BY 22Z.

MAIN CONCERN IS OBVIOUSLY THE POTENTIAL FOR SNOW TONIGHT AND
WEDNESDAY MORNING AS STRONG UPPER LOW MOVES ACROSS. PRECIP WILL
START TO LIGHT UP THE RADARS AFTER MIDNIGHT...WITH RAIN SHOWERS
POSSIBLE BY 8Z/2AM. RAIN WILL LIKELY MIX TO AND/OR CHANGE OVER TO
SNOW BY 10Z/4AM WHEN THE COLUMN COOLS DUE TO EVAPORATION AND
DYNAMIC COOLING. MODEL GUIDANCE CONTINUES TO DISPLAY A LARGE
NORTH-SOUTH SPREAD IN THE PLACEMENT OF THE QPF WITH MOST SYNOPTIC
MODELS SUGGESTING THE HEAVIEST PRECIP WILL BE SOUTH OF METROPLEX
TAF SITES. THE HI-RES AND VARIOUS WRF MODELS ARE UNANIMOUSLY
FARTHER NORTH WITH PRECIP...LIKELY HANDLING THE MESOSCALE WRAP-
AROUND BANDING BETTER. WE WILL SIDE WITH THE LATTER GROUP OF THE
MODELS FOR THIS FORECAST...AND WILL SHOW A PERIOD OF SNOW FROM
11Z/5AM TO 15Z/9AM AT METROPLEX TAF SITES. THE POTENTIAL FOR HEAVY
SNOW REDUCING VSBY TO 1/2SM OR LESS EXISTS...BUT CONFIDENCE IS NOT
ESPECIALLY HIGH AT THIS POINT. THUS WILL SHOW A PROB30 GROUP FROM
12Z/6AM TO 14Z/8AM AS THIS WOULD BE THE MOST LIKELY WINDOW FOR
SUCH ACTIVITY. TEMPERATURES WILL BE ABOVE FREEZING THIS EVENING
AND LIKELY NOT FALL TO NEAR OR BELOW FREEZING UNTIL AFTER SNOW
STARTS FALLING. ALL PRECIP WILL END BY MID-MORNING WITH CLEARING
SKIES AND RAPIDLY WARMING TEMPS TOMORROW AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL VARY QUITE A BIT DUE TO THE MESOSCALE NATURE OF
THE BANDING...BUT METROPLEX AIRPORTS SHOULD PROBABLY PREPARE FOR
WORST CASE SCENARIO OF 2 TO 4 INCHES OF WET SLUSHY SNOW...WITH
LESSER AMOUNTS MORE LIKELY.

AIRPORT WEATHER WARNING FOR DFW WILL BE ISSUED THIS AFTERNOON TO
ADDRESS THE SNOW POTENTIAL.

TR.92

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  30  46  31  43  26 /  80  80   5  10   5
WACO, TX              32  50  30  47  28 /  70  60   5   5  10
PARIS, TX             28  37  29  41  23 /  60  80   5  10  10
DENTON, TX            29  47  28  42  23 /  80  70   5  10   5
MCKINNEY, TX          29  43  26  41  24 /  80  80   5  10  10
DALLAS, TX            30  45  32  43  27 /  80  80   5  10   5
TERRELL, TX           30  41  31  44  27 /  80  80   5  10  10
CORSICANA, TX         31  45  31  45  28 /  80  80   5  10  10
TEMPLE, TX            32  53  31  50  28 /  60  50   5   5  10
MINERAL WELLS, TX     29  53  29  43  22 /  80  50   5  10   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-157-159-
161.


&&

$$

92/25/91




000
FXUS64 KFWD 241758
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1158 AM CST TUE FEB 24 2015

.AVIATION...
MVFR CIGS HAVE BEEN CLEARING THE METROPLEX TAF SITES FROM NW TO SE
THIS MORNING AND ALL SITES SHOULD BE VFR THIS AFTERNOON AND
EVENING. MVFR CIGS AT WACO WILL TAKE A LITTLE LONGER LIFT/SCATTER
OUT BUT WILL HAVE THEM VFR BY 22Z.

MAIN CONCERN IS OBVIOUSLY THE POTENTIAL FOR SNOW TONIGHT AND
WEDNESDAY MORNING AS STRONG UPPER LOW MOVES ACROSS. PRECIP WILL
START TO LIGHT UP THE RADARS AFTER MIDNIGHT...WITH RAIN SHOWERS
POSSIBLE BY 8Z/2AM. RAIN WILL LIKELY MIX TO AND/OR CHANGE OVER TO
SNOW BY 10Z/4AM WHEN THE COLUMN COOLS DUE TO EVAPORATION AND
DYNAMIC COOLING. MODEL GUIDANCE CONTINUES TO DISPLAY A LARGE
NORTH-SOUTH SPREAD IN THE PLACEMENT OF THE QPF WITH MOST SYNOPTIC
MODELS SUGGESTING THE HEAVIEST PRECIP WILL BE SOUTH OF METROPLEX
TAF SITES. THE HI-RES AND VARIOUS WRF MODELS ARE UNANIMOUSLY
FARTHER NORTH WITH PRECIP...LIKELY HANDLING THE MESOSCALE WRAP-
AROUND BANDING BETTER. WE WILL SIDE WITH THE LATTER GROUP OF THE
MODELS FOR THIS FORECAST...AND WILL SHOW A PERIOD OF SNOW FROM
11Z/5AM TO 15Z/9AM AT METROPLEX TAF SITES. THE POTENTIAL FOR HEAVY
SNOW REDUCING VSBY TO 1/2SM OR LESS EXISTS...BUT CONFIDENCE IS NOT
ESPECIALLY HIGH AT THIS POINT. THUS WILL SHOW A PROB30 GROUP FROM
12Z/6AM TO 14Z/8AM AS THIS WOULD BE THE MOST LIKELY WINDOW FOR
SUCH ACTIVITY. TEMPERATURES WILL BE ABOVE FREEZING THIS EVENING
AND LIKELY NOT FALL TO NEAR OR BELOW FREEZING UNTIL AFTER SNOW
STARTS FALLING. ALL PRECIP WILL END BY MID-MORNING WITH CLEARING
SKIES AND RAPIDLY WARMING TEMPS TOMORROW AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL VARY QUITE A BIT DUE TO THE MESOSCALE NATURE OF
THE BANDING...BUT METROPLEX AIRPORTS SHOULD PROBABLY PREPARE FOR
WORST CASE SCENARIO OF 2 TO 4 INCHES OF WET SLUSHY SNOW...WITH
LESSER AMOUNTS MORE LIKELY.

AIRPORT WEATHER WARNING FOR DFW WILL BE ISSUED THIS AFTERNOON TO
ADDRESS THE SNOW POTENTIAL.

TR.92

&&

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.



&&

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$

 /




000
FXUS64 KFWD 241758
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1158 AM CST TUE FEB 24 2015

.AVIATION...
MVFR CIGS HAVE BEEN CLEARING THE METROPLEX TAF SITES FROM NW TO SE
THIS MORNING AND ALL SITES SHOULD BE VFR THIS AFTERNOON AND
EVENING. MVFR CIGS AT WACO WILL TAKE A LITTLE LONGER LIFT/SCATTER
OUT BUT WILL HAVE THEM VFR BY 22Z.

MAIN CONCERN IS OBVIOUSLY THE POTENTIAL FOR SNOW TONIGHT AND
WEDNESDAY MORNING AS STRONG UPPER LOW MOVES ACROSS. PRECIP WILL
START TO LIGHT UP THE RADARS AFTER MIDNIGHT...WITH RAIN SHOWERS
POSSIBLE BY 8Z/2AM. RAIN WILL LIKELY MIX TO AND/OR CHANGE OVER TO
SNOW BY 10Z/4AM WHEN THE COLUMN COOLS DUE TO EVAPORATION AND
DYNAMIC COOLING. MODEL GUIDANCE CONTINUES TO DISPLAY A LARGE
NORTH-SOUTH SPREAD IN THE PLACEMENT OF THE QPF WITH MOST SYNOPTIC
MODELS SUGGESTING THE HEAVIEST PRECIP WILL BE SOUTH OF METROPLEX
TAF SITES. THE HI-RES AND VARIOUS WRF MODELS ARE UNANIMOUSLY
FARTHER NORTH WITH PRECIP...LIKELY HANDLING THE MESOSCALE WRAP-
AROUND BANDING BETTER. WE WILL SIDE WITH THE LATTER GROUP OF THE
MODELS FOR THIS FORECAST...AND WILL SHOW A PERIOD OF SNOW FROM
11Z/5AM TO 15Z/9AM AT METROPLEX TAF SITES. THE POTENTIAL FOR HEAVY
SNOW REDUCING VSBY TO 1/2SM OR LESS EXISTS...BUT CONFIDENCE IS NOT
ESPECIALLY HIGH AT THIS POINT. THUS WILL SHOW A PROB30 GROUP FROM
12Z/6AM TO 14Z/8AM AS THIS WOULD BE THE MOST LIKELY WINDOW FOR
SUCH ACTIVITY. TEMPERATURES WILL BE ABOVE FREEZING THIS EVENING
AND LIKELY NOT FALL TO NEAR OR BELOW FREEZING UNTIL AFTER SNOW
STARTS FALLING. ALL PRECIP WILL END BY MID-MORNING WITH CLEARING
SKIES AND RAPIDLY WARMING TEMPS TOMORROW AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL VARY QUITE A BIT DUE TO THE MESOSCALE NATURE OF
THE BANDING...BUT METROPLEX AIRPORTS SHOULD PROBABLY PREPARE FOR
WORST CASE SCENARIO OF 2 TO 4 INCHES OF WET SLUSHY SNOW...WITH
LESSER AMOUNTS MORE LIKELY.

AIRPORT WEATHER WARNING FOR DFW WILL BE ISSUED THIS AFTERNOON TO
ADDRESS THE SNOW POTENTIAL.

TR.92

&&

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.



&&

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$

 /





000
FXUS64 KFWD 241758
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1158 AM CST TUE FEB 24 2015

.AVIATION...
MVFR CIGS HAVE BEEN CLEARING THE METROPLEX TAF SITES FROM NW TO SE
THIS MORNING AND ALL SITES SHOULD BE VFR THIS AFTERNOON AND
EVENING. MVFR CIGS AT WACO WILL TAKE A LITTLE LONGER LIFT/SCATTER
OUT BUT WILL HAVE THEM VFR BY 22Z.

MAIN CONCERN IS OBVIOUSLY THE POTENTIAL FOR SNOW TONIGHT AND
WEDNESDAY MORNING AS STRONG UPPER LOW MOVES ACROSS. PRECIP WILL
START TO LIGHT UP THE RADARS AFTER MIDNIGHT...WITH RAIN SHOWERS
POSSIBLE BY 8Z/2AM. RAIN WILL LIKELY MIX TO AND/OR CHANGE OVER TO
SNOW BY 10Z/4AM WHEN THE COLUMN COOLS DUE TO EVAPORATION AND
DYNAMIC COOLING. MODEL GUIDANCE CONTINUES TO DISPLAY A LARGE
NORTH-SOUTH SPREAD IN THE PLACEMENT OF THE QPF WITH MOST SYNOPTIC
MODELS SUGGESTING THE HEAVIEST PRECIP WILL BE SOUTH OF METROPLEX
TAF SITES. THE HI-RES AND VARIOUS WRF MODELS ARE UNANIMOUSLY
FARTHER NORTH WITH PRECIP...LIKELY HANDLING THE MESOSCALE WRAP-
AROUND BANDING BETTER. WE WILL SIDE WITH THE LATTER GROUP OF THE
MODELS FOR THIS FORECAST...AND WILL SHOW A PERIOD OF SNOW FROM
11Z/5AM TO 15Z/9AM AT METROPLEX TAF SITES. THE POTENTIAL FOR HEAVY
SNOW REDUCING VSBY TO 1/2SM OR LESS EXISTS...BUT CONFIDENCE IS NOT
ESPECIALLY HIGH AT THIS POINT. THUS WILL SHOW A PROB30 GROUP FROM
12Z/6AM TO 14Z/8AM AS THIS WOULD BE THE MOST LIKELY WINDOW FOR
SUCH ACTIVITY. TEMPERATURES WILL BE ABOVE FREEZING THIS EVENING
AND LIKELY NOT FALL TO NEAR OR BELOW FREEZING UNTIL AFTER SNOW
STARTS FALLING. ALL PRECIP WILL END BY MID-MORNING WITH CLEARING
SKIES AND RAPIDLY WARMING TEMPS TOMORROW AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL VARY QUITE A BIT DUE TO THE MESOSCALE NATURE OF
THE BANDING...BUT METROPLEX AIRPORTS SHOULD PROBABLY PREPARE FOR
WORST CASE SCENARIO OF 2 TO 4 INCHES OF WET SLUSHY SNOW...WITH
LESSER AMOUNTS MORE LIKELY.

AIRPORT WEATHER WARNING FOR DFW WILL BE ISSUED THIS AFTERNOON TO
ADDRESS THE SNOW POTENTIAL.

TR.92

&&

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.



&&

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$

 /




000
FXUS64 KFWD 241200
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
600 AM CST TUE FEB 24 2015

.AVIATION...
CIGS ARE VARYING ACROSS THE METROPLEX EARLY THIS MORNING...WITH
OVERALL IMPROVING CONDITIONS EXPECTED THROUGH THE REST OF THE
MORNING AS SLIGHTLY DRIER AIR FILTERS IN FROM THE NORTHWEST. THE
MAIN IMMEDIATE ISSUE APPEARS TO BE THE OCCASIONAL -FZDZ SHOWING UP
IN THE METRO AREA. KDAL HAS REPORTED THIS MOST OFTEN SO WE WILL GO
AHEAD AND INCLUDE A TEMPO FROM 12Z UNTIL 13Z FOR -FZDZ. WE DO NOT
EXPECT ANY ACCUMULATIONS ON ANY SURFACES.

OTHERWISE...WE SHOULD SEE AIRPORTS WHICH CURRENTLY REPORT IFR
IMPROVE TO MVFR IN THE NEAR FUTURE. ALL LOCATIONS ARE EXPECTED TO
BECOME VFR BY MIDDAY. NORTHWEST SURFACE WINDS SHOULD BECOME LIGHT
AND VARIABLE THIS AFTERNOON AS A SURFACE RIDGE MOVES DIRECTLY
OVERHEAD.

CONDITIONS SHOULD DETERIORATE AGAIN OVERNIGHT AS A LOW PRESSURE
SYSTEM OVER THE SOUTHWEST CONUS APPROACHES QUICKLY FROM THE WEST.
TEMPERATURE PROFILES SUPPORT SNOW AS THE PRIMARY FORM OF
PRECIPITATION...WHICH IS EXPECTED TO BEGIN DURING THE 06-12Z
TIME FRAME. AIRCRAFT DEICING SHOULD BECOME THE MAIN ISSUE...AS WE
COULD GET A COUPLE OF INCHES OF SNOW IN THE METROPLEX. THERE IS
THE POTENTIAL FOR HIGHER AMOUNTS DUE TO THE POSSIBILITY OF SNOW-
BANDING...HENCE THE ISSUANCE OF A WINTER STORM WATCH WHICH
INCLUDES THE METROPLEX TAF LOCATIONS. FOR NOW...WE WILL KEEP
MENTION OF SNOW IN THE LIGHT CATEGORY AND FINE TUNE THE FORECAST
TO CORRELATE WITH HEAVIER SNOW BANDS IF THEY DEVELOP NEAR ANY OF
THE METRO-AREA TAF SITES. FOR KACT...MORE OF A LIGHT RAIN/SNOW MIX
IS EXPECTED WITH LITTLE IN THE WAY OF ACCUMULATIONS. ALL ACTIVITY
SHOULD END AROUND MIDDAY WEDNESDAY AS THE SYSTEM RACES OFF TO THE
EAST.

30

&&

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.



&&

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$





000
FXUS64 KFWD 241200
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
600 AM CST TUE FEB 24 2015

.AVIATION...
CIGS ARE VARYING ACROSS THE METROPLEX EARLY THIS MORNING...WITH
OVERALL IMPROVING CONDITIONS EXPECTED THROUGH THE REST OF THE
MORNING AS SLIGHTLY DRIER AIR FILTERS IN FROM THE NORTHWEST. THE
MAIN IMMEDIATE ISSUE APPEARS TO BE THE OCCASIONAL -FZDZ SHOWING UP
IN THE METRO AREA. KDAL HAS REPORTED THIS MOST OFTEN SO WE WILL GO
AHEAD AND INCLUDE A TEMPO FROM 12Z UNTIL 13Z FOR -FZDZ. WE DO NOT
EXPECT ANY ACCUMULATIONS ON ANY SURFACES.

OTHERWISE...WE SHOULD SEE AIRPORTS WHICH CURRENTLY REPORT IFR
IMPROVE TO MVFR IN THE NEAR FUTURE. ALL LOCATIONS ARE EXPECTED TO
BECOME VFR BY MIDDAY. NORTHWEST SURFACE WINDS SHOULD BECOME LIGHT
AND VARIABLE THIS AFTERNOON AS A SURFACE RIDGE MOVES DIRECTLY
OVERHEAD.

CONDITIONS SHOULD DETERIORATE AGAIN OVERNIGHT AS A LOW PRESSURE
SYSTEM OVER THE SOUTHWEST CONUS APPROACHES QUICKLY FROM THE WEST.
TEMPERATURE PROFILES SUPPORT SNOW AS THE PRIMARY FORM OF
PRECIPITATION...WHICH IS EXPECTED TO BEGIN DURING THE 06-12Z
TIME FRAME. AIRCRAFT DEICING SHOULD BECOME THE MAIN ISSUE...AS WE
COULD GET A COUPLE OF INCHES OF SNOW IN THE METROPLEX. THERE IS
THE POTENTIAL FOR HIGHER AMOUNTS DUE TO THE POSSIBILITY OF SNOW-
BANDING...HENCE THE ISSUANCE OF A WINTER STORM WATCH WHICH
INCLUDES THE METROPLEX TAF LOCATIONS. FOR NOW...WE WILL KEEP
MENTION OF SNOW IN THE LIGHT CATEGORY AND FINE TUNE THE FORECAST
TO CORRELATE WITH HEAVIER SNOW BANDS IF THEY DEVELOP NEAR ANY OF
THE METRO-AREA TAF SITES. FOR KACT...MORE OF A LIGHT RAIN/SNOW MIX
IS EXPECTED WITH LITTLE IN THE WAY OF ACCUMULATIONS. ALL ACTIVITY
SHOULD END AROUND MIDDAY WEDNESDAY AS THE SYSTEM RACES OFF TO THE
EAST.

30

&&

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.



&&

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$




000
FXUS64 KFWD 241114
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
514 AM CST TUE FEB 24 2015

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1130 PM CST MON FEB 23 2015/
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&


.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.

&&


.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$

 /




000
FXUS64 KFWD 241114
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
514 AM CST TUE FEB 24 2015

.UPDATE...

...ANOTHER ROUND OF WINTRY PRECIPITATION IS EXPECTED TO MOVE
ACROSS NORTH CENTRAL TEXAS TONIGHT THROUGH WEDNESDAY MORNING...

EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN UPPER LEVEL
LOW PRESSURE SYSTEM CENTERED OVER THE UTAH/ARIZONA BORDER. THE
BASE OF THIS TROUGH WAS LOCATED OVER SOUTHERN CALIFORNIA EARLY
THIS MORNING...SO THE ENTIRE TROUGH WAS EXHIBITING A VERY STRONG
POSITIVE TILT. WATER VAPOR SATELLITE INDICATED THAT THERE WAS A
SMALL PIECE OF ENERGY ROTATING QUICKLY SOUTHWARD ALONG THE
SOUTHERN CALIFORNIA COAST EARLY THIS MORNING...SLIGHTLY REDUCING
THE EXTREME NATURE OF THE POSITIVE TILT TO THE TROUGH AWAY FROM
ZONAL MOVING TOWARDS NEUTRAL. THE TILT OF THIS TROUGH IS EXPECTED
TO PLAY A FAIRLY IMPORTANT ROLE IN THE MESOSCALE DYNAMICS THAT
TRANSPIRE OVER NORTH CENTRAL TEXAS TONIGHT INTO WEDNESDAY
MORNING...SO THAT IS WHY SO MUCH ATTENTION IS BEING GIVEN TO THIS
PARTICULAR ATTRIBUTE OF THE UPPER LOW/TROUGH.

TODAY...TEMPERATURES THIS MORNING ACROSS NORTH CENTRAL TEXAS WERE
IN THE MID TO UPPER 20S FOR MOST LOCATIONS. ANY WATER THAT WAS ON
THE ROADWAYS FROZE OVERNIGHT LEAVING SLICK SPOTS ON MANY AREA
ROADWAYS...BUT ESPECIALLY ON BRIDGES AND OVERPASSES. TEMPERATURES
ARE EXPECTED TO CLIMB ABOVE FREEZING TODAY ACROSS THE REGION AS
CLOUD COVER TEMPORARILY THINS OUT THIS AFTERNOON FROM NORTHWEST TO
SOUTHEAST. HOPEFULLY THIS WILL BE SUFFICIENT TO ALLOW MOST OF THE
SLEET/LIGHT ICE TO MELT BEFORE TEMPERATURES FALL BELOW FREEZING
AGAIN TONIGHT.

THE PRIMARY FOCUS OF THIS FORECAST WAS ON THE EVOLUTION OF THE
SOUTHWESTERN CONUS UPPER TROUGH MENTIONED ABOVE...AND ITS
POTENTIAL TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION ACROSS
NORTH CENTRAL TEXAS FROM TONIGHT INTO TOMORROW MORNING.

THE UPPER TROUGH IS EXPECTED TO MOVE EAST QUICKLY TODAY...BUILDING
OVER THE SOUTHERN HIGH PLAINS BY THIS EVENING. MOST 00Z MODEL
GUIDANCE INDICATED THAT THE BASE OF THIS TROUGH WILL BE MOVING
EAST SLIGHTLY FASTER THAN THE CENTER OF THE TROUGH...WITH THE END
RESULT ALLOWING THE TROUGH TO BECOME MORE NEUTRALLY TILTED AS IT
MOVES OVER NORTH TEXAS EARLY TOMORROW MORNING. HOW MUCH THIS
TROUGH TILTS TOWARDS NEUTRAL /LINED UP MORE ALONG A NORTH-SOUTH
AXIS AS OPPOSED TO AN EAST-WEST AXIS/ WILL LIKELY PLAY A BIG ROLE
IN HOW MUCH MESOSCALE ENHANCEMENT WE RECEIVE TO LIFT AND
PRECIPITATION AMOUNTS DURING THIS EVENT. THE 00Z NAM AND GFS
SOLUTIONS OFFERED UP THE WIDEST SPREAD AMONGST MODEL SOLUTIONS
WITH THE NAM FAVORING HIGHER SNOWFALL AMOUNTS FOR NORTH TEXAS AND
THE GFS FORECASTING VERY LITTLE. WITH THIS FORECAST...SIDED MORE
WITH THE NAM SOLUTION...AND WILL PROVIDE REASONS WHY BELOW;

WITH REGARDS TO 00Z GUIDANCE...THE NAM ADVERTISED THAT THE UPPER
TROUGH WAS ALMOST COMPLETELY NEUTRALLY TILTED BY THE TIME IT
MOVES OVER NORTH TEXAS WEDNESDAY MORNING. THE GFS MAINTAINED A
STRONG POSITIVE TILT AS IT MOVED THE TROUGH EAST OVER THE REGION.
ON WATER VAPOR SATELLITE IMAGERY...THE SMALL PIECE OF ENERGY
ROTATING SOUTHEAST IN THE BASE OF THE UPPER TROUGH JUST OFF THE
SOUTHERN CALIFORNIA COAST WAS SEEMINGLY NOT BEING HANDLED VERY
WELL BY THE GFS. LOOKING AT A DYNAMIC TROPOPAUSE MAP...THE GFS
INDICATED THAT THE STRATOSPHERIC INTRUSION ASSOCIATED WITH THIS
PIECE OF ENERGY WAS LOCATED AROUND 100 MILES FARTHER NORTH THAN
WHAT WATER VAPOR SATELLITE SHOWED WAS ACTUALLY HAPPENING.

IN THE BIG SCHEME OF THINGS...A 100 MILE ERROR IS ACTUALLY PRETTY
TINY COMPARED TO THE SIZE OF THE TROUGH AS A WHOLE. THE PROBLEM IS
THAT VISUALLY...THIS LITTLE PIECE OF ENERGY SEEMED TO BE
ASSOCIATED WITH A WOBBLE WITHIN THE CIRCULATION OF THE UPPER LOW
THAT WAS TRENDING THE UPPER LOW TO TILT JUST SLIGHTLY SOUTH...AWAY
FROM AN ALMOST PURELY ZONAL POSITIVE TILT EARLIER THIS MORNING. IF
THIS PIECE OF ENERGY PLAYS AN IMPORTANT ROLE IN AIDING THE UPPER
TROUGH TO ATTAIN MORE OF A NEUTRAL TILT BEFORE IT ARRIVES IN NORTH
TEXAS...THEN THIS ERROR IN THE GFS BECOMES MORE IMPORTANT. BECAUSE
THE GFS IS RUN ON A SUPERCOMPUTER...IT`S IMPOSSIBLE TO SAY FOR
SURE IF THIS ONE FEATURE IS THE MAIN REASON WHY THE GFS STAYED SO
POSITIVELY TILTED...BUT IT`S THE MOST OBVIOUS ERROR WE COULD FIND
IN TERMS OF THE DYNAMIC MODEL INITILIZATIONS ASSOCIATED WITH THIS
UPPER TROUGH. WITH THE NAM AND GFS TREATING THE EVOLUTION OF THE
UPPER TROUGH SO DIFFERENTLY...THERE HAD TO BE SOME DIFFERENCE IN
INITIALIZATION...SO HOPEFULLY THE RIGHT ONE WAS IDENTIFIED.

ONCE THE UPPER TROUGH MOVES OVER THE SOUTHERN PLAINS TONIGHT...ALL
MODELS AGREE THAT VERY STRONG LARGE SCALE FORCING FOR ASCENT WILL
BUILD OVER THE CWA. MODELS ADVERTISE 500 MB HEIGHT FALLS OF 16 TO
20 DM OVER THE CWA BY 12Z. THIS IS CONSISTENT WITH DEEP LIFT LIFT
ASSOCIATED WITH THE UPPER TROUGH BUILDING OVER THE REGION EARLY
TOMORROW MORNING. DEEP UPPER LEVEL LIFT SHOULD CONNECT WITH THE
LOWER ATMOSPHERE RESULTING IN A RESPONSE OF DEEP ISENTROPIC LIFT
OVER THE CWA. THE MAIN PROBLEM WITH THE 00Z GFS WAS THAT IT
ADVERTISED STRONG UPPER LEVEL LIFT WITHOUT MUCH OF A RESPONSE IN
LOW-LEVEL ISENTROPIC/THETA-E SURFACE FIELDS. THE NAM OFFERED UP A
SOLUTION MORE CONSISTENT WITH WHAT SHOULD DYNAMICALLY OCCUR BY
SHOWING DEEP ISENTROPIC LIFT AND LIFT ON THE 310 AND 315K THETA-E
SURFACES OUT AHEAD OF THE TROUGH. THIS RESPONSE IS IMPORTANT
BECAUSE IT ALLOW LOW-LEVEL GULF MOISTURE LOCATED SOUTHEAST OF THE
850 MB FRONT IDENTIFIED ON 00Z RAOB ANALYSIS TO GET WRAPPED UP
INTO THE SYSTEM EARLY WEDNESDAY MORNING.

AS LONG AS THIS LOW-LEVEL RESPONSE TRANSPIRES...DEEP MOISTURE
SHOULD INTERACT WITH THE STRONG LIFT AND RESULT IN FAIRLY
WIDESPREAD PRECIPITATION DEVELOPING ACROSS NORTH AND CENTRAL TEXAS
AFTER MIDNIGHT TONIGHT. ASSUMING THE NAM IS CORRECT IN WRAPPING
THIS MOISTURE UP INTO THE SYSTEM...STRONGER MESOSCALE DYNAMICS
WILL HELP SHAPE THE SYSTEM TO ALLOW FOR SOME HEAVIER PRECIPITATION
AMOUNTS AND COOLER TEMPERATURES ALOFT. WARM MOIST AIR GETTING
WRAPPED UP INTO THE MID-LEVELS OF THIS UPPER TROUGH WILL RESULT IN
STRONG FRONTOGENETIC FORCING NEAR THE COLD-CORE OF THE UPPER LOW.
DEPENDING ON STABILITY ABOVE THE FRONTOGENETIC FORCING...AREAS OF
HEAVY BANDED PRECIPITATION COULD DEVELOP.

WITH MOISTURE IN PLACE...THE NAM ADVERTISES SATURATED EPV VALUES
THAT ARE NEGATIVE THROUGH THE 700 TO 500 MB LAYER. THE NAM
INDICATES THAT VERTICAL THETA-E CONTOURS ACTUALLY FOLD ON
THEMSELVES IN THIS LAYER RESULTING IN SMALL THETA-E LAPSE RATES
ALOFT. IF MOISTURE AND FRONTOGENETIC FORCING ARE REALIZED IN THIS
ENVIRONMENT...THIS MOIST ASCENT COULD RELEASE THIS POTENTIAL
INSTABILITY ALOFT IN THE FORM OF BANDS OF CONVECTION...OR FREE
CONVECTION. THERMAL PROFILES APPEAR TO BE VERY SUPPORTIVE OF SNOW
DURING THIS EVENT...SO THE RESULT OF THIS INSTABILITY ALOFT WOULD
LIKELY BE BANDED SNOWFALL...WITH A ROGUE LIGHTNING STRIKE OR TWO
POSSIBLE. THE THETA-E LAPSE RATES WERE NOT VERY LARGE...AND ONLY
EXISTED OVER A SHALLOW LAYER...SO DO NOT THINK THUNDERSNOW WILL BE
COMMON...AND DID NOT PLACE A MENTION OF THUNDER IN THE FORECAST AS
A RESULT.

THIS IS ALL GREAT IF THE NAM VERIFIES...HOWEVER IF THE TROUGH
MOVES EAST AND MAINTAINS A STRONG POSITIVE TILT...NONE OF THESE
MESOSCALE ENHANCEMENTS/DYNAMICS ARE LIKELY GOING TO
MATTER...RESULTING IN MUCH LOWER PRECIPITATION AMOUNTS...AND A
GENERAL SHIFT TO THE SOUTH OF THE BULK OF THE PRECIPITATION. IT
WAS PRIMARILY FOR THIS REASON THAT WE LEFT THE WINTER STORM WATCH
IN EFFECT AND DID NOT HAVE THE CONFIDENCE TO UPGRADE TO A WINTER
STORM WARNING. WE NEED 4+ INCHES OF SNOW TO ISSUE A WINTER STORM
WARNING...AND CONFIDENCE IN AMOUNTS THAT HIGH IS ENTIRELY
DEPENDENT ON ALL OF THOSE MESOSCALE ENHANCEMENTS MENTIONED ABOVE.
HOPEFULLY BY THIS AFTERNOON...ENOUGH NEW DATA WILL ARRIVE THAT
WILL HELP DETERMINE WHICH SOLUTION IS MORE LIKELY TO VERIFY.

FOR OUR FORECAST...SIDED WITH THE NAM AS MENTIONED IN THE SYNOPSIS
MENTIONED IN THE 355 AM AFD. CONFIDENCE IN THIS SOLUTION WAS ONLY
AROUND 50 PERCENT...SO LEFT A WINTER STORM WATCH IN EFFECT FOR THE
DFW AREA...AND POINTS NORTHEAST. CONFIDENCE IN AT LEAST SOME LIGHT
SNOW FALLING OVER THE AREA TONIGHT REMAINS HIGH...SO WENT AHEAD
WITH A WINTER WEATHER ADVISORY SURROUNDING THE WINTER STORM WATCH.
AREAS WITHIN THE WATCH ARE MOST LIKELY TO SEE 2-4 INCH SNOWFALL
TOTALS WITH LOCALLY HIGHER AMOUNTS LIKELY IF THE NAM PANS OUT. IF
THE 00Z GFS LOOKS MORE LIKELY TO VERIFY...SNOWFALL AMOUNTS WOULD
BE UNLIKELY TO EXCEED 2 INCHES ANYWHERE...AND A WINTER WEATHER
ADVISORY WOULD BE APPROPRIATE TO UPGRADE THE WATCH AS OPPOSED TO A
WARNING. SINCE ALL OF THESE PRODUCTS HAVE BEEN ISSUED...THE 06Z
GFS DATA BECAME AVAILABLE AND ITS RAW MODEL OUTPUT IS TRENDING
TOWARDS THE NAM SOLUTION.

SUBSIDENCE BEHIND THE UPPER TROUGH IS JUST AS STRONG AS THE LIFT
OUT AHEAD OF IT...SO EXPECT SOME SUNSHINE TO RETURN TO THE REGION
FOR MOST LOCATIONS BEFORE SUNSET WEDNESDAY. THIS WILL ALLOW FOR
SOME OPPORTUNITY TO MELT WHATEVER SNOW FALLS WEDNESDAY AFTERNOON.
HOWEVER IF THE NAM VERIFIES...THERE`S VERY LITTLE CHANCE THAT IT
WILL ALL MELT WEDNESDAY NIGHT. STILL...TEMPERATURES DURING THIS
EVENT ARE EXPECTED TO REMAIN JUST BELOW FREEZING...SO THE IMPACTS
TO AREA ROADWAYS ARE NOT EXPECTED TO BE NEARLY AS BAD AS THEY
WOULD BE IF WE WERE JUST 5 DEGREES COOLER.

REMAINDER OF THE FORECAST...ANOTHER STRONG COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION ON THURSDAY. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE OVER THE REGION FROM WEST TO EAST ON FRIDAY. THIS
WILL LIKELY RESULT IN ANOTHER ROUND OF SNOW FOR NORTH TEXAS ON
FRIDAY. AT THIS TIME MOISTURE LOOKS LIMITED...SO SNOWFALL AMOUNTS
ARE EXPECTED TO REMAIN BELOW ONE INCH. WE WILL CONTINUE TO WATCH
THIS FRIDAY SYSTEM VERY CLOSELY THOUGH AS THE DETAILS OF THE
FORECAST WILL VERY LIKELY CHANGE AS MODELS RESOLVE FINER SCALE
DETAILS ASSOCIATED WITH THIS NEXT UPPER LEVEL SYSTEM.

ALTHOUGH WE ARE EXPECTED TO WARM UP THIS WEEKEND...A FAIRLY WET
PATTERN LOOKS TO REMAIN IN PLACE WITH ON AND OFF RAIN CHANCES IN
THE FORECAST THROUGH EARLY NEXT WEEK.

CAVANAUGH


&&

.AVIATION...
/ISSUED 1130 PM CST MON FEB 23 2015/
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&


.PREV DISCUSSION... /ISSUED 356 AM CST TUE FEB 24 2015/

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.

&&


.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$

 /





000
FXUS64 KFWD 240956
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
356 AM CST TUE FEB 24 2015

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&

.DISCUSSION...

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.

&&

.AVIATION...
/ISSUED 1130 PM CST MON FEB 23 2015/
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$





000
FXUS64 KFWD 240956
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
356 AM CST TUE FEB 24 2015

.SYNOPSIS...

REGARDING THE POTENTIAL FOR SNOWFALL TONIGHT INTO WEDNESDAY
MORNING...

WENT AHEAD AND EXTENDED THE WINTER STORM WATCH WEST ANOTHER ROW OF
COUNTIES SO THAT THE WATCH NOW INCLUDES LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A SHERMAN TO DECATUR TO GLEN ROSE TO CANTON LINE
FROM MIDNIGHT TONIGHT/WEDNESDAY MORNING TO NOON ON WEDNESDAY.

ISSUED A WINTER WEATHER ADVISORY TO THE WEST AND SOUTH OF THIS
WINTER STORM WATCH FOR THE SAME TIME PERIOD.

WITHIN THE WINTER STORM WATCH AREA...2-4 INCHES OF SNOWFALL IS
POSSIBLE. MOST SNOW CAN BE EXPECTED TO FALL IN THE WATCH AREA FROM
3 AM TO NOON. ALTHOUGH 2-4 INCHES OF SNOW IS TECHNICALLY BELOW
WINTER STORM WARNING CRITERIA...THERE IS A POTENTIAL FOR HIGHER
AMOUNTS WITHIN THIS BROAD AREA...SO LEFT THE WATCH IN EFFECT AS
SHORT TERM/MESOSCALE DETAILS WILL DETERMINE THE LIKELIHOOD OF
THESE LOCALLY HIGHER AMOUNTS.

WITHIN THE WINTER WEATHER ADVISORY AREA...1-2 INCHES OF SNOWFALL
IS POSSIBLE. CONFIDENCE IN LIGHTER AMOUNTS WAS HIGH ENOUGH TO GO
AHEAD WITH A WINTER WEATHER ADVISORY AT THIS TIME.

SNOW IS EXPECTED TO END FROM WEST TO EAST LATE WEDNESDAY MORNING
THROUGH EARLY WEDNESDAY AFTERNOON AS DRIER AIR WORKS INTO THE
REGION.

CONFIDENCE IN SNOWFALL ACROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING IS HIGH. CONFIDENCE IN AMOUNTS...ESPECIALLY THE
PLACEMENT OF ANY BANDED SNOWFALL/HEAVIER AMOUNTS IS FAIRLY LOW AT
THIS TIME...WHICH IS WHY A WINTER STORM WATCH IS STILL IN EFFECT.

ONCE THE UPPER TROUGH STARTS MOVING AWAY FROM THE SOUTHWESTERN
CONUS...WE WILL HAVE A MUCH BETTER IDEA OF WHETHER ANY PART OF THE
WATCH NEEDS TO BE UPGRADED TO A WARNING OR NOT. IT IS POSSIBLE THE
ENTIRE AREA MAY BE COVERED BY AN ADVISORY...BUT THE MORNING
WEATHER BALLOON DATA COMBINED WITH THE 12Z MODEL DATA WILL GO A
LONG WAY IN ADDING CONFIDENCE TO THAT DECISION.

TEMPERATURES ARE STILL EXPECTED TO CLIMB ABOVE FREEZING WEDNESDAY
AFTERNOON AS TEMPERATURES WILL PROBABLY ONLY FALL INTO THE 29-32
DEGREE RANGE WHILE SNOW IS FALLING. SNOW MELT SHOULD OCCUR FOR
MANY LOCATIONS WEDNESDAY AFTERNOON.

ANOTHER CHANCE OF SNOW IS IN THE FORECAST FOR FRIDAY...BUT WILL
ADDRESS THAT WITH THE UPDATED FORECAST DISCUSSION LATER THIS
MORNING

CAVANAUGH

&&

.DISCUSSION...

WILL ISSUE A MORE DETAILED DISCUSSION LATER THIS MORNING.

&&

.AVIATION...
/ISSUED 1130 PM CST MON FEB 23 2015/
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79


&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  38  30  46  33  43 /  10  80  80  10  10
WACO, TX              38  31  51  31  48 /  10  70  70  10   5
PARIS, TX             36  27  40  29  40 /  10  60  80  10  10
DENTON, TX            36  27  47  30  42 /  10  80  70  10  10
MCKINNEY, TX          37  27  42  29  41 /  10  80  80  10  10
DALLAS, TX            39  31  47  33  43 /  10  80  80  10  10
TERRELL, TX           38  29  43  32  42 /  10  80  80  10  10
CORSICANA, TX         39  31  44  33  46 /  10  60  80  10   5
TEMPLE, TX            38  31  53  33  50 /  10  60  60  10   5
MINERAL WELLS, TX     37  28  52  31  44 /  10  80  70  10  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR TXZ093>095-102>107-117>123-131>134.

WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
WEDNESDAY FOR TXZ091-092-100-101-115-116-129-130-135-141>148-157-
159-161.


&&

$$




000
FXUS64 KFWD 240530
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1130 PM CST MON FEB 23 2015

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79

&&

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82




000
FXUS64 KFWD 240530
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1130 PM CST MON FEB 23 2015

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79

&&

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82





000
FXUS64 KFWD 240530
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1130 PM CST MON FEB 23 2015

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79

&&

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82




000
FXUS64 KFWD 240530
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1130 PM CST MON FEB 23 2015

.AVIATION...
MVFR CEILINGS WILL PREVAIL AT THE METROPLEX TAF SITES OVERNIGHT
AND SHOULD LIFT TO VFR HEIGHTS AROUND MIDDAY BEFORE SCATTERING
OUT. WACO WILL SEE IFR CEILINGS OVERNIGHT BUT WILL ALSO LIFT AND
SCATTER DURING THE MORNING. VFR CONDITIONS ARE EXPECTED AT ALL
SITES TUESDAY AFTERNOON. A NORTH WIND AROUND 10 KNOTS OVERNIGHT
WILL TURN MORE NORTHWEST DURING THE DAY TUESDAY AND DECREASE A
BIT.

FOR THE EXTENDED PORTION OF THE DFW TAF WILL INCLUDE THE MENTION
OF LIGHT SNOW JUST BEFORE 12Z WEDNESDAY.

79

&&

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82





000
FXUS64 KFWD 240341 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
941 PM CST MON FEB 23 2015

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.AVIATION...
/ISSUED 551 PM CST MON FEB 23 2015/
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&

.AVIATION...
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&



.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82





000
FXUS64 KFWD 240341 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
941 PM CST MON FEB 23 2015

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.AVIATION...
/ISSUED 551 PM CST MON FEB 23 2015/
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&

.AVIATION...
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&



.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82




000
FXUS64 KFWD 240341 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
941 PM CST MON FEB 23 2015

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.AVIATION...
/ISSUED 551 PM CST MON FEB 23 2015/
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&

.AVIATION...
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&



.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82





000
FXUS64 KFWD 240341 AAB
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
941 PM CST MON FEB 23 2015

.UPDATE...
COLD AND ICY CONDITIONS CONTINUE TO GRIP A LARGE PART OF NORTH AND
CENTRAL TEXAS TONIGHT. TEMPERATURES AT 9 PM RANGED FROM 24 DEGREES
TO 31 DEGREES AND WILL FALL ABOUT ANOTHER 3-4 DEGREES THROUGH THE
NIGHT...BUT OVERCAST SKIES AND A LACK OF COLD AIR ADVECTION WILL
KEEP THEM FROM FALLING MUCH FURTHER THAN A FEW DEGREES.

THE MEASURABLE PRECIPITATION HAS ENDED ACROSS THE REGION AND WE
EXPECT THE REMAINDER OF THE NIGHT TO BE FAIRLY DRY. PATCHY AREAS
OF FREEZING DRIZZLE WILL BE POSSIBLE THROUGH THE NIGHT IF/WHEN ANY
SMALL DISTURBANCES MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW
ALOFT. AT THE CURRENT TIME...ONE SMALL DISTURBANCE MAY BE
APPROACHING OUR CENTRAL TEXAS ZONES AS LIGHT REFLECTIVITY
CONTINUES TO SLOWLY EXPAND IN THE HILL COUNTRY. BY DAYBREAK...A
FEW SLEET OR SNOW SHOWERS MAY APPROACH OUR SOUTHWEST COUNTIES AND
WILL KEEP A LOW POP FOR A SLEET/SNOW MIX GENERALLY WEST OF I-35
AND SOUTH OF I-20 AFTER MIDNIGHT THROUGH 6 AM. OTHERWISE...WILL
MAINTAIN A MENTION OF PATCHY FREEZING DRIZZLE EVERYWHERE.

WITH NO MEASURABLE PRECIPITATION EXPECTED...HAVE CANCELLED THE
WINTER WEATHER ADVISORY ACROSS OUR SOUTHERN ZONES. HOWEVER...
SCATTERED ICY ROAD CONDITIONS WILL STILL CONTINUE IN THE PREVIOUS
ADVISORY LOCATION AND HAZARDOUS TRAVEL CONDITIONS DUE TO ICY ROADS
WILL CONTINUE NORTH OF THE ADVISORY AREA WHERE GREATER AMOUNTS OF
SLEET FELL TODAY. THERE WAS SOME MELTING OF THE SLEET ON HIGHLY
TRAVELED ROADS TODAY...BUT AS SOON AS THE SUN WENT DOWN...MOST OF
THE MELTED SLEET/ICE BEGAN TO REFREEZE AND TRAVEL CONDITIONS
TONIGHT AND TOMORROW MORNING MAY BE MORE HAZARDOUS THAN THEY WERE
TODAY. WILL EXPAND THE SPS ACROSS ALL OF NORTH TEXAS HIGHLIGHTING
THE ICY ROAD CONDITIONS OVERNIGHT AND TOMORROW MORNING.

ONE FINAL THING THAT MAY DEVELOP TONIGHT IS SOME PATCHY FREEZING
FOG. DID NOT INCLUDE A MENTION OF THIS IN THE ZONE PRODUCTS SINCE
THE FREEZING DRIZZLE WAS ALREADY MENTIONED BUT FREEZING FOG COULD
ALSO DEPOSIT A THIN LAYER OF ICE ON SURFACES AND ROADWAYS.

REGARDING THE SNOW POTENTIAL TUESDAY NIGHT AND WEDNESDAY AM...THE
NAM IS CURRENTLY THE ONLY NEW 00Z MODEL DATA THAT HAS ARRIVED AND
IT CONTINUES TO BE AGGRESSIVE WITH THE SNOW POTENTIAL. WILL NOT
MAKE ANY CHANGES AT THIS TIME UNTIL WE SEE MORE 00Z DATA BUT IF
THE NAM IS THE PREFERRED MODEL...THE WATCH MAY HAVE TO BE EXPANDED
FURTHER WEST AND/OR SOUTH.

82/JLD

&&

.AVIATION...
/ISSUED 551 PM CST MON FEB 23 2015/
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&

.AVIATION...
LOW MVFR TO IFR CEILINGS BETWEEN 700 AND 1200 FT WILL PREVAIL AT
ALL NORTH TEXAS TAF SITES THROUGH TUESDAY MORNING WITH
VISIBILITIES GENERALLY BETWEEN 3 AND 6 MILES. SOME INTERMITTENT
VERY LIGHT FREEZING DRIZZLE IS POSSIBLE THROUGH THE NIGHT DUE TO
SATURATION IN THE LOW LEVELS OF THE ATMOSPHERE. SINCE LIFT WILL BE
WEAK...THE FREEZING DRIZZLE SHOULD BE VERY LIGHT AND NOT HAVE MUCH
OF AN IMPACT. LOW CEILINGS SHOULD LIFT AND SCATTER TUESDAY
AFTERNOON AS SOME DRY AIR MIXES DOWN.

A NORTH TO NORTHWEST WIND WILL PREVAIL AT SPEEDS BETWEEN 7 AND 13
KNOTS TONIGHT AND LESS THAN 10 KNOTS ON TUESDAY.

79


&&



.PREV DISCUSSION... /ISSUED 347 PM CST MON FEB 23 2015/

...MORE WINTRY WEATHER POSSIBLE THROUGH EARLY WEDNESDAY...

.LATEST CHANGES TO CURRENT WARNINGS/ADVISORIES...

CURRENT WINTER STORM WARNING WILL BE CANCELLED AND REPLACED WITH A
SPECIAL WEATHER STATEMENT TO ADDRESS ONGOING ICE ON AREA ROADS AND
MINOR FREEZING DRIZZLE THROUGH TONIGHT.

CURRENT WINTER WEATHER ADVISORY WILL CONTINUE THROUGH THE
OVERNIGHT HOURS FOR BETTER CHANCES OF LIGHT FREEZING DRIZZLE OR
SOME LIGHT SLEET.

A NEW WINTER STORM WATCH WILL BE ISSUED FOR LATE TUESDAY NIGHT
INTO WEDNESDAY FOR POTENTIAL ACCUMULATING SNOW WITH PASSAGE OF
STRONG UPPER TROUGH.

.TECHNICAL DISCUSSION...

MOST OF THE HEAVY SLEET HAS NOW MOVED OUT OF NORTH TEXAS WITH ONLY
LIGHT SLEET OR SOME SNOW GRAINS SCATTERED THROUGHOUT THE REGION.
THIS ACTIVITY IS EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS
ALTHOUGH NO ADDITIONAL SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
WATER VAPOR IMAGERY SHOWS SEVERAL SMALL RIPPLES INDICATIVE OF WEAK
FORCING ALOFT WHICH WILL LIKELY MOVE OUT OF THE FAR SOUTHWEST U.S.
AND INTO WEST TEXAS TONIGHT. THERE MAY BE ENOUGH ASCENT FOR A FEW
MORE POCKETS OF SLEET LATE TONIGHT...PARTICULARLY ACROSS THE
SOUTHERN HALF OF THE CWA. IN ADDITION...SOME LIGHT FREEZING
DRIZZLE WILL BE POSSIBLE THROUGH THE OVERNIGHT. WE WILL KEEP THE
WINTER WEATHER ADVISORY OUT FOR THE SOUTHERN HALF OF THE CWA UNTIL
TOMORROW MORNING.

FARTHER NORTH...THE WINTER STORM WARNING WILL BE CANCELLED
ALTHOUGH THERE WILL STILL BE PLENTY OF TRAVEL PROBLEMS AS COPIOUS
AMOUNTS OF SLUSH AND ICE ARE EXPECTED TO REMAIN ON AREA ROADS.
THIS WILL BE PARTICULARLY TRUE OF BRIDGES AND ROADS THAT HAVE NOT
BEEN TREATED. TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOW TO
MID 20S IN AREAS WHERE SIGNIFICANT SLEET OCCURRED...SO LITTLE IN
THE WAY OF MELT IS EXPECTED THROUGH TUESDAY MORNING. A SPECIAL
WEATHER STATEMENT WILL BE ISSUED TO ADDRESS THESE CONCERNS.

TUESDAY WILL BE ANOTHER COLD DAY. DEEP MOISTURE WILL REMAIN IN
PLACE SO CLOUD COVER WILL LINGER THROUGHOUT THE DAY. TEMPERATURES
ARE EXPECTED TO WARM TO FREEZING OR ABOVE BY MIDDAY ACROSS MOST OF
THE REGION...SO MUCH OF THE SLEET ACCUMULATION WILL MELT ON ROADS
ALTHOUGH THERE WILL STILL LIKELY BE SLICK SPOTS THROUGHOUT THE
DAY. TUESDAY SHOULD REMAIN DRY ACROSS NORTH TEXAS.

ATTENTION GETS TURNED TO TUESDAY NIGHT AND WEDNESDAY WHEN THE MAIN
UPPER LOW ACROSS CALIFORNIA COMES RACING ACROSS NORTH TEXAS.
THIS IS A POWERFUL COLD CORE UPPER LOW THAT LOOKS LIKE IT WILL
TRACK DIRECTLY ACROSS THE CWA. THIS TRACK IS IMPORTANT BECAUSE
VERY STRONG DYNAMIC LIFT WILL BE TIED VERY CLOSE TO THE CENTER OF
THE LOW. THIS FORCING WILL COOL THE THERMAL PROFILE AS IT COMES
ACROSS AND WILL LIKELY RESULT IN ONE OR MORE BANDS OF MODERATE TO
HEAVY SNOW. ANALYSIS OF 750-650MB TEMPERATURE AND THETA-E REVEALS
A TROWAL THAT SETS UP ACROSS OUR EAST-CENTRAL AND NORTHEAST
COUNTIES LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS WARM
CONVEYOR BELT FEATURE WILL FORCE A RICH SUPPLY OF MOISTURE UPWARD
INTO VERY COLD AIR. WITH THERMAL PROFILES COLD ENOUGH FOR
SNOW...MODEL QPF AMOUNTS ARE SUFFICIENTLY HIGH TO SUGGEST THAT
SOME OF THE SNOW COULD BE HEAVY. THIS TYPE OF UPPER LOW IS ONE
THAT CLIMATOLOGICALLY PRODUCES SNOW ACROSS SOME PART OF NORTH
TEXAS. A RICH MOISTURE SUPPLY IS IN PLACE AND IS NOT EXPECTED TO
BE SCOURED OUT IN ANY WAY SO THERE COULD BE SOME BANDS OF LOCALLY
HEAVY SNOW.

CONCERNS...

IF THE TRACK IS TOO FAR SOUTH...THEN TEMPERATURES MAY BE TOO WARM
FOR SNOWFALL AS MOST OF THE PRECIPITATION WOULD BE FARTHER SOUTH.
AT THIS TIME...THERE IS MODERATE CONFIDENCE IN THE TRACK OF THE
UPPER LOW.

BANDED SNOW NEAR THE CORE OF THE LOW. WHILE WE WILL HAVE MUCH OF
OUR NORTHEAST CWA UNDER A NEW WINTER STORM WATCH...IT IS LIKELY
THAT NOT ALL OF THESE AREAS WILL BE IMPACTED BY HEAVY SNOWFALL
AMOUNTS. THESE TYPES OF LOWS TYPICALLY PRODUCE BANDS OF LOCALLY
HEAVY SNOW...SO SOME AREAS COULD PICK UP SUBSTANTIALLY MORE THAN
OTHERS JUST MILES AWAY.

POTENTIAL FOR CONVECTIVE SNOW. SIMILAR TO LAST NIGHTS SLEET
EVENT...THERE WILL BE AVAILABLE INSTABILITY SO IT IS POSSIBLE TO
HAVE CONVECTIVE SNOW BANDS SET UP. CONVECTIVE SNOW WOULD ACCUMULATE
VERY QUICKLY.

CONFIDENCE...

CONFIDENCE IS INCREASING IN AT LEAST ONE SUBSTANTIAL BAND OF
SNOWFALL ACCUMULATION ACROSS PARTS OF NORTH TEXAS LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. WE HAVE HIGHLIGHTED OUR HIGHEST
CONFIDENCE IN THE NEW WINTER STORM WATCH FROM AREAS IN THE
METROPLEX NORTHEAST TO PARIS.

THIS SYSTEM WILL BE VERY FAST MOVING. AND SHOULD EXIT THE AREA BY
MIDDAY WEDNESDAY. STRONG WARMING WILL OCCUR RIGHT BEHIND THIS
SYSTEM AND SKIES MAY ACTUALLY BECOME SUNNY BY AFTERNOON WHICH
WOULD MELT ANY ACCUMULATED SNOWS. ANOTHER COLD FRONT WILL MOVE
THROUGH ON THURSDAY WITH ADDITIONAL LIGHT PRECIP CHANCES THROUGH
THE WEEKEND.

DUNN



&&


.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  24  38  30  47  32 /  10  10  70  80   5
WACO, TX              24  40  32  49  31 /  20  10  70  70   5
PARIS, TX             24  37  28  42  29 /  10  10  50  80   5
DENTON, TX            21  38  26  46  29 /  10  10  60  70   5
MCKINNEY, TX          24  37  26  44  29 /  10  10  60  80   5
DALLAS, TX            25  39  31  46  32 /  10  10  70  80   5
TERRELL, TX           25  37  29  42  30 /  10  10  70  80   5
CORSICANA, TX         26  39  33  44  31 /  10  10  70  80   5
TEMPLE, TX            26  40  33  52  32 /  20  10  70  50   5
MINERAL WELLS, TX     21  38  27  52  31 /  10  10  60  50   5

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING FOR TXZ093>095-103>107-118>123-133-134.


&&

$$

79/82




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