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000
FXUS64 KHUN 050549
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1149 PM CST WED MAR 4 2015

.UPDATE...
FOR 06Z TAFS

&&

.DISCUSSION...
/ISSUED 944 PM CST WED MAR 4 2015/
THE COLD FRONT HAS NOW PUSHED THROUGH THE ENTIRE AREA. MANY LOCATIONS
SAW TEMPS PLUMMET 20 OR MORE DEGREES IN LESS THAN AN HOUR WITH THIS
FRONT. OBS AROUND THE TENNESSEE VALLEY ARE IN THE LOW TO MID 40S
WITH THE EXCEPTION BEING NW ALABAMA AND SOUTHERN MIDDLE TENNESSEE
WHERE TEMPS ARE IN THE MID 30S. BASED ON TEMPERATURE
TRENDS...UPSTREAM OBSERVATIONS AT OR BELOW FREEZING...AND LATEST
HRRR/RAP HOURLY TEMPERATURE FORECASTS...DECIDED TO START THE WINTER
STORM WARNING AT MIDNIGHT FOR FAR NW ALABAMA AND S MIDDLE TN. THE
WINTER STORM WARNING STARTS AT 3AM FOR THE REST OF NORTHERN ALABAMA.

THE MOST RECENT UAH UPPER AIR PROFILER MATCHES UP WELL WITH THE 03Z
RAP FORECAST SOUNDINGS FOR THE HUNTSVILLE AREA. SIGNIFICANT WARM NOSE
IN THE 850MB LAYER OF +10C WILL ALLOW FOR ANY PRECIPITATION THAT IS
FALLING TO MELT COMPLETELY. WHEN SURFACE TEMPERATURES BEGIN TO DROP
BELOW FREEZING THIS WILL TRANSITION OVER TO FREEZING RAIN. BASED ON
SOUNDING DATA THE WARM NOSE BEGINS TO LIFT AND COOL BETWEEN 10-15Z
THURSDAY MORNING. DURING THIS TIME FRAME THERE WILL BE ENOUGH COLD
AIR NEAR THE SURFACE THAT ANYTHING FALLING WILL LIKELY TRANSITION
OVER TO A MOSTLY SLEET/LIGHT SNOW MIX. LIGHT SNOW IS THEN POSSIBLE
AROUND NOON AND WILL GRADUALLY TAPER OFF BY EARLY AFTERNOON.

ICE ACCUMULATIONS OF UP TO 0.30 INCHES REMAINS POSSIBLE FOR THE
ENTIRE TENNESSEE VALLEY REGION. SNOW AND SLEET ACCUMULATIONS UP TO A
HALF OF AN INCH POSSIBLE AS WELL.

STUMPF

&&

.AVIATION...
FOR 06Z TAFS...
05Z OBS SHOW TEMPERATURES NEAR FREEZING AT KMSL. EXPECT PRECIP TO
BEGIN TO TRANSITION OVER TO FREEZING RAIN WITH SOME SLEET MIXED IN AT
KMSL. FOR KHSV THIS WILL BE DELAYED UNTIL BETWEEN 09-12Z. BETWEEN
14-16Z THURSDAY MORNING TEMPERATURES BECOME COLD ENOUGH FOR A
TRANSITION OVER TO A -IP/SN MIX FOR BOTH TERMINALS AND UP TO A HALF
AN INCH OF SLEET ACCUMULATION IS POSSIBLE.

CIGS ARE EXPECTED TO HOVER AROUND 1000-1500FT THROUGH THE MORNING
HOURS AND MAY OCCASIONALLY LOWER DOWN TO AROUND 700-800FT DURING
HEAVIER PRECIPITATION. GUSTY N/NW WINDS ARE FORECAST TO CONTINUE
THROUGH THE ENTIRE TAF PERIOD WITH GUSTS BETWEEN 20-25KTS POSSIBLE.

ALL PRECIP SHOULD BEGIN TO TAPER OFF AFTER 18Z AND CIGS SHOULD BEGIN
TO INCREASE TO AROUND 2KFT...THEN BECOME VFR BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ004>010-
     016.

     WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR ALZ001>003.

TN...WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 050549
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1149 PM CST WED MAR 4 2015

.UPDATE...
FOR 06Z TAFS

&&

.DISCUSSION...
/ISSUED 944 PM CST WED MAR 4 2015/
THE COLD FRONT HAS NOW PUSHED THROUGH THE ENTIRE AREA. MANY LOCATIONS
SAW TEMPS PLUMMET 20 OR MORE DEGREES IN LESS THAN AN HOUR WITH THIS
FRONT. OBS AROUND THE TENNESSEE VALLEY ARE IN THE LOW TO MID 40S
WITH THE EXCEPTION BEING NW ALABAMA AND SOUTHERN MIDDLE TENNESSEE
WHERE TEMPS ARE IN THE MID 30S. BASED ON TEMPERATURE
TRENDS...UPSTREAM OBSERVATIONS AT OR BELOW FREEZING...AND LATEST
HRRR/RAP HOURLY TEMPERATURE FORECASTS...DECIDED TO START THE WINTER
STORM WARNING AT MIDNIGHT FOR FAR NW ALABAMA AND S MIDDLE TN. THE
WINTER STORM WARNING STARTS AT 3AM FOR THE REST OF NORTHERN ALABAMA.

THE MOST RECENT UAH UPPER AIR PROFILER MATCHES UP WELL WITH THE 03Z
RAP FORECAST SOUNDINGS FOR THE HUNTSVILLE AREA. SIGNIFICANT WARM NOSE
IN THE 850MB LAYER OF +10C WILL ALLOW FOR ANY PRECIPITATION THAT IS
FALLING TO MELT COMPLETELY. WHEN SURFACE TEMPERATURES BEGIN TO DROP
BELOW FREEZING THIS WILL TRANSITION OVER TO FREEZING RAIN. BASED ON
SOUNDING DATA THE WARM NOSE BEGINS TO LIFT AND COOL BETWEEN 10-15Z
THURSDAY MORNING. DURING THIS TIME FRAME THERE WILL BE ENOUGH COLD
AIR NEAR THE SURFACE THAT ANYTHING FALLING WILL LIKELY TRANSITION
OVER TO A MOSTLY SLEET/LIGHT SNOW MIX. LIGHT SNOW IS THEN POSSIBLE
AROUND NOON AND WILL GRADUALLY TAPER OFF BY EARLY AFTERNOON.

ICE ACCUMULATIONS OF UP TO 0.30 INCHES REMAINS POSSIBLE FOR THE
ENTIRE TENNESSEE VALLEY REGION. SNOW AND SLEET ACCUMULATIONS UP TO A
HALF OF AN INCH POSSIBLE AS WELL.

STUMPF

&&

.AVIATION...
FOR 06Z TAFS...
05Z OBS SHOW TEMPERATURES NEAR FREEZING AT KMSL. EXPECT PRECIP TO
BEGIN TO TRANSITION OVER TO FREEZING RAIN WITH SOME SLEET MIXED IN AT
KMSL. FOR KHSV THIS WILL BE DELAYED UNTIL BETWEEN 09-12Z. BETWEEN
14-16Z THURSDAY MORNING TEMPERATURES BECOME COLD ENOUGH FOR A
TRANSITION OVER TO A -IP/SN MIX FOR BOTH TERMINALS AND UP TO A HALF
AN INCH OF SLEET ACCUMULATION IS POSSIBLE.

CIGS ARE EXPECTED TO HOVER AROUND 1000-1500FT THROUGH THE MORNING
HOURS AND MAY OCCASIONALLY LOWER DOWN TO AROUND 700-800FT DURING
HEAVIER PRECIPITATION. GUSTY N/NW WINDS ARE FORECAST TO CONTINUE
THROUGH THE ENTIRE TAF PERIOD WITH GUSTS BETWEEN 20-25KTS POSSIBLE.

ALL PRECIP SHOULD BEGIN TO TAPER OFF AFTER 18Z AND CIGS SHOULD BEGIN
TO INCREASE TO AROUND 2KFT...THEN BECOME VFR BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ004>010-
     016.

     WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR ALZ001>003.

TN...WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 050344
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
944 PM CST WED MAR 4 2015

.UPDATE...
UPDATED TEMPERATURE TRENDS THIS EVENING.

&&

.DISCUSSION...
THE COLD FRONT HAS NOW PUSHED THROUGH THE ENTIRE AREA. MANY LOCATIONS
SAW TEMPS PLUMMET 20 OR MORE DEGREES IN LESS THAN AN HOUR WITH THIS
FRONT. OBS AROUND THE TENNESSEE VALLEY ARE IN THE LOW TO MID 40S
WITH THE EXCEPTION BEING NW ALABAMA AND SOUTHERN MIDDLE TENNESSEE
WHERE TEMPS ARE IN THE MID 30S. BASED ON TEMPERATURE
TRENDS...UPSTREAM OBSERVATIONS AT OR BELOW FREEZING...AND LATEST
HRRR/RAP HOURLY TEMPERATURE FORECASTS...DECIDED TO START THE WINTER
STORM WARNING AT MIDNIGHT FOR FAR NW ALABAMA AND S MIDDLE TN. THE
WINTER STORM WARNING STARTS AT 3AM FOR THE REST OF NORTHERN ALABAMA.

THE MOST RECENT UAH UPPER AIR PROFILER MATCHES UP WELL WITH THE 03Z
RAP FORECAST SOUNDINGS FOR THE HUNTSVILLE AREA. SIGNIFICANT WARM NOSE
IN THE 850MB LAYER OF +10C WILL ALLOW FOR ANY PRECIPITATION THAT IS
FALLING TO MELT COMPLETELY. WHEN SURFACE TEMPERATURES BEGIN TO DROP
BELOW FREEZING THIS WILL TRANSITION OVER TO FREEZING RAIN. BASED ON
SOUNDING DATA THE WARM NOSE BEGINS TO LIFT AND COOL BETWEEN 10-15Z
THURSDAY MORNING. DURING THIS TIME FRAME THERE WILL BE ENOUGH COLD
AIR NEAR THE SURFACE THAT ANYTHING FALLING WILL LIKELY TRANSITION
OVER TO A MOSTLY SLEET/LIGHT SNOW MIX. LIGHT SNOW IS THEN POSSIBLE
AROUND NOON AND WILL GRADUALLY TAPER OFF BY EARLY AFTERNOON.

ICE ACCUMULATIONS OF UP TO 0.30 INCHES REMAINS POSSIBLE FOR THE
ENTIRE TENNESSEE VALLEY REGION. SNOW AND SLEET ACCUMULATIONS UP TO A
HALF OF AN INCH POSSIBLE AS WELL.

STUMPF

&&

.AVIATION...
/ISSUED 524 PM CST WED MAR 4 2015/
FOR 00Z TAFS...
COLD FRONT HAS NOW MOVED THROUGH BOTH TERMINALS AS OF 23Z WITH WINDS
SHIFTING N/NW AND GUSTING 20-25KTS. LIGHT TO MODERATE RAIN SHOWERS
WILL CONTINUE THROUGH 09Z...THEN TRANSITION TO FREEZING RAIN BETWEEN
9-11Z. THE TIMING OF THIS TRANSITION MAY CHANGE..MAINLY DUE TO HOW
QUICKLY BELOW FREEZING AIR ARRIVES INTO THE AREA. THE TEMPERATURES
BECOME COLD ENOUGH BY MID MORNING THURSDAY FOR A CHANGE OVER TO
-IP/SN WITH A HALF AN INCH OF SLEET ACCUMULATION POSSIBLE. CIGS ARE
EXPECTED TO BE BETWEEN 1000-1500FT THROUGH THE PERIOD AND MAY DURING
THE HEAVIER PERIODS OF RAIN DROP DOWN TO 700FT WITH VISIBILITIES
DROPPING BELOW 2 MILES. NW WINDS REMAIN GUSTY BETWEEN 20-25KTS
THROUGH THE TAF PERIOD. DRIER AIR BEGINS TO PUSH INTO THE AREA
THURSDAY AFTERNOON WITH CIGS INCREASING TO BETWEEN 1500-2000FT...THEN
EVENTUALLY CLEARING OUT BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ004>010-
     016.

     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST THURSDAY FOR
     ALZ001>003.

TN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST THURSDAY FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 050344
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
944 PM CST WED MAR 4 2015

.UPDATE...
UPDATED TEMPERATURE TRENDS THIS EVENING.

&&

.DISCUSSION...
THE COLD FRONT HAS NOW PUSHED THROUGH THE ENTIRE AREA. MANY LOCATIONS
SAW TEMPS PLUMMET 20 OR MORE DEGREES IN LESS THAN AN HOUR WITH THIS
FRONT. OBS AROUND THE TENNESSEE VALLEY ARE IN THE LOW TO MID 40S
WITH THE EXCEPTION BEING NW ALABAMA AND SOUTHERN MIDDLE TENNESSEE
WHERE TEMPS ARE IN THE MID 30S. BASED ON TEMPERATURE
TRENDS...UPSTREAM OBSERVATIONS AT OR BELOW FREEZING...AND LATEST
HRRR/RAP HOURLY TEMPERATURE FORECASTS...DECIDED TO START THE WINTER
STORM WARNING AT MIDNIGHT FOR FAR NW ALABAMA AND S MIDDLE TN. THE
WINTER STORM WARNING STARTS AT 3AM FOR THE REST OF NORTHERN ALABAMA.

THE MOST RECENT UAH UPPER AIR PROFILER MATCHES UP WELL WITH THE 03Z
RAP FORECAST SOUNDINGS FOR THE HUNTSVILLE AREA. SIGNIFICANT WARM NOSE
IN THE 850MB LAYER OF +10C WILL ALLOW FOR ANY PRECIPITATION THAT IS
FALLING TO MELT COMPLETELY. WHEN SURFACE TEMPERATURES BEGIN TO DROP
BELOW FREEZING THIS WILL TRANSITION OVER TO FREEZING RAIN. BASED ON
SOUNDING DATA THE WARM NOSE BEGINS TO LIFT AND COOL BETWEEN 10-15Z
THURSDAY MORNING. DURING THIS TIME FRAME THERE WILL BE ENOUGH COLD
AIR NEAR THE SURFACE THAT ANYTHING FALLING WILL LIKELY TRANSITION
OVER TO A MOSTLY SLEET/LIGHT SNOW MIX. LIGHT SNOW IS THEN POSSIBLE
AROUND NOON AND WILL GRADUALLY TAPER OFF BY EARLY AFTERNOON.

ICE ACCUMULATIONS OF UP TO 0.30 INCHES REMAINS POSSIBLE FOR THE
ENTIRE TENNESSEE VALLEY REGION. SNOW AND SLEET ACCUMULATIONS UP TO A
HALF OF AN INCH POSSIBLE AS WELL.

STUMPF

&&

.AVIATION...
/ISSUED 524 PM CST WED MAR 4 2015/
FOR 00Z TAFS...
COLD FRONT HAS NOW MOVED THROUGH BOTH TERMINALS AS OF 23Z WITH WINDS
SHIFTING N/NW AND GUSTING 20-25KTS. LIGHT TO MODERATE RAIN SHOWERS
WILL CONTINUE THROUGH 09Z...THEN TRANSITION TO FREEZING RAIN BETWEEN
9-11Z. THE TIMING OF THIS TRANSITION MAY CHANGE..MAINLY DUE TO HOW
QUICKLY BELOW FREEZING AIR ARRIVES INTO THE AREA. THE TEMPERATURES
BECOME COLD ENOUGH BY MID MORNING THURSDAY FOR A CHANGE OVER TO
-IP/SN WITH A HALF AN INCH OF SLEET ACCUMULATION POSSIBLE. CIGS ARE
EXPECTED TO BE BETWEEN 1000-1500FT THROUGH THE PERIOD AND MAY DURING
THE HEAVIER PERIODS OF RAIN DROP DOWN TO 700FT WITH VISIBILITIES
DROPPING BELOW 2 MILES. NW WINDS REMAIN GUSTY BETWEEN 20-25KTS
THROUGH THE TAF PERIOD. DRIER AIR BEGINS TO PUSH INTO THE AREA
THURSDAY AFTERNOON WITH CIGS INCREASING TO BETWEEN 1500-2000FT...THEN
EVENTUALLY CLEARING OUT BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ004>010-
     016.

     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST THURSDAY FOR
     ALZ001>003.

TN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST THURSDAY FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 042324
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
524 PM CST WED MAR 4 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 257 PM CST WED MAR 4 2015/
THE 21Z SURFACE ANALYSIS INDICATED THAT THE COLD FRONT WAS EXTENDING
NORTHEAST FROM NEAR CORINTH MISSISSIPPI AND BARELY INTO THE FORECAST
AREA IN NORTHWEST ALABAMA NEAR FLORENCE...TO NEAR FAYETTEVILLE
TENNESSEE. A LARGE AREA OF MAINLY LIGHT TO MODERATE RAIN WAS MAINLY
ALONG AND BEHIND THE COLD FRONT ACROSS MUCH OF NORTHERN MISSISSIPPI
AND THROUGHOUT WEST AND MIDDLE TENNESSEE.

EXPECT SHOWERS/EMBEDDED STORMS TO CONTINUE TO INCREASE IN COVERAGE
ACROSS THE FORECAST AREA INTO THE EARLY-MID EVENING AS THE COLD FRONT
MOVES THROUGH THE FORECAST AREA. THE SHORT TERM MODELS ARE FAIRLY
SIMILAR INVOLVING HAVING THE COLD FRONT MOVE THROUGH THE AREA BY
AROUND 03Z TONIGHT. A WINTER STORM WARNING REMAINS IN EFFECT FOR THE
FORECAST AREA FROM 09Z-21Z ON THURSDAY. STRONG COLD ADVECTION WILL
IMMEDIATELY FILTER SOUTHEAST INTO THE FORECAST AREA BEHIND THE COLD
FRONT THROUGH THE OVERNIGHT HOURS. HAVE SLIGHTLY ADJUSTED THE TIMING
FORWARD OF THE EXPECTED TRANSITION FROM RAIN TO FREEZING RAIN BASED
UPON THE LOW LEVEL DEPTH OF THE COLD ADVECTION AS PER NAM/GFS BUFR
SOUNDINGS. TIMING OF THE FREEZING RAIN ONSET WOULD BE FROM AROUND
08Z-09Z IN NORTHWEST ALABAMA...TO AROUND 10Z FROM CULLMAN COUNTY
EXTENDING NORTHEAST THROUGH MARSHALL TO JACKSON COUNTIES AND AROUND
11Z IN DEKALB COUNTY IN NORTHEAST ALABAMA.

FORECAST SOUNDINGS INDICATE THAT FREEZING RAIN SHOULD COMBINE WITH
AND CHANGE OVER TO ALL SLEET BY BETWEEN THE 14Z-16Z TIME FRAME IN
THE MORNING. BY THIS TIME PERIOD...THE LOWER LAYER AT OR BELOW 900
MILLIBARS COOLS BELOW FREEZING SUFFICIENTLY ENOUGH FOR CONDITIONS TO
BE MORE CONDUCIVE FOR SLEET ACROSS THE FORECAST AREA. SOME OF THE
AREA WILL SEE SLEET AMOUNTS UP TO A HALF OF AN INCH...WITH GENERALLY
LIGHT SNOW AMOUNTS EXPECTED BETWEEN LATE MORNING AND INTO THE
AFTERNOON HOURS. THE MODELS ARE AGAIN TODAY SLIGHTLY SLOWER INVOLVING
THE PRECIP EXITING THE REGION BY AFTERNOON. WILL KEEP TEMPS NEARLY
STEADY DURING THE DAY CLOSE TO MODEL GUIDANCE NUMBERS.

COLD HIGH PRESSURE WILL PROGRESSIVELY SHIFT SOUTHEAST ACROSS THE
REGION ON FRIDAY...WITH VERY COLD MORNING TEMPS AT AROUND 25 DEGREES
BELOW NORMAL EXPECTED. THE GFS AND ECMWF MODELS SHIFT THE HIGH
PRESSURE RIDGE AXIS SLIGHTLY EAST OF THE FORECAST AREA BY SATURDAY
AFTERNOON...WITH A LOW LEVEL SOUTHERLY FLOW EXPECTED.

TEMPS WILL FINALLY GET CLOSE TO NORMAL BY SUNDAY AND MONDAY...WITH A
MID TO UPPER LEVEL SOUTHWEST FLOW CONTINUING INTO THE EARLY PART OF
NEXT WEEK. THE GFS AND ECMWF MODELS DIFFER INVOLVING THE NORTHWARD
MOVEMENT OF LOW LEVEL MOISTURE OUT OF THE GULF OF MEXICO ALONG AND
AHEAD OF AN AREA OF LOW PRESSURE IN THE NORTHERN GULF OF MEXICO. THE
ECMWF MODEL KEEPS THE FORECAST AREA NORTH OF A WEAK AREA OF LOW
PRESSURE IN THE GULF OF MEXICO BETWEEN MONDAY THROUGH WEDNESDAY. THE
GFS MODEL INDICATES A MORE NORTHWARD MOVEMENT OF LOW LEVEL
MOISTURE/PRECIP INTO THE FORECAST AREA DURING THIS TIME FRAME. HAVE
GONE WITH A COMPROMISE BETWEEN THE MODELS AND HAVE KEPT IN LOW
CHANCES FOR THE FORECAST AREA THROUGH THE LATTER PART OF THE EXTENDED
FORECAST PERIODS. WILL STAY CLOSER TO THE ECMWF MODEL TEMP GUIDANCE
THROUGH THE EXTENDED FORECAST TIME FRAME.

TT

&&

.AVIATION...
FOR 00Z TAFS...
COLD FRONT HAS NOW MOVED THROUGH BOTH TERMINALS AS OF 23Z WITH WINDS
SHIFTING N/NW AND GUSTING 20-25KTS. LIGHT TO MODERATE RAIN SHOWERS
WILL CONTINUE THROUGH 09Z...THEN TRANSITION TO FREEZING RAIN BETWEEN
9-11Z. THE TIMING OF THIS TRANSITION MAY CHANGE..MAINLY DUE TO HOW
QUICKLY BELOW FREEZING AIR ARRIVES INTO THE AREA. THE TEMPERATURES
BECOME COLD ENOUGH BY MID MORNING THURSDAY FOR A CHANGE OVER TO
-IP/SN WITH A HALF AN INCH OF SLEET ACCUMULATION POSSIBLE. CIGS ARE
EXPECTED TO BE BETWEEN 1000-1500FT THROUGH THE PERIOD AND MAY DURING
THE HEAVIER PERIODS OF RAIN DROP DOWN TO 700FT WITH VISIBILITIES
DROPPING BELOW 2 MILES. NW WINDS REMAIN GUSTY BETWEEN 20-25KTS
THROUGH THE TAF PERIOD. DRIER AIR BEGINS TO PUSH INTO THE AREA
THURSDAY AFTERNOON WITH CIGS INCREASING TO BETWEEN 1500-2000FT...THEN
EVENTUALLY CLEARING OUT BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 042324
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
524 PM CST WED MAR 4 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 257 PM CST WED MAR 4 2015/
THE 21Z SURFACE ANALYSIS INDICATED THAT THE COLD FRONT WAS EXTENDING
NORTHEAST FROM NEAR CORINTH MISSISSIPPI AND BARELY INTO THE FORECAST
AREA IN NORTHWEST ALABAMA NEAR FLORENCE...TO NEAR FAYETTEVILLE
TENNESSEE. A LARGE AREA OF MAINLY LIGHT TO MODERATE RAIN WAS MAINLY
ALONG AND BEHIND THE COLD FRONT ACROSS MUCH OF NORTHERN MISSISSIPPI
AND THROUGHOUT WEST AND MIDDLE TENNESSEE.

EXPECT SHOWERS/EMBEDDED STORMS TO CONTINUE TO INCREASE IN COVERAGE
ACROSS THE FORECAST AREA INTO THE EARLY-MID EVENING AS THE COLD FRONT
MOVES THROUGH THE FORECAST AREA. THE SHORT TERM MODELS ARE FAIRLY
SIMILAR INVOLVING HAVING THE COLD FRONT MOVE THROUGH THE AREA BY
AROUND 03Z TONIGHT. A WINTER STORM WARNING REMAINS IN EFFECT FOR THE
FORECAST AREA FROM 09Z-21Z ON THURSDAY. STRONG COLD ADVECTION WILL
IMMEDIATELY FILTER SOUTHEAST INTO THE FORECAST AREA BEHIND THE COLD
FRONT THROUGH THE OVERNIGHT HOURS. HAVE SLIGHTLY ADJUSTED THE TIMING
FORWARD OF THE EXPECTED TRANSITION FROM RAIN TO FREEZING RAIN BASED
UPON THE LOW LEVEL DEPTH OF THE COLD ADVECTION AS PER NAM/GFS BUFR
SOUNDINGS. TIMING OF THE FREEZING RAIN ONSET WOULD BE FROM AROUND
08Z-09Z IN NORTHWEST ALABAMA...TO AROUND 10Z FROM CULLMAN COUNTY
EXTENDING NORTHEAST THROUGH MARSHALL TO JACKSON COUNTIES AND AROUND
11Z IN DEKALB COUNTY IN NORTHEAST ALABAMA.

FORECAST SOUNDINGS INDICATE THAT FREEZING RAIN SHOULD COMBINE WITH
AND CHANGE OVER TO ALL SLEET BY BETWEEN THE 14Z-16Z TIME FRAME IN
THE MORNING. BY THIS TIME PERIOD...THE LOWER LAYER AT OR BELOW 900
MILLIBARS COOLS BELOW FREEZING SUFFICIENTLY ENOUGH FOR CONDITIONS TO
BE MORE CONDUCIVE FOR SLEET ACROSS THE FORECAST AREA. SOME OF THE
AREA WILL SEE SLEET AMOUNTS UP TO A HALF OF AN INCH...WITH GENERALLY
LIGHT SNOW AMOUNTS EXPECTED BETWEEN LATE MORNING AND INTO THE
AFTERNOON HOURS. THE MODELS ARE AGAIN TODAY SLIGHTLY SLOWER INVOLVING
THE PRECIP EXITING THE REGION BY AFTERNOON. WILL KEEP TEMPS NEARLY
STEADY DURING THE DAY CLOSE TO MODEL GUIDANCE NUMBERS.

COLD HIGH PRESSURE WILL PROGRESSIVELY SHIFT SOUTHEAST ACROSS THE
REGION ON FRIDAY...WITH VERY COLD MORNING TEMPS AT AROUND 25 DEGREES
BELOW NORMAL EXPECTED. THE GFS AND ECMWF MODELS SHIFT THE HIGH
PRESSURE RIDGE AXIS SLIGHTLY EAST OF THE FORECAST AREA BY SATURDAY
AFTERNOON...WITH A LOW LEVEL SOUTHERLY FLOW EXPECTED.

TEMPS WILL FINALLY GET CLOSE TO NORMAL BY SUNDAY AND MONDAY...WITH A
MID TO UPPER LEVEL SOUTHWEST FLOW CONTINUING INTO THE EARLY PART OF
NEXT WEEK. THE GFS AND ECMWF MODELS DIFFER INVOLVING THE NORTHWARD
MOVEMENT OF LOW LEVEL MOISTURE OUT OF THE GULF OF MEXICO ALONG AND
AHEAD OF AN AREA OF LOW PRESSURE IN THE NORTHERN GULF OF MEXICO. THE
ECMWF MODEL KEEPS THE FORECAST AREA NORTH OF A WEAK AREA OF LOW
PRESSURE IN THE GULF OF MEXICO BETWEEN MONDAY THROUGH WEDNESDAY. THE
GFS MODEL INDICATES A MORE NORTHWARD MOVEMENT OF LOW LEVEL
MOISTURE/PRECIP INTO THE FORECAST AREA DURING THIS TIME FRAME. HAVE
GONE WITH A COMPROMISE BETWEEN THE MODELS AND HAVE KEPT IN LOW
CHANCES FOR THE FORECAST AREA THROUGH THE LATTER PART OF THE EXTENDED
FORECAST PERIODS. WILL STAY CLOSER TO THE ECMWF MODEL TEMP GUIDANCE
THROUGH THE EXTENDED FORECAST TIME FRAME.

TT

&&

.AVIATION...
FOR 00Z TAFS...
COLD FRONT HAS NOW MOVED THROUGH BOTH TERMINALS AS OF 23Z WITH WINDS
SHIFTING N/NW AND GUSTING 20-25KTS. LIGHT TO MODERATE RAIN SHOWERS
WILL CONTINUE THROUGH 09Z...THEN TRANSITION TO FREEZING RAIN BETWEEN
9-11Z. THE TIMING OF THIS TRANSITION MAY CHANGE..MAINLY DUE TO HOW
QUICKLY BELOW FREEZING AIR ARRIVES INTO THE AREA. THE TEMPERATURES
BECOME COLD ENOUGH BY MID MORNING THURSDAY FOR A CHANGE OVER TO
-IP/SN WITH A HALF AN INCH OF SLEET ACCUMULATION POSSIBLE. CIGS ARE
EXPECTED TO BE BETWEEN 1000-1500FT THROUGH THE PERIOD AND MAY DURING
THE HEAVIER PERIODS OF RAIN DROP DOWN TO 700FT WITH VISIBILITIES
DROPPING BELOW 2 MILES. NW WINDS REMAIN GUSTY BETWEEN 20-25KTS
THROUGH THE TAF PERIOD. DRIER AIR BEGINS TO PUSH INTO THE AREA
THURSDAY AFTERNOON WITH CIGS INCREASING TO BETWEEN 1500-2000FT...THEN
EVENTUALLY CLEARING OUT BY EARLY EVENING.

STUMPF

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 042057
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
257 PM CST WED MAR 4 2015

.DISCUSSION...
THE 21Z SURFACE ANALYSIS INDICATED THAT THE COLD FRONT WAS EXTENDING
NORTHEAST FROM NEAR CORINTH MISSISSIPPI AND BARELY INTO THE FORECAST
AREA IN NORTHWEST ALABAMA NEAR FLORENCE...TO NEAR FAYETTEVILLE
TENNESSEE. A LARGE AREA OF MAINLY LIGHT TO MODERATE RAIN WAS MAINLY
ALONG AND BEHIND THE COLD FRONT ACROSS MUCH OF NORTHERN MISSISSIPPI
AND THROUGHOUT WEST AND MIDDLE TENNESSEE.

EXPECT SHOWERS/EMBEDDED STORMS TO CONTINUE TO INCREASE IN COVERAGE
ACROSS THE FORECAST AREA INTO THE EARLY-MID EVENING AS THE COLD FRONT
MOVES THROUGH THE FORECAST AREA. THE SHORT TERM MODELS ARE FAIRLY
SIMILAR INVOLVING HAVING THE COLD FRONT MOVE THROUGH THE AREA BY
AROUND 03Z TONIGHT. A WINTER STORM WARNING REMAINS IN EFFECT FOR THE
FORECAST AREA FROM 09Z-21Z ON THURSDAY. STRONG COLD ADVECTION WILL
IMMEDIATELY FILTER SOUTHEAST INTO THE FORECAST AREA BEHIND THE COLD
FRONT THROUGH THE OVERNIGHT HOURS. HAVE SLIGHTLY ADJUSTED THE TIMING
FORWARD OF THE EXPECTED TRANSITION FROM RAIN TO FREEZING RAIN BASED
UPON THE LOW LEVEL DEPTH OF THE COLD ADVECTION AS PER NAM/GFS BUFR
SOUNDINGS. TIMING OF THE FREEZING RAIN ONSET WOULD BE FROM AROUND
08Z-09Z IN NORTHWEST ALABAMA...TO AROUND 10Z FROM CULLMAN COUNTY
EXTENDING NORTHEAST THROUGH MARSHALL TO JACKSON COUNTIES AND AROUND
11Z IN DEKALB COUNTY IN NORTHEAST ALABAMA.

FORECAST SOUNDINGS INDICATE THAT FREEZING RAIN SHOULD COMBINE WITH
AND CHANGE OVER TO ALL SLEET BY BETWEEN THE 14Z-16Z TIME FRAME IN
THE MORNING. BY THIS TIME PERIOD...THE LOWER LAYER AT OR BELOW 900
MILLIBARS COOLS BELOW FREEZING SUFFICIENTLY ENOUGH FOR CONDITIONS TO
BE MORE CONDUCIVE FOR SLEET ACROSS THE FORECAST AREA. SOME OF THE
AREA WILL SEE SLEET AMOUNTS UP TO A HALF OF AN INCH...WITH GENERALLY
LIGHT SNOW AMOUNTS EXPECTED BETWEEN LATE MORNING AND INTO THE
AFTERNOON HOURS. THE MODELS ARE AGAIN TODAY SLIGHTLY SLOWER INVOLVING
THE PRECIP EXITING THE REGION BY AFTERNOON. WILL KEEP TEMPS NEARLY
STEADY DURING THE DAY CLOSE TO MODEL GUIDANCE NUMBERS.

COLD HIGH PRESSURE WILL PROGRESSIVELY SHIFT SOUTHEAST ACROSS THE
REGION ON FRIDAY...WITH VERY COLD MORNING TEMPS AT AROUND 25 DEGREES
BELOW NORMAL EXPECTED. THE GFS AND ECMWF MODELS SHIFT THE HIGH
PRESSURE RIDGE AXIS SLIGHTLY EAST OF THE FORECAST AREA BY SATURDAY
AFTERNOON...WITH A LOW LEVEL SOUTHERLY FLOW EXPECTED.

TEMPS WILL FINALLY GET CLOSE TO NORMAL BY SUNDAY AND MONDAY...WITH A
MID TO UPPER LEVEL SOUTHWEST FLOW CONTINUING INTO THE EARLY PART OF
NEXT WEEK. THE GFS AND ECMWF MODELS DIFFER INVOLVING THE NORTHWARD
MOVEMENT OF LOW LEVEL MOISTURE OUT OF THE GULF OF MEXICO ALONG AND
AHEAD OF AN AREA OF LOW PRESSURE IN THE NORTHERN GULF OF MEXICO. THE
ECMWF MODEL KEEPS THE FORECAST AREA NORTH OF A WEAK AREA OF LOW
PRESSURE IN THE GULF OF MEXICO BETWEEN MONDAY THROUGH WEDNESDAY. THE
GFS MODEL INDICATES A MORE NORTHWARD MOVEMENT OF LOW LEVEL
MOISTURE/PRECIP INTO THE FORECAST AREA DURING THIS TIME FRAME. HAVE
GONE WITH A COMPROMISE BETWEEN THE MODELS AND HAVE KEPT IN LOW
CHANCES FOR THE FORECAST AREA THROUGH THE LATTER PART OF THE EXTENDED
FORECAST PERIODS. WILL STAY CLOSER TO THE ECMWF MODEL TEMP GUIDANCE
THROUGH THE EXTENDED FORECAST TIME FRAME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    27  30  21  40 / 100  80  10   0
SHOALS        25  29  18  39 / 100  70  10   0
VINEMONT      28  31  21  38 / 100  80  10   0
FAYETTEVILLE  25  28  17  37 / 100  70  10   0
ALBERTVILLE   32  33  22  42 / 100  80  10   0
FORT PAYNE    34  35  22  42 / 100  80  10   0

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 042057
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
257 PM CST WED MAR 4 2015

.DISCUSSION...
THE 21Z SURFACE ANALYSIS INDICATED THAT THE COLD FRONT WAS EXTENDING
NORTHEAST FROM NEAR CORINTH MISSISSIPPI AND BARELY INTO THE FORECAST
AREA IN NORTHWEST ALABAMA NEAR FLORENCE...TO NEAR FAYETTEVILLE
TENNESSEE. A LARGE AREA OF MAINLY LIGHT TO MODERATE RAIN WAS MAINLY
ALONG AND BEHIND THE COLD FRONT ACROSS MUCH OF NORTHERN MISSISSIPPI
AND THROUGHOUT WEST AND MIDDLE TENNESSEE.

EXPECT SHOWERS/EMBEDDED STORMS TO CONTINUE TO INCREASE IN COVERAGE
ACROSS THE FORECAST AREA INTO THE EARLY-MID EVENING AS THE COLD FRONT
MOVES THROUGH THE FORECAST AREA. THE SHORT TERM MODELS ARE FAIRLY
SIMILAR INVOLVING HAVING THE COLD FRONT MOVE THROUGH THE AREA BY
AROUND 03Z TONIGHT. A WINTER STORM WARNING REMAINS IN EFFECT FOR THE
FORECAST AREA FROM 09Z-21Z ON THURSDAY. STRONG COLD ADVECTION WILL
IMMEDIATELY FILTER SOUTHEAST INTO THE FORECAST AREA BEHIND THE COLD
FRONT THROUGH THE OVERNIGHT HOURS. HAVE SLIGHTLY ADJUSTED THE TIMING
FORWARD OF THE EXPECTED TRANSITION FROM RAIN TO FREEZING RAIN BASED
UPON THE LOW LEVEL DEPTH OF THE COLD ADVECTION AS PER NAM/GFS BUFR
SOUNDINGS. TIMING OF THE FREEZING RAIN ONSET WOULD BE FROM AROUND
08Z-09Z IN NORTHWEST ALABAMA...TO AROUND 10Z FROM CULLMAN COUNTY
EXTENDING NORTHEAST THROUGH MARSHALL TO JACKSON COUNTIES AND AROUND
11Z IN DEKALB COUNTY IN NORTHEAST ALABAMA.

FORECAST SOUNDINGS INDICATE THAT FREEZING RAIN SHOULD COMBINE WITH
AND CHANGE OVER TO ALL SLEET BY BETWEEN THE 14Z-16Z TIME FRAME IN
THE MORNING. BY THIS TIME PERIOD...THE LOWER LAYER AT OR BELOW 900
MILLIBARS COOLS BELOW FREEZING SUFFICIENTLY ENOUGH FOR CONDITIONS TO
BE MORE CONDUCIVE FOR SLEET ACROSS THE FORECAST AREA. SOME OF THE
AREA WILL SEE SLEET AMOUNTS UP TO A HALF OF AN INCH...WITH GENERALLY
LIGHT SNOW AMOUNTS EXPECTED BETWEEN LATE MORNING AND INTO THE
AFTERNOON HOURS. THE MODELS ARE AGAIN TODAY SLIGHTLY SLOWER INVOLVING
THE PRECIP EXITING THE REGION BY AFTERNOON. WILL KEEP TEMPS NEARLY
STEADY DURING THE DAY CLOSE TO MODEL GUIDANCE NUMBERS.

COLD HIGH PRESSURE WILL PROGRESSIVELY SHIFT SOUTHEAST ACROSS THE
REGION ON FRIDAY...WITH VERY COLD MORNING TEMPS AT AROUND 25 DEGREES
BELOW NORMAL EXPECTED. THE GFS AND ECMWF MODELS SHIFT THE HIGH
PRESSURE RIDGE AXIS SLIGHTLY EAST OF THE FORECAST AREA BY SATURDAY
AFTERNOON...WITH A LOW LEVEL SOUTHERLY FLOW EXPECTED.

TEMPS WILL FINALLY GET CLOSE TO NORMAL BY SUNDAY AND MONDAY...WITH A
MID TO UPPER LEVEL SOUTHWEST FLOW CONTINUING INTO THE EARLY PART OF
NEXT WEEK. THE GFS AND ECMWF MODELS DIFFER INVOLVING THE NORTHWARD
MOVEMENT OF LOW LEVEL MOISTURE OUT OF THE GULF OF MEXICO ALONG AND
AHEAD OF AN AREA OF LOW PRESSURE IN THE NORTHERN GULF OF MEXICO. THE
ECMWF MODEL KEEPS THE FORECAST AREA NORTH OF A WEAK AREA OF LOW
PRESSURE IN THE GULF OF MEXICO BETWEEN MONDAY THROUGH WEDNESDAY. THE
GFS MODEL INDICATES A MORE NORTHWARD MOVEMENT OF LOW LEVEL
MOISTURE/PRECIP INTO THE FORECAST AREA DURING THIS TIME FRAME. HAVE
GONE WITH A COMPROMISE BETWEEN THE MODELS AND HAVE KEPT IN LOW
CHANCES FOR THE FORECAST AREA THROUGH THE LATTER PART OF THE EXTENDED
FORECAST PERIODS. WILL STAY CLOSER TO THE ECMWF MODEL TEMP GUIDANCE
THROUGH THE EXTENDED FORECAST TIME FRAME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    27  30  21  40 / 100  80  10   0
SHOALS        25  29  18  39 / 100  70  10   0
VINEMONT      28  31  21  38 / 100  80  10   0
FAYETTEVILLE  25  28  17  37 / 100  70  10   0
ALBERTVILLE   32  33  22  42 / 100  80  10   0
FORT PAYNE    34  35  22  42 / 100  80  10   0

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041853 AAD
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1253 PM CST WED MAR 4 2015

.UPDATE...
FOR WINTER STORM WARNING FOR THURSDAY.

&&

.DISCUSSION...
HAVE AMENDED THE FORECAST DUE TO THE ISSUANCE OF THE WINTER STORM
WARNING FOR THE ENTIRE FORECAST AREA FROM 09Z-21Z ON THURSDAY. THE
COLD FRONT AT 19Z WAS LOCATED ALONG A LINE EXTENDING NORTHEAST FROM
NEAR SAVANNAH TENNESSEE...TO NEAR COLUMBIA TENNESSEE INTO SOUTHERN
MIDDLE TENNESSEE. THE CURRENT TIMING OF THE COLD FRONT MAKING IT INTO
THE FORECAST AREA BY LATER THIS AFTERNOON LOOKS TO BE IN GOOD SHAPE.
WILL NOT BE MAKING ANY OTHER CHANGES TO THE GOING FORECAST AT THIS
TIME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041853 AAD
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1253 PM CST WED MAR 4 2015

.UPDATE...
FOR WINTER STORM WARNING FOR THURSDAY.

&&

.DISCUSSION...
HAVE AMENDED THE FORECAST DUE TO THE ISSUANCE OF THE WINTER STORM
WARNING FOR THE ENTIRE FORECAST AREA FROM 09Z-21Z ON THURSDAY. THE
COLD FRONT AT 19Z WAS LOCATED ALONG A LINE EXTENDING NORTHEAST FROM
NEAR SAVANNAH TENNESSEE...TO NEAR COLUMBIA TENNESSEE INTO SOUTHERN
MIDDLE TENNESSEE. THE CURRENT TIMING OF THE COLD FRONT MAKING IT INTO
THE FORECAST AREA BY LATER THIS AFTERNOON LOOKS TO BE IN GOOD SHAPE.
WILL NOT BE MAKING ANY OTHER CHANGES TO THE GOING FORECAST AT THIS
TIME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041853 AAD
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1253 PM CST WED MAR 4 2015

.UPDATE...
FOR WINTER STORM WARNING FOR THURSDAY.

&&

.DISCUSSION...
HAVE AMENDED THE FORECAST DUE TO THE ISSUANCE OF THE WINTER STORM
WARNING FOR THE ENTIRE FORECAST AREA FROM 09Z-21Z ON THURSDAY. THE
COLD FRONT AT 19Z WAS LOCATED ALONG A LINE EXTENDING NORTHEAST FROM
NEAR SAVANNAH TENNESSEE...TO NEAR COLUMBIA TENNESSEE INTO SOUTHERN
MIDDLE TENNESSEE. THE CURRENT TIMING OF THE COLD FRONT MAKING IT INTO
THE FORECAST AREA BY LATER THIS AFTERNOON LOOKS TO BE IN GOOD SHAPE.
WILL NOT BE MAKING ANY OTHER CHANGES TO THE GOING FORECAST AT THIS
TIME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041853 AAD
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1253 PM CST WED MAR 4 2015

.UPDATE...
FOR WINTER STORM WARNING FOR THURSDAY.

&&

.DISCUSSION...
HAVE AMENDED THE FORECAST DUE TO THE ISSUANCE OF THE WINTER STORM
WARNING FOR THE ENTIRE FORECAST AREA FROM 09Z-21Z ON THURSDAY. THE
COLD FRONT AT 19Z WAS LOCATED ALONG A LINE EXTENDING NORTHEAST FROM
NEAR SAVANNAH TENNESSEE...TO NEAR COLUMBIA TENNESSEE INTO SOUTHERN
MIDDLE TENNESSEE. THE CURRENT TIMING OF THE COLD FRONT MAKING IT INTO
THE FORECAST AREA BY LATER THIS AFTERNOON LOOKS TO BE IN GOOD SHAPE.
WILL NOT BE MAKING ANY OTHER CHANGES TO THE GOING FORECAST AT THIS
TIME.

TT

&&

.AVIATION...
/ISSUED 1144 AM CST WED MAR 4 2015/
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.

LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR ALZ001>010-
     016.

TN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST THURSDAY FOR TNZ076-096-
     097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041744 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1144 AM CST WED MAR 4 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 956 AM CST WED MAR 4 2015/
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.


LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041744 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1144 AM CST WED MAR 4 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 956 AM CST WED MAR 4 2015/
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.


LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041744 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1144 AM CST WED MAR 4 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 956 AM CST WED MAR 4 2015/
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.


LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041744 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1144 AM CST WED MAR 4 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 956 AM CST WED MAR 4 2015/
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
FOR 18Z TAFS...STILL EXPECTING VCSH FOR THE NEXT FEW HOURS WITH -RA
MOVING INTO KMSL BY 19Z AND KHSV BY 22Z DUE TO A SLOW MOVING FRONT
THAT IS SINKING SOUTHEAST. AN ISOLATED THUNDERSTORM IS POSSIBLE BUT
CONFIDENCE IS TOO LOW ON LOCATION TO INCLUDE IN TAFS. RAIN COULD BE
MODERATE TO HEAVY AT TIMES AFTER 23/00Z AND WILL TRANSITION TO
FREEZING RAIN AROUND 9-11Z. AS WITH MOST WINTER EVENTS...THIS TIMING
COULD EASILY SHIFT IN EITHER DIRECTION BASED ON HOW THE TEMPERATURES
TREND. FZRA SHOULD THEN TRANSITION TO -IP/SN BY MORNING WITH POSSIBLY
A HALF AN INCH OF SLEET ACCUMULATION AFTER 14/16Z BEFORE IT ENDS.
WINDS WILL BE GUSTY THROUGH THE PERIOD WITH A FEW BRIEF LULLS
POSSIBLE.


LN

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041556 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
956 AM CST WED MAR 4 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
/ISSUED 545 AM CST WED MAR 4 2015/
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.PREV DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041556 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
956 AM CST WED MAR 4 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE WARM FRONT THAT MOVED THROUGH EARLY THIS MORNING HAS SUNK TO THE
SOUTH AND EVEN WASHED OUT A BIT. THE ONLY INDICATION OF A BOUNDARY IS
THAT WE ARE IN A MORE SOUTHWESTERLY FLOW VERSUS SOUTHERLY TO OUR
SOUTH. THE COLD FRONT AS OF 15Z IS THROUGH NASHVILLE AND STILL
SITTING NORTH OF OUR TN COUNTIES AND STRETCHING DOWN THROUGH WESTERN
MS AND IT IS NOT MOVING VERY FAST. TEMPERATURES BEHIND THE FRONT ARE
INTO THE MIDDLE 40S TO LOWER 50S IN NW TN. WITH THE SW FLOW...WE
PROBABLY WILL NOT WARM UP TOO MUCH MORE...MAYBE JUST A DEG OR
TWO...WITH 15Z TEMPS STILL IN THE LOWER TO UPPER 60S.

AS FOR THE UPDATE...DID NOT MAKE ANY CHANGES TO THE OVERNIGHT
FORECAST AS GUIDANCE SEEMS TO BE INITIALIZING WELL WITH THE CURRENT
TEMPS AND FRONT LOCATION. WE WILL NEED TO CONTINUE TO MONITOR THE
PROGRESSION/TIMING OF THE COLD AIR AS WELL AS WHEN THE PRECIP GETS
HERE. IN TERMS OF TODAY/THIS AFTERNOON...WENT WITH SCATTERED SHOWERS
THROUGH NOON AS THERE IS NOT MUCH OUT THERE RIGHT NOW. THERE ARE SOME
SHOWERS ALONG THE FRONT AND ARE JUST BARELY GETTING INTO FAR NW
LAUDERDALE COUNTY. WILL CONTINUE THE LIKELY POPS AFTER 18Z BUT WENT
WITH ISOLATED THUNDER WORDING INSTEAD OF SLIGHT CHANCE TO CONVEY HOW
ISOLATED IT WILL BE. KEPT THUNDER IN BECAUSE THERE IS SOME DECENT
INSTABILITY WITH THE FRONTAL PASSAGE ALONG WITH GOOD DEEP LAYER SHEAR
AND DEW POINTS IN THE LOWER 60S AHEAD OF IT. CANNOT RULE OUT A COUPLE
STORMS PRODUCING LOCALLY GUSTY WINDS AND BRIEF MODERATE TO HEAVY
RAINFALL WITH IT. AS WELL...IF THAT FRONT CONTINUES MOVING
SLOWLY...SOME OF THESE SHOWERS COULD TRAIN OVER THE SAME AREA WHICH
IS HAPPENING ALONG THE FRONT NOW. THIS COULD PRODUCE SOME PONDING OF
WATER IN LOW LYING AREAS.

LN

&&

.AVIATION...
/ISSUED 545 AM CST WED MAR 4 2015/
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.PREV DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041145 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
545 AM CST WED MAR 4 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041145 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
545 AM CST WED MAR 4 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041145 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
545 AM CST WED MAR 4 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041145 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
545 AM CST WED MAR 4 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 424 AM CST WED MAR 4 2015/

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
PERIODS OF SHOWERS ARE FORECAST TODAY. INCREASED INSTABILITY COULD
BRING AN ISOLATED T-STORM OR TWO...WITH THE PRIMARY THREAT FROM GUSTY
WINDS. MUCH COLDER TEMPS ARE EXPECTED THIS AFTERNOON AND EVENING...
AS AN ARCTIC COLD FRONT MOVES ACROSS THE REGION...AND TEMPS FALL
BELOW FREEZING AFTER MIDNIGHT WED NIGHT AND BEFORE DAYBREAK THU. THIS
WILL RESULT IN RAIN BECOMING A WINTRY MIX OF FREEZING RAIN AND SLEET.
SSW WINDS 10-20KT AT THE TAF START WILL BECOME WEST...THEN NNW AFTER
THE FRONT PASSES...WITH SOME GUSTS TO 25KT. LIGHTER WINDS AT THE
SURFACE THIS MORNING AND STRONGER WINDS ALOFT WILL BE CLOSE TO WIND
SHEAR CRITERIA.

RSB

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041024
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
424 AM CST WED MAR 4 2015

.DISCUSSION...

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
/ISSUED 1053 PM CST TUE MAR 3 2015/
FOR 06Z TAFS...ARCTIC CDFNT HAS PUSHED INTO EXTREME SERN MO. RA WAS
ALONG AND AHEAD OF THE CDFNT WITH A LITTLE POSSIBLE SLEET OVER
CENTRAL MO ATTM. AS THE CDFNT EDGES CLOSER TO THE CWA ON WEDNESDAY
THE CHC OF SHRA WILL CONTINUE OVER THE TAF SITES. THERE EVEN COULD BE
A FEW TSRA BY WEDNESDAY AFTN/EARLY EVENING. THE CDFNT WILL MOVE THRU
KMSL ARND 21Z AND KHSV BY 23Z.

WILL HOLD OFF ON ANY FREEZING/FROZEN PCPN IN TAFS FOR THIS TAF
ISSUANCE...SINCE MODEL SOUNDINGS SHOW THE BEST CHC FROZEN/FREEZING
PCPN WILL BE ARND 09Z OR LATER. OTHERWISE MVFR/IFR CONDITIONS ARE
EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    69  27  30  21 /  80 100  80  10
SHOALS        69  25  29  18 /  90 100  70  10
VINEMONT      68  28  31  21 /  70 100  80  10
FAYETTEVILLE  63  25  28  17 /  90 100  70  10
ALBERTVILLE   69  32  33  22 /  70 100  80  10
FORT PAYNE    68  34  35  22 /  70 100  80  10

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 041024
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
424 AM CST WED MAR 4 2015

.DISCUSSION...

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
/ISSUED 1053 PM CST TUE MAR 3 2015/
FOR 06Z TAFS...ARCTIC CDFNT HAS PUSHED INTO EXTREME SERN MO. RA WAS
ALONG AND AHEAD OF THE CDFNT WITH A LITTLE POSSIBLE SLEET OVER
CENTRAL MO ATTM. AS THE CDFNT EDGES CLOSER TO THE CWA ON WEDNESDAY
THE CHC OF SHRA WILL CONTINUE OVER THE TAF SITES. THERE EVEN COULD BE
A FEW TSRA BY WEDNESDAY AFTN/EARLY EVENING. THE CDFNT WILL MOVE THRU
KMSL ARND 21Z AND KHSV BY 23Z.

WILL HOLD OFF ON ANY FREEZING/FROZEN PCPN IN TAFS FOR THIS TAF
ISSUANCE...SINCE MODEL SOUNDINGS SHOW THE BEST CHC FROZEN/FREEZING
PCPN WILL BE ARND 09Z OR LATER. OTHERWISE MVFR/IFR CONDITIONS ARE
EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    69  27  30  21 /  80 100  80  10
SHOALS        69  25  29  18 /  90 100  70  10
VINEMONT      68  28  31  21 /  70 100  80  10
FAYETTEVILLE  63  25  28  17 /  90 100  70  10
ALBERTVILLE   69  32  33  22 /  70 100  80  10
FORT PAYNE    68  34  35  22 /  70 100  80  10

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 041024
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
424 AM CST WED MAR 4 2015

.DISCUSSION...

THE PREVIOUSLY ADVERTISED WARM FRONT HAS NOW MOVED NORTH OF THE
FORECAST AREA...WITH MANY LOCATIONS IN THE MID TO UPPER 60S.
MEANWHILE...A COLD FRONT EXTENDS FROM UPSTATE NEW
YORK...SOUTHWESTWARD INTO EASTERN OKLAHOMA. SHOWERS...AND A FEW
THUNDERSTORMS...WERE OBSERVED JUST ALONG THIS FRONT...MOVING TO THE
NORTHWEST ACROSS WESTERN TENNESSEE. THIS FRONT WILL MAKE ITS SLOW
PROGRESSION SOUTHEAST TODAY...WITH MODEL CONSENSUS MOVING THE FRONT
INTO THE NORTHWESTERN PORTION OF ALABAMA BY 18Z...AND THEN SLOWLY
MOVING EAST OF THE AREA BETWEEN 00Z AND 03Z. PRIOR TO THE FRONT
REACHING THE FORECAST AREA...FORECAST HIGHS INTO THE UPPER 60S...AND
POSSIBLE LOWER 70S ARE EXPECTED. SHOWERS AND ISOLATED THUNDERSTORMS
WILL ALSO BE POSSIBLE ALONG THE FRONT.

AS THE FRONT MOVES EAST OVER THE NEXT 12 TO 18 HOURS...A SOUTHERN
STREAM CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL PHASE
WITH A NORTHERN STREAM TROUGH. THE RESULTING LONGWAVE TROUGH WILL
SLOWLY PROGRESS EASTWARD...AS THE UPPER LEVEL JET STREAM
INTENSIFIES. THIS WILL PROVIDE AN ABUNDANCE OF LIFT BEHIND THE
FRONT...WITH WIDESPREAD SHOWERS EXPECTED TO DEVELOP BY THE EVENING.
MEANWHILE...THE SHALLOW COLD AIR BEHIND THE FRONT WILL MOVE IN FAIRLY
QUICKLY ACROSS THE FORECAST AREA...HOWEVER WITH TEMPERATURES RISING
TO NEAR 70 DEGREES PRIOR TO FRONTAL PASSAGE...IT WILL STILL BE AFTER
MIDNIGHT BEFORE TEMPERATURES FALL BELOW FREEZING. AS TEMPERATURES
FALL...RAIN WILL TRANSITION TO FREEZING RAIN FROM WEST TO EAST
THROUGH 12Z. MANY LOCATIONS ACROSS THE EAST MAY NOT SEE FROZEN PRECIP
UNTIL AFTER 12Z...HOWEVER HAVE KEPT A CHANCE FOR FREEZING RAIN MIXING
IN WITH RAIN...TO ACCOUNT FOR THE COLDER AIR POSSIBLY REACHING THESE
LOCATIONS SOONER THAN FORECAST. MODELS ARE COMING IN WITH BETTER
AGREEMENT THAT THE POST FRONTAL PRECIP WILL CONTINUE THROUGH AT LEAST
18Z...WITH MORE QPF THEN PREVIOUS RUNS. THEREFORE...INCREASED POPS
DURING THE 12Z TO 18Z TIME FRAME...WHICH PUTS THE EASTERN HALF OF THE
CWA IN FROZEN PRECIP LONGER. THEREFORE...ALSO MADE AN ADJUSTMENT TO
THE ICE ACCUMULATION GRIDS. CONFIDENCE IS A LITTLE ON THE LOW SIDE
CONCERNING THE SLEET AND SNOW MIXING IN WITH FREEZING RAIN. FORECAST
SOUNDINGS ACROSS THE BOARD SHOW THE WARM NOSE REMAINING IN PLACE
DURING THE HEAVIEST PRECIP...WITH THE TEMP PROFILE GOING BELOW
FREEZING JUST AS THE DRIER AIR FILTERS IN. HOWEVER KEPT THE CHANCE
FOR MODERATE SLEET ACROSS THE NORTHWESTERN PORTION OF THE AREA AND
LEFT THE SLEET/SNOW AMOUNTS UNCHANGED.

SLEET/SNOW ACCUMULATIONS OF UP TO AN INCH ARE POSSIBLE...MAINLY
ACROSS THE NORTHWESTERN 3 COUNTIES IN ALABAMA AND ALL OF SOUTHERN
MIDDLE TENNESSEE. ICE ACCUMULATIONS OF ONE TO THREE TENTHS OF AN
INCH WILL ALSO BE POSSIBLE. GIVEN THAT WE WILL BE FAIRLY WARM PRIOR
TO THE ONSET OF FROZEN PRECIP...MOST OF THE ACCUMULATIONS WILL BE ON
ELEVATED SURFACES. HOWEVER...THE MAJORITY OF THE FROZEN PRECIP IS
EXPECTED TO OCCUR JUST BEFORE...AND DURING...MORNING COMMUTE
TOMORROW...WHICH MAY CREATE HAZARDOUS TRAVEL CONDITIONS.
ADDITIONALLY...WINDS WILL BE IN THE 15 TO 20 KT RANGE WHILE PRECIP
IS FALLING...WHICH MAY LEAD TO GREATER ICE ACCUMULATIONS THAN
FORECAST. GIVEN THIS UNCERTAINTY...HAVE DECIDED TO INCLUDE
MADISON...MORGAN...AND CULLMAN COUNTIES TO THE WATCH...GIVEN THAT
QPF AMOUNTS MAY BE HIGHER THAN FORECAST IN THESE LOCATIONS AFTER
12Z.

PRECIP WILL TAPER OFF BY 18Z...WITH LINGERING LIGHT SNOW FLURRIES
POSSIBLE DURING THE AFTERNOON. TEMPERATURES WILL NOT WARM VERY MUCH
DURING THE DAY...AND MOST LOCATIONS WILL LIKELY STAY BELOW FREEZING.
TEMPS WILL BOTTOM OUT EARLY FRIDAY MORNING...WITH LOWS DROPPING INTO
THE TEENS. THIS...COMBINED WITH WINDS STAYING NEAR 10 KTS...WILL
CREATE FRIGID CONDITIONS ACROSS THE FORECAST AREA. THE GOOD NEWS IS
THAT THE FORECAST AREA WILL THEN EXPERIENCE A WARMING TREND DURING
THE EXTENDED PORTION OF THE FORECAST PERIOD. MODEL GUIDANCE BEYOND
FRIDAY IS INCONSISTENT...SO KEPT A BLEND OF THE GUIDANCE...WITH THE
CHANCE FOR LIGHT PRECIP RETURNING TO THE AREA ON MONDAY. TEMPS WILL
MODERATE TO NEAR NORMAL FOR THIS TIME OF YEAR.

73

&&

.AVIATION...
/ISSUED 1053 PM CST TUE MAR 3 2015/
FOR 06Z TAFS...ARCTIC CDFNT HAS PUSHED INTO EXTREME SERN MO. RA WAS
ALONG AND AHEAD OF THE CDFNT WITH A LITTLE POSSIBLE SLEET OVER
CENTRAL MO ATTM. AS THE CDFNT EDGES CLOSER TO THE CWA ON WEDNESDAY
THE CHC OF SHRA WILL CONTINUE OVER THE TAF SITES. THERE EVEN COULD BE
A FEW TSRA BY WEDNESDAY AFTN/EARLY EVENING. THE CDFNT WILL MOVE THRU
KMSL ARND 21Z AND KHSV BY 23Z.

WILL HOLD OFF ON ANY FREEZING/FROZEN PCPN IN TAFS FOR THIS TAF
ISSUANCE...SINCE MODEL SOUNDINGS SHOW THE BEST CHC FROZEN/FREEZING
PCPN WILL BE ARND 09Z OR LATER. OTHERWISE MVFR/IFR CONDITIONS ARE
EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    69  27  30  21 /  80 100  80  10
SHOALS        69  25  29  18 /  90 100  70  10
VINEMONT      68  28  31  21 /  70 100  80  10
FAYETTEVILLE  63  25  28  17 /  90 100  70  10
ALBERTVILLE   69  32  33  22 /  70 100  80  10
FORT PAYNE    68  34  35  22 /  70 100  80  10

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     ALZ001>007-016.

TN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
     TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 040453
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1053 PM CST TUE MAR 3 2015

.UPDATE...
FOR 06Z TAFS

&&

.DISCUSSION...
/ISSUED 808 PM CST TUE MAR 3 2015/
SFC OBS SHOW THAT THE WARM FRONT HAS MADE IT TO THE SRN OHIO VALLEY
WHILE THE ARCTIC FRONT WAS EXTENDING ACROSS SERN MO. LOW CLOUDS AND
FOG WILL CONTINUE OVER MOST OF THE CWA OVERNIGHT. THUS WILL KEEP
AREAS OF FOG WORDING IN THE FCST AND WILL MENTION IN THE HWO. VSBYS
MAY DROP TO BELOW 1 MILE OR LOWER IN SOME LOCATIONS TONIGHT...BUT
DONT THINK COVERAGE IS WIDESPREAD ENOUGH FOR AN ADVISORY ATTM. WILL
MONITOR. ALSO HAVE NOT SEEN ANY LIGHTNING STRIKES ACROSS THE ENTIRE
REGION SO FAR. THE BEST CHC OF THUNDER LOOKS TO BE WEST OF THE TN
VALLEY...FOR LOCATIONS CLOSER TO THE CDFNT (WRN KY/TN). WILL REMOVE
THUNDER IN THE FCST/GRIDS.

OTHERWISE TEMPS WILL NOT DROP MUCH OVERNIGHT IF AT ALL...AND MANY
LOCATIONS WILL SEE TEMPS RISE A FEW DEGREES THANKS TO SOUTH WINDS/LOW
CLOUDS. REST OF THE FCST PARAMETERS LOOK GOOD ATTM.

07


.PREV DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 06Z TAFS...ARCTIC CDFNT HAS PUSHED INTO EXTREME SERN MO. RA WAS
ALONG AND AHEAD OF THE CDFNT WITH A LITTLE POSSIBLE SLEET OVER
CENTRAL MO ATTM. AS THE CDFNT EDGES CLOSER TO THE CWA ON WEDNESDAY
THE CHC OF SHRA WILL CONTINUE OVER THE TAF SITES. THERE EVEN COULD BE
A FEW TSRA BY WEDNESDAY AFTN/EARLY EVENING. THE CDFNT WILL MOVE THRU
KMSL ARND 21Z AND KHSV BY 23Z.

WILL HOLD OFF ON ANY FREEZING/FROZEN PCPN IN TAFS FOR THIS TAF
ISSUANCE...SINCE MODEL SOUNDINGS SHOW THE BEST CHC FROZEN/FREEZING
PCPN WILL BE ARND 09Z OR LATER. OTHERWISE MVFR/IFR CONDITIONS ARE
EXPECTED THRU THE FCST PERIOD.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 040453
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1053 PM CST TUE MAR 3 2015

.UPDATE...
FOR 06Z TAFS

&&

.DISCUSSION...
/ISSUED 808 PM CST TUE MAR 3 2015/
SFC OBS SHOW THAT THE WARM FRONT HAS MADE IT TO THE SRN OHIO VALLEY
WHILE THE ARCTIC FRONT WAS EXTENDING ACROSS SERN MO. LOW CLOUDS AND
FOG WILL CONTINUE OVER MOST OF THE CWA OVERNIGHT. THUS WILL KEEP
AREAS OF FOG WORDING IN THE FCST AND WILL MENTION IN THE HWO. VSBYS
MAY DROP TO BELOW 1 MILE OR LOWER IN SOME LOCATIONS TONIGHT...BUT
DONT THINK COVERAGE IS WIDESPREAD ENOUGH FOR AN ADVISORY ATTM. WILL
MONITOR. ALSO HAVE NOT SEEN ANY LIGHTNING STRIKES ACROSS THE ENTIRE
REGION SO FAR. THE BEST CHC OF THUNDER LOOKS TO BE WEST OF THE TN
VALLEY...FOR LOCATIONS CLOSER TO THE CDFNT (WRN KY/TN). WILL REMOVE
THUNDER IN THE FCST/GRIDS.

OTHERWISE TEMPS WILL NOT DROP MUCH OVERNIGHT IF AT ALL...AND MANY
LOCATIONS WILL SEE TEMPS RISE A FEW DEGREES THANKS TO SOUTH WINDS/LOW
CLOUDS. REST OF THE FCST PARAMETERS LOOK GOOD ATTM.

07


.PREV DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 06Z TAFS...ARCTIC CDFNT HAS PUSHED INTO EXTREME SERN MO. RA WAS
ALONG AND AHEAD OF THE CDFNT WITH A LITTLE POSSIBLE SLEET OVER
CENTRAL MO ATTM. AS THE CDFNT EDGES CLOSER TO THE CWA ON WEDNESDAY
THE CHC OF SHRA WILL CONTINUE OVER THE TAF SITES. THERE EVEN COULD BE
A FEW TSRA BY WEDNESDAY AFTN/EARLY EVENING. THE CDFNT WILL MOVE THRU
KMSL ARND 21Z AND KHSV BY 23Z.

WILL HOLD OFF ON ANY FREEZING/FROZEN PCPN IN TAFS FOR THIS TAF
ISSUANCE...SINCE MODEL SOUNDINGS SHOW THE BEST CHC FROZEN/FREEZING
PCPN WILL BE ARND 09Z OR LATER. OTHERWISE MVFR/IFR CONDITIONS ARE
EXPECTED THRU THE FCST PERIOD.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 040208
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
808 PM CST TUE MAR 3 2015

.UPDATE...
REMOVED THUNDER AND KEPT AREAS OF FOG WORDING.

&&

.DISCUSSION...
SFC OBS SHOW THAT THE WARM FRONT HAS MADE IT TO THE SRN OHIO VALLEY
WHILE THE ARCTIC FRONT WAS EXTENDING ACROSS SERN MO. LOW CLOUDS AND
FOG WILL CONTINUE OVER MOST OF THE CWA OVERNIGHT. THUS WILL KEEP
AREAS OF FOG WORDING IN THE FCST AND WILL MENTION IN THE HWO. VSBYS
MAY DROP TO BELOW 1 MILE OR LOWER IN SOME LOCATIONS TONIGHT...BUT
DONT THINK COVERAGE IS WIDESPREAD ENOUGH FOR AN ADVISORY ATTM. WILL
MONITOR. ALSO HAVE NOT SEEN ANY LIGHTNING STRIKES ACROSS THE ENTIRE
REGION SO FAR. THE BEST CHC OF THUNDER LOOKS TO BE WEST OF THE TN
VALLEY...FOR LOCATIONS CLOSER TO THE CDFNT (WRN KY/TN). WILL REMOVE
THUNDER IN THE FCST/GRIDS.

OTHERWISE TEMPS WILL NOT DROP MUCH OVERNIGHT IF AT ALL...AND MANY
LOCATIONS WILL SEE TEMPS RISE A FEW DEGREES THANKS TO SOUTH WINDS/LOW
CLOUDS. REST OF THE FCST PARAMETERS LOOK GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 554 PM CST TUE MAR 3 2015/
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.PREV DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 040208
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
808 PM CST TUE MAR 3 2015

.UPDATE...
REMOVED THUNDER AND KEPT AREAS OF FOG WORDING.

&&

.DISCUSSION...
SFC OBS SHOW THAT THE WARM FRONT HAS MADE IT TO THE SRN OHIO VALLEY
WHILE THE ARCTIC FRONT WAS EXTENDING ACROSS SERN MO. LOW CLOUDS AND
FOG WILL CONTINUE OVER MOST OF THE CWA OVERNIGHT. THUS WILL KEEP
AREAS OF FOG WORDING IN THE FCST AND WILL MENTION IN THE HWO. VSBYS
MAY DROP TO BELOW 1 MILE OR LOWER IN SOME LOCATIONS TONIGHT...BUT
DONT THINK COVERAGE IS WIDESPREAD ENOUGH FOR AN ADVISORY ATTM. WILL
MONITOR. ALSO HAVE NOT SEEN ANY LIGHTNING STRIKES ACROSS THE ENTIRE
REGION SO FAR. THE BEST CHC OF THUNDER LOOKS TO BE WEST OF THE TN
VALLEY...FOR LOCATIONS CLOSER TO THE CDFNT (WRN KY/TN). WILL REMOVE
THUNDER IN THE FCST/GRIDS.

OTHERWISE TEMPS WILL NOT DROP MUCH OVERNIGHT IF AT ALL...AND MANY
LOCATIONS WILL SEE TEMPS RISE A FEW DEGREES THANKS TO SOUTH WINDS/LOW
CLOUDS. REST OF THE FCST PARAMETERS LOOK GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 554 PM CST TUE MAR 3 2015/
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.PREV DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 032354
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
554 PM CST TUE MAR 3 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 032354
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
554 PM CST TUE MAR 3 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 032354
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
554 PM CST TUE MAR 3 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 032354
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
554 PM CST TUE MAR 3 2015

.UPDATE...
FOR 00Z TAFS

&&

.DISCUSSION...
/ISSUED 521 PM CST TUE MAR 3 2015/
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

&&

.AVIATION...
FOR 00Z TAFS...ARCTIC CDFNT ACROSS CENTRAL MO WHILE A WARM FRONT
EXTENDED ACROSS CENTRAL AL. THIS COMBINATION OF FRONTS WILL CONTINUE
THE CHC OF RAIN ACROSS THE TAF SITES THRU MUCH OF THE FCST PERIOD.
THERE COULD ALSO BE AN ISOLATED TSRA ACROSS THE TN VALLEY MAINLY
THIS EVENING. THE CDFNT WILL BEGIN TO PASS OVER KMSL ARND 20Z AND
KHSV BY 21Z WEDNESDAY. OTHERWISE EXPECT IFR CONDITIONS FOR THE NEXT
24 HOURS AT BOTH TAF SITES.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 032321
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
521 PM CST TUE MAR 3 2015

.UPDATE...
DID A QUICK UPDATE TO ADD AREAS OF FOG.

&&

.DISCUSSION...
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

&&

.AVIATION...
/ISSUED 1117 AM CST TUE MAR 3 2015/
FOR 18Z TAFS...WILL CONTINUE WITH IFR/LIFR CONDITIONS DUE TO LOW
CEILINGS THROUGH THE FORECAST PERIODS FOR HSV AND MSL. FOG WILL ALSO
INCREASE WITH TIME OVERNIGHT AT BOTH TERMINALS. HAVE SHIFTED WINDS
AROUND TO THE NORTHWEST AT MSL BY THE END OF THE FORECAST PERIOD DUE
TO A COLD FRONTAL PASSAGE AND MADE PRECIP PREDOMINANT.

TT

&&

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

KULA

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 032321
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
521 PM CST TUE MAR 3 2015

.UPDATE...
DID A QUICK UPDATE TO ADD AREAS OF FOG.

&&

.DISCUSSION...
HAD A REPORT OF SOME LOCALIZED DENSE FOG OVER CULLMAN COUNTY...SO
WENT AHEAD AND ADDED AREAS OF FOG IN THE ZONES/FCST. ALSO WILL GO
WITH ISOLATED THUNDER WORDING...DUE TO FAIRLY STABLE CONDITIONS
ACROSS THE CWA TONIGHT.

07

&&

.AVIATION...
/ISSUED 1117 AM CST TUE MAR 3 2015/
FOR 18Z TAFS...WILL CONTINUE WITH IFR/LIFR CONDITIONS DUE TO LOW
CEILINGS THROUGH THE FORECAST PERIODS FOR HSV AND MSL. FOG WILL ALSO
INCREASE WITH TIME OVERNIGHT AT BOTH TERMINALS. HAVE SHIFTED WINDS
AROUND TO THE NORTHWEST AT MSL BY THE END OF THE FORECAST PERIOD DUE
TO A COLD FRONTAL PASSAGE AND MADE PRECIP PREDOMINANT.

TT

&&

.PREV DISCUSSION...
/ISSUED 350 PM CST TUE MAR 3 2015/

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

KULA

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 032150
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
350 PM CST TUE MAR 3 2015

...SIGNIFICANT WINTER STORM LIKELY ON THURSDAY ACROSS NORTHWEST
ALABAMA AND SOUTHERN MIDDLE TENNESSEE...

.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

.LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

KULA

&&

.AVIATION...
/ISSUED 1117 AM CST TUE MAR 3 2015/
FOR 18Z TAFS...WILL CONTINUE WITH IFR/LIFR CONDITIONS DUE TO LOW
CEILINGS THROUGH THE FORECAST PERIODS FOR HSV AND MSL. FOG WILL ALSO
INCREASE WITH TIME OVERNIGHT AT BOTH TERMINALS. HAVE SHIFTED WINDS
AROUND TO THE NORTHWEST AT MSL BY THE END OF THE FORECAST PERIOD DUE
TO A COLD FRONTAL PASSAGE AND MADE PRECIP PREDOMINANT.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    60  70  29  31 /  60  80 100  50
SHOALS        60  65  27  30 /  80  80 100  50
VINEMONT      59  68  31  31 /  60  70 100  60
FAYETTEVILLE  59  63  25  28 /  70  80 100  50
ALBERTVILLE   57  69  34  33 /  60  70 100  60
FORT PAYNE    57  68  35  34 /  60  70 100  60

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 032150
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
350 PM CST TUE MAR 3 2015

...SIGNIFICANT WINTER STORM LIKELY ON THURSDAY ACROSS NORTHWEST
ALABAMA AND SOUTHERN MIDDLE TENNESSEE...

.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...

A VERY WARM AND HUMID AIRMASS IS IN PLACE ACROSS THE TN VALLEY AS A
WARM FRONT MOVES NORTH/NE FROM CENTRAL AL/GA. WIDESPREAD SHOWERS AND
POSSIBLY THUNDERSTORMS ARE EXPECTED TONIGHT AS ELEVATED INSTABILITY
AND WIND SHEAR INCREASES. THIS WILL OCCUR AHEAD OF THE WIDELY
ANTICIPATED MERGING OF THE SUBTROPICAL AND POLAR JETS TAKING PLACE
AS TWO MID-LEVEL SHORTWAVE TROUGHS (ONE IN SUBTROPICAL JET AND ONE IN
POLAR JET) ACROSS THE PLAINS AND UPPER MIDWEST TONIGHT INTO TOMORROW.
AS THIS TRANSITION OCCURS, A HIGH SPEED UPPER JET STREAK IS FORECAST
TO MOVE JUST TO THE NORTH OF THE TN VALLEY INDUCING A STRONG LLJ
TONIGHT. THIS WILL ACT TO STEEPEN LOW-LEVEL LAPSE RATES LIKELY JUST
ENOUGH TO CAUSE SOME STRONGER UPDRAFTS WITHIN ISOLATED TO SCATTERED
THUNDERSTORMS FROM SOUTH TO NORTH ALONG THE WARM FRONT. A LOOK AT
INSTABILITY PARAMETERS INDICATES 0-3 KM MUCAPES BTWN 300-500 J/KG AS
THE WARM FRONT PASSES. MEANWHILE, WIND SHEAR PARAMETERS SHOW MODERATE
TO HIGH WIND SHEAR AT 0-3 KM 100-300 M2/S2, AND A 40-50 KTS LLJ. ALL
OF THIS MEANS THAT WE COULD HAVE SOME ROTATING UPDRAFTS AND POSSIBLE
SUDDEN GUSTS OF WIND UP TO 50 MPH WITH THE STRONGEST STORMS WITHIN
THE DOWNDRAFT OF THESE STORMS. THOUGH ROTATING UPDRAFTS ARE POSSIBLE,
THE THREAT FOR TORNADOES WILL LIKELY BE RATHER LOW AND SHORT-LIVED.
THE PRIMARY TIME PERIOD FOR THIS CONVECTIVE ACTIVITY WILL BE 6 PM
THROUGH AROUND 3 AM WEDNESDAY MORNING.

THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN LATE ON
WEDNESDAY MORNING. HOWEVER, A WARMING OF THE LAPSE RATES ALOFT LOOKS
TO OCCUR--POSSIBLY LIMITING THUNDERSTORM ACTIVITY INITIALLY BEFORE
THE ARCTIC COLD FRONT APPROACHES. HOWEVER, GIVEN THE COMPLEX TIMING
OF THE ARCTIC FRONT AS THE POSITIVELY TILTED TROUGH APPROACHES, HAVE
LEFT THUNDERSTORMS IN THE MORNING FOR NOW. MED RANGE GUIDANCE
CONTINUES TO SLOW THE PROGRESSION OF THE COLD FRONT AND THAT HAS
AFFECTED THE ONSET OF FROZEN PRECIPITATION ACROSS THE TN VALLEY AND
SUBSEQUENT ACCUMULATIONS. SO BASED ON ANALYSIS OF CURRENT MODEL
TRENDS, EXPECT THE FRONT TO PASS OVER NW AL/S MIDDLE TN REGION ON
WEDNESDAY AFTERNOON AROUND 18Z AND GRADUALLY PASS OVER THE REST OF
THE TN VALLEY BY 00Z. KEEP IN MIND THOUGH THAT DAYTIME TEMPERATURES
AHEAD OF THIS FRONT ON WEDNESDAY COULD BE AS HIGH AS 70 DEGREES!

GIVEN ALL OF THAT, AS THE FRONT PASSES, TEMPERATURES WILL RAPIDLY
FALL AFTER 18Z THROUGH EARLY THURSDAY MORNING. HOWEVER, TEMPERATURES
SHOULD NOT FALL TO FREEZING UNTIL CLOSE TO MIDNIGHT ACROSS NW AL AND
S MIDDLE TN WHICH SHOULD TRANSLATE TO A PRECIP TYPE CHANGE TO
FREEZING RAIN AND SLEET. THIS FREEZING RAIN/SLEET AND LIKELY A MIX
WITH RAIN (OVER SE PORTIONS OF AREA) AS WELL SHOULD CONTINUE TO MOVE
ACROSS THE REST OF THE AREA. AS TEMPERATURES BEGIN TO FALL ACROSS THE
REST OF THE AREA, THE FREEZING RAIN AND SLEET MIX WILL GRADUALLY
SHIFT TO THE SOUTHEAST WITH FREEZING RAIN LIKELY EXTENDING THROUGH
THURSDAY MORNING AT LEAST OVER OUR SOUTHEAST COUNTIES. A CHANGEOVER
TO ALL SNOW SHOULD THEN OCCUR LATE ON THURSDAY MORNING INTO THE
AFTERNOON. WITH THE HIGHEST QPF AMOUNTS EXPECTED TO BE ACROSS NW AL/S
MIDDLE TN, ICE ACCUMULATIONS OF 0.2-0.3 INCHES LOOK PROBABLE AND HAVE
ISSUED A WINTER STORM WATCH FOR THOSE AREAS. THERE DOES APPEAR TO BE
THE POSSIBILITY OF SNOW ACCUMULATIONS AS WELL MAINLY OVER THE AREAS
THAT HAVE BEEN BELOW FREEZING LONGER. HOWEVER, THE QPF IS LOWER
AFTER SUNRISE AND HAVE ONLY INCLUDED UP TO ONE INCH (HIGHEST AMOUNTS
OVER SOUTHERN MIDDLE TN) OF SNOW ACCUMULATION.

TEMPERATURES ARE NOT EXPECTED TO RISE ABOVE FREEZING ON THURSDAY
WHICH WILL MEAN THAT WHATEVER RAIN/ICE/SNOW ACCUMULATIONS OCCUR WILL
LIKELY NOT EVAPORATE MUCH. ONE GOOD NEWS/BAD NEWS ITEM IS THAT STRONG
CAA ON THE BACK SIDE OF THE FRONT WILL TRANSLATE TO 10-15 MPH
NORTHERLY WINDS WITH HIGHER GUSTS. THIS COULD HELP EVAPORATION SOME
BUT COULD ALSO CAUSE ICED TREES TO FALL. THE OTHER POSSIBLE
MITIGATING FACTOR IS THAT GROUND AND ROAD SURFACES WILL BE QUITE WARM
PRIOR TO COLD FRONT PASSAGE. LASTLY, THERE COULD BE SOME CLOUD BREAKS
LATE ON THURSDAY AFTERNOON BUT NOT SURE IT WILL BE ENOUGH TO MELT OR
EVAPORATE MOISTURE BEFORE TEMPERATURES NOSEDIVE RAPIDLY AFTER SUNSET
INTO THE TEENS BY EARLY FRIDAY MORNING.

SL.77

.LONG TERM (FRIDAY THROUGH TUESDAY)...

A PERIOD OF QUIETER WEATHER IS FORESEEN FOR MOST OF THE EXTENDED
PERIOD AS A MID-UPPER CONFLUENT PATTERN DEVELOPS ACROSS THE MID
SOUTH AND TN VALLEY OVER THE WEEKEND.  FAST MOVING SHORTWAVES IN THE
NORTHERN STREAM WILL RAPIDLY SKIRT BY TO OUR NORTH ON SATURDAY INTO
SUNDAY.  THE SWRN U.S. LOW EVOLUTION IS STILL UP FOR DEBATE, BUT
SOME OF THIS ENERGY MAY STREAK ACROSS THE GULF SOUTH AS WELL DURING
THIS PERIOD, BUT NEITHER BRINGING PRECIP OR A FRONTAL SYSTEM INTO
OUR REGION.

A SURFACE RIDGE WILL BROADEN ITSELF W-E ACROSS THE OZARKS TO THE MID
ATLANTIC STATES BY EARLY NEXT WEEK.  TEMPS WILL MODERATE RAPIDLY,
BUT NOT DUE TO WARM ADVECTION, BUT MORE TO COLUMN WARMING FROM
SUBSIDENCE AND INCREASING SOLAR HEATING EACH DAY.  THE SWRN U.S.
UPPER LOW IS PROGGED TO EVENTUALLY DISLODGE ITSELF BY EARLY TO MIDDLE
OF NEXT WEEK INTO TX OR PERHAPS INTO THE LWR MS VALLEY. TOO EARLY TO
INTRODUCE HIGH POPS, BUT WILL GO WITH SCHC POPS DAYS 6-7 AND VERY
NEAR SUGGESTED MODEL BLENDS GIVEN THE TIMING AND LOCATION DISPARITY
BETWEEN THE GFS AND ECWMF.

KULA

&&

.AVIATION...
/ISSUED 1117 AM CST TUE MAR 3 2015/
FOR 18Z TAFS...WILL CONTINUE WITH IFR/LIFR CONDITIONS DUE TO LOW
CEILINGS THROUGH THE FORECAST PERIODS FOR HSV AND MSL. FOG WILL ALSO
INCREASE WITH TIME OVERNIGHT AT BOTH TERMINALS. HAVE SHIFTED WINDS
AROUND TO THE NORTHWEST AT MSL BY THE END OF THE FORECAST PERIOD DUE
TO A COLD FRONTAL PASSAGE AND MADE PRECIP PREDOMINANT.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    60  70  29  31 /  60  80 100  50
SHOALS        60  65  27  30 /  80  80 100  50
VINEMONT      59  68  31  31 /  60  70 100  60
FAYETTEVILLE  59  63  25  28 /  70  80 100  50
ALBERTVILLE   57  69  34  33 /  60  70 100  60
FORT PAYNE    57  68  35  34 /  60  70 100  60

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR ALZ001>005.

TN...WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     AFTERNOON FOR TNZ076-096-097.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031717 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1117 AM CST TUE MAR 3 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1049 AM CST TUE MAR 3 2015/
THE 16Z SURFACE ANALYSIS INDICATED THAT THE WARM FRONT WAS STILL
SOUTH OF THE FORECAST AREA AND WAS EXTENDING WEST TO EAST ACROSS
CENTRAL ALABAMA. TEMPS ACROSS THE FORECAST AREA WERE IN THE UPPER 40S
IN SOUTHERN MIDDLE TENNESSEE...TO THE LOW TO MID 50S IN NORTHERN
ALABAMA. EXPECT THAT THE WARM FRONT WILL MOVE NORTHWARD INTO THE
FORECAST AREA BY LATE AFTERNOON AND TOWARD 00Z. DUE TO LOW CLOUDS
AND SCATTERED LIGHT SHOWERS EXPECTED...WILL KEEP TEMPS AT OR JUST
SLIGHTLY ABOVE GUIDANCE VALUES FOR AFTERNOON HIGHS. HAVE LOWERED
PRECIP CHANCES JUST SLIGHTLY DOWNWARD INTO THE CHANCE CATEGORY. WILL
BE ISSUING THE UPDATE SHORTLY.

TT

&&

.AVIATION...
FOR 18Z TAFS...WILL CONTINUE WITH IFR/LIFR CONDITIONS DUE TO LOW
CEILINGS THROUGH THE FORECAST PERIODS FOR HSV AND MSL. FOG WILL ALSO
INCREASE WITH TIME OVERNIGHT AT BOTH TERMINALS. HAVE SHIFTED WINDS
AROUND TO THE NORTHWEST AT MSL BY THE END OF THE FORECAST PERIOD DUE
TO A COLD FRONTAL PASSAGE AND MADE PRECIP PREDOMINANT.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031649 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1049 AM CST TUE MAR 3 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT THE WARM FRONT WAS STILL
SOUTH OF THE FORECAST AREA AND WAS EXTENDING WEST TO EAST ACROSS
CENTRAL ALABAMA. TEMPS ACROSS THE FORECAST AREA WERE IN THE UPPER 40S
IN SOUTHERN MIDDLE TENNESSEE...TO THE LOW TO MID 50S IN NORTHERN
ALABAMA. EXPECT THAT THE WARM FRONT WILL MOVE NORTHWARD INTO THE
FORECAST AREA BY LATE AFTERNOON AND TOWARD 00Z. DUE TO LOW CLOUDS
AND SCATTERED LIGHT SHOWERS EXPECTED...WILL KEEP TEMPS AT OR JUST
SLIGHTLY ABOVE GUIDANCE VALUES FOR AFTERNOON HIGHS. HAVE LOWERED
PRECIP CHANCES JUST SLIGHTLY DOWNWARD INTO THE CHANCE CATEGORY. WILL
BE ISSUING THE UPDATE SHORTLY.

TT

&&

.AVIATION...
/ISSUED 614 AM CST TUE MAR 3 2015/
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031649 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1049 AM CST TUE MAR 3 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT THE WARM FRONT WAS STILL
SOUTH OF THE FORECAST AREA AND WAS EXTENDING WEST TO EAST ACROSS
CENTRAL ALABAMA. TEMPS ACROSS THE FORECAST AREA WERE IN THE UPPER 40S
IN SOUTHERN MIDDLE TENNESSEE...TO THE LOW TO MID 50S IN NORTHERN
ALABAMA. EXPECT THAT THE WARM FRONT WILL MOVE NORTHWARD INTO THE
FORECAST AREA BY LATE AFTERNOON AND TOWARD 00Z. DUE TO LOW CLOUDS
AND SCATTERED LIGHT SHOWERS EXPECTED...WILL KEEP TEMPS AT OR JUST
SLIGHTLY ABOVE GUIDANCE VALUES FOR AFTERNOON HIGHS. HAVE LOWERED
PRECIP CHANCES JUST SLIGHTLY DOWNWARD INTO THE CHANCE CATEGORY. WILL
BE ISSUING THE UPDATE SHORTLY.

TT

&&

.AVIATION...
/ISSUED 614 AM CST TUE MAR 3 2015/
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 031649 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1049 AM CST TUE MAR 3 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT THE WARM FRONT WAS STILL
SOUTH OF THE FORECAST AREA AND WAS EXTENDING WEST TO EAST ACROSS
CENTRAL ALABAMA. TEMPS ACROSS THE FORECAST AREA WERE IN THE UPPER 40S
IN SOUTHERN MIDDLE TENNESSEE...TO THE LOW TO MID 50S IN NORTHERN
ALABAMA. EXPECT THAT THE WARM FRONT WILL MOVE NORTHWARD INTO THE
FORECAST AREA BY LATE AFTERNOON AND TOWARD 00Z. DUE TO LOW CLOUDS
AND SCATTERED LIGHT SHOWERS EXPECTED...WILL KEEP TEMPS AT OR JUST
SLIGHTLY ABOVE GUIDANCE VALUES FOR AFTERNOON HIGHS. HAVE LOWERED
PRECIP CHANCES JUST SLIGHTLY DOWNWARD INTO THE CHANCE CATEGORY. WILL
BE ISSUING THE UPDATE SHORTLY.

TT

&&

.AVIATION...
/ISSUED 614 AM CST TUE MAR 3 2015/
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 031649 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1049 AM CST TUE MAR 3 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT THE WARM FRONT WAS STILL
SOUTH OF THE FORECAST AREA AND WAS EXTENDING WEST TO EAST ACROSS
CENTRAL ALABAMA. TEMPS ACROSS THE FORECAST AREA WERE IN THE UPPER 40S
IN SOUTHERN MIDDLE TENNESSEE...TO THE LOW TO MID 50S IN NORTHERN
ALABAMA. EXPECT THAT THE WARM FRONT WILL MOVE NORTHWARD INTO THE
FORECAST AREA BY LATE AFTERNOON AND TOWARD 00Z. DUE TO LOW CLOUDS
AND SCATTERED LIGHT SHOWERS EXPECTED...WILL KEEP TEMPS AT OR JUST
SLIGHTLY ABOVE GUIDANCE VALUES FOR AFTERNOON HIGHS. HAVE LOWERED
PRECIP CHANCES JUST SLIGHTLY DOWNWARD INTO THE CHANCE CATEGORY. WILL
BE ISSUING THE UPDATE SHORTLY.

TT

&&

.AVIATION...
/ISSUED 614 AM CST TUE MAR 3 2015/
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031214
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
614 AM CST TUE MAR 3 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 414 AM CST TUE MAR 3 2015/

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 031214
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
614 AM CST TUE MAR 3 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 414 AM CST TUE MAR 3 2015/

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031214
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
614 AM CST TUE MAR 3 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 414 AM CST TUE MAR 3 2015/

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031214
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
614 AM CST TUE MAR 3 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 414 AM CST TUE MAR 3 2015/

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...IFR STRATUS CIGS ARND 600 FT PREVAIL AT THE MSL/HSV
TERMINALS THIS MORNING...WITH VSBY RANGING FROM 2-6 SM. EXPECT
THESE CONDS TO CONTINUE THRU 03/17Z...ALONG WITH A LGT SE FLOW AND
PATCHY -DZ. WARM FRONT WILL LIFT NWD LATE THIS MORNING...WITH A MINOR
IMPROVEMENT IN CIGS BUT A MORE NOTICEABLE IMPROVEMENT IN VSBY AS
WINDS INCREASE FROM THE SSE. SHRA WILL BE PSBL THIS AFTN...BUT SCT
NATURE OF COVERAGE ONLY WARRANTS A VCSH ATTM. STRONGER SSW FLOW OF
10-15 KTS WILL DEVELOP BY 04/02Z AND LEAD TO A MORE WIDESPREAD
COVERAGE OF SHRA...WITH TEMPO INCLUDED BTWN 04/02-06Z. DESPITE THE
ELEVATED SSW FLOW...PREVAILING MVFR VSBY IS EXPECTED BTWN 08-12Z
ALONG WITH A CONTINUATION OF IFR CIGS ARND 600 FT.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 031014
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
414 AM CST TUE MAR 3 2015

.DISCUSSION...

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
/ISSUED 1114 PM CST MON MAR 2 2015/
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    64  59  63  27 /  60  50  80 100
SHOALS        66  58  61  26 /  60  60  80 100
VINEMONT      64  57  64  27 /  60  50  70 100
FAYETTEVILLE  62  57  58  24 /  60  60  80 100
ALBERTVILLE   63  56  65  31 /  60  40  70 100
FORT PAYNE    59  57  65  31 /  70  40  70 100

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031014
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
414 AM CST TUE MAR 3 2015

.DISCUSSION...

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
/ISSUED 1114 PM CST MON MAR 2 2015/
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    64  59  63  27 /  60  50  80 100
SHOALS        66  58  61  26 /  60  60  80 100
VINEMONT      64  57  64  27 /  60  50  70 100
FAYETTEVILLE  62  57  58  24 /  60  60  80 100
ALBERTVILLE   63  56  65  31 /  60  40  70 100
FORT PAYNE    59  57  65  31 /  70  40  70 100

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 031014
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
414 AM CST TUE MAR 3 2015

.DISCUSSION...

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
/ISSUED 1114 PM CST MON MAR 2 2015/
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    64  59  63  27 /  60  50  80 100
SHOALS        66  58  61  26 /  60  60  80 100
VINEMONT      64  57  64  27 /  60  50  70 100
FAYETTEVILLE  62  57  58  24 /  60  60  80 100
ALBERTVILLE   63  56  65  31 /  60  40  70 100
FORT PAYNE    59  57  65  31 /  70  40  70 100

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 031014
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
414 AM CST TUE MAR 3 2015

.DISCUSSION...

ZONAL FLOW PERSISTS IN THE LOW TO MID LEVELS ACROSS THE
SOUTHEAST...WHILE A DEEP UPPER LEVEL CLOSED LOW SITS OVER CANADA AND
A SECOND LOW SITS OFF THE COAST OF CALIFORNIA. AT THE SURFACE...THE
COLD FRONT THAT MOVED THROUGH YESTERDAY MORNING IS CURRENTLY STALLED
ACROSS SOUTHERN GEORGIA AND SOUTHERN ALABAMA...WHILE THE SURFACE
HIGH HAS MOVED NORTHEAST..WITH THE CENTER OVER PENNSYLVANIA. AS THIS
HIGH CONTINUES TO PUSH EAST...WINDS WILL BEGIN TO SHIFT MORE
SOUTHERLY...WITH THE STALLED FRONT EXPECTED TO LIFT NORTHWARD
THROUGH THE DAY. THE UPPER TROUGH WILL BEGIN TO MOVE ASHORE LATER
THIS MORNING...WITH WEAK UPPER LEVEL RIDGING EXPECTED TO BUILD OVER
THE SOUTHEAST. THIS WILL SET THE AREA UP FOR A PERIOD OF VERY STRONG
DEEP LAYER WAA OVER THE NEXT 24 HOURS. TEMPERATURES CURRENTLY IN THE
MID TO UPPER 40S WILL RISE AT LEAST 15 DEGREES BY THE
AFTERNOON...AND HIGHS IN THE UPPER 60S ARE LIKELY. SHOWERS WILL BE
POSSIBLE DURING THE DAY...AS THE WARM FRONT LIFTS
NORTHWARD...HOWEVER THUNDERSTORMS LOOK TO BE MINIMAL GIVEN THE LACK
OF INSTABILITY...DUE TO THE VERY POOR LAPSE RATES IN THE LOW TO MID
LEVELS.

THE PRIMARY FOCUS CONTINUES TO BE ON THE STRONG COLD FRONT THAT WILL
BE MOVING THROUGH THE AREA ON WEDNESDAY. THE CLOSED LOW OVER CANADA
WILL MOVE SOUTHEAST...WHILE THE CLOSED LOW OFF THE CALIFORNIA COAST
CONTINUES TO MOVE EAST THROUGH THE DESERT SOUTHWEST. A STRONG COLD
FRONT DEVELOPS SOUTH OF THE PARENT SURFACE LOW THAT WILL PUSH EAST
OVER THE GREAT LAKES LATER THIS EVENING. AS THE COLD FRONT INCHES
CLOSER TO THE AREA...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
WEDNESDAY MORNING AHEAD OF THE COLD FRONT. TEMPERATURES WILL REMAIN
IN THE UPPER 50S TO LOWER 60S...SO AN ISOLATED STRONG STORM IS
POSSIBLE...HOWEVER THE THREAT FOR ANY WIDESPREAD STRONG TO SEVERE
STORMS IS VERY LIMITED. MODEL CONSENSUS IS COMING MORE IN LINE WITH
THE TIMING OF THE COLD FRONT...HOWEVER THERE ARE STILL SOME
DISCREPANCIES...WHICH MAKES FOR A VERY DIFFICULT AND UNCERTAIN
FORECAST.

STRONG SOUTHERLY FLOW WILL CONTINUE AHEAD OF THE COLD FRONT...AND
THE FRONT MAY HAVE A DIFFICULT TIME OVERCOMING THE WARM AIRMASS IN
PLACE. WITH THAT SAID...HAVE DECIDED TO CONTINUE WITH A BLEND OF THE
GFS AND THE ECMWF...WITH FRONTAL PASSAGE OCCURRING DURING THE
AFTERNOON ACROSS THE NORTHWEST...AND CLEARING THE AREA JUST BEFORE
MIDNIGHT. AS STATED ABOVE..MODELS ARE INDICATING THAT THE COLD ARCTIC
AIR MAY HAVE A HARD TIME FILTERING INTO THE FORECAST AREA...EVEN
AFTER FRONTAL PASSAGE. AN ABUNDANCE OF MOISTURE WILL BE LOCATED JUST
AHEAD AND BEHIND THE FRONT...WITH A VERY STRONG UPPER LEVEL JET
PROVIDING CONTINUED LIFT ACROSS THE AREA. THEREFORE WIDESPREAD
SHOWERS WILL BE ONGOING THROUGH MUCH OF THE DAY AND OVERNIGHT PERIOD
WEDNESDAY INTO THURSDAY. THE QUESTION REMAINS...HOW QUICKLY WILL THE
COLDER AIR MOVE IN? GIVEN THE LATEST GUIDANCE...TEMPERATURES WILL
LIKELY REMAIN ABOVE FREEZING FOR MUCH OF THE AREA UNTIL AROUND 06Z.
SO HAVE PUSHED BACK THE TIMING OF WHEN THE RAIN WILL TRANSITION TO
FREEZING RAIN UNTIL AFTER 06Z. TEMPERATURES WILL CONTINUE TO COOL
ACROSS THE AREA...WITH THE TRANSITION OF RAIN TO FROZEN PRECIP
OCCURRING THROUGH 09Z. BY 09Z...AREAS ACROSS THE NORTHWEST WILL
LIKELY SEE A TRANSITION FROM FREEZING RAIN TO SLEET...WHILE THE
REMAINING HALF OF THE FORECAST AREA EXPERIENCES FREEZING RAIN.

THE DURATION OF FROZEN PRECIP...ALONG WITH THE FORECAST QPF WILL
STILL LEAD TO ABOUT 6 HOURS OF FREEZING RAIN FOR THE AREA. ICE
ACCUMULATION AMOUNTS OF UP TO A QUARTER OF AN INCH ARE
POSSIBLE...WITH THE GREATEST AMOUNT ACROSS THE NORTHWEST. THE
BIGGEST CHANGE FROM THE PREVIOUS FORECAST IS THE AMOUNT OF SNOW
ACCUMULATIONS. GIVEN THE LATER TIMING OF THE FREEZING
TEMPERATURES...MODELS AGREE THAT THE WARM NOSE ALOFT WILL BE SLOW TO
ERODE...THEREFORE FREEZING RAIN WILL CONTINUE TO BE THE DOMINANT
PRECIP TYPE THROUGH 12Z. AFTER 12Z ON THURSDAY...ENOUGH MOISTURE
WILL BE LEFT IN PLACE TO WARRANT LIGHT QPF AMOUNTS...AND THE ENTIRE
VERTICAL TEMPERATURE PROFILE FINALLY DROPS BELOW FREEZING...SO THERE
WILL BE A FEW LINGERING SNOW SHOWERS. MOST LOCATIONS WILL RECEIVE
ONLY A DUSTING OF SNOW...HOWEVER LOCATIONS ACROSS THE CENTRAL
PORTION OF THE FORECAST AREA MAY SEE UP TO HALF AN INCH.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY...WITH HIGH
TEMPERATURES ONLY REACHING INTO THE LOWER 30S. A DRY FORECAST IS IN
STORE FOR THE EXTENDED...WITH ONLY SCATTERED SHOWERS POSSIBLE TOWARD
THE LATTER PART OF THE FORECAST PERIOD.

73

&&

.AVIATION...
/ISSUED 1114 PM CST MON MAR 2 2015/
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    64  59  63  27 /  60  50  80 100
SHOALS        66  58  61  26 /  60  60  80 100
VINEMONT      64  57  64  27 /  60  50  70 100
FAYETTEVILLE  62  57  58  24 /  60  60  80 100
ALBERTVILLE   63  56  65  31 /  60  40  70 100
FORT PAYNE    59  57  65  31 /  70  40  70 100

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 030514
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1114 PM CST MON MAR 2 2015

.UPDATE...
FOR 06Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 952 PM CST MON MAR 2 2015/
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z AS A WARM FRONT
MOVES NORTH...SO WILL KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD
ATTM.

07

&&

.AVIATION...
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 030514
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1114 PM CST MON MAR 2 2015

.UPDATE...
FOR 06Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 952 PM CST MON MAR 2 2015/
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z AS A WARM FRONT
MOVES NORTH...SO WILL KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD
ATTM.

07

&&

.AVIATION...
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 030514
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1114 PM CST MON MAR 2 2015

.UPDATE...
FOR 06Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 952 PM CST MON MAR 2 2015/
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z AS A WARM FRONT
MOVES NORTH...SO WILL KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD
ATTM.

07

&&

.AVIATION...
FOR 06Z TAFS...SCATTERED SHOWERS HAVE ENDED OVER THE TAF SITES ATTM.
HOWEVER AS A WARM FRONT MOVES NORTH TONIGHT EXPECT MORE SCT SHOWERS
TO DEVELOP ACROSS THE TN VALLEY. THERE COULD BE A FEW TSRA TUESDAY
AFTN/EVENING AS A STRONG CDFNT EDGES CLOSER TO THE CWA. OTHERWISE
MVFR/IFR CONDITIONS ARE EXPECTED THRU THE FCST PERIOD.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 030357
AFDHUN

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z AS A WARM FRONT
MOVES NORTH...SO WILL KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD
ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 030357
AFDHUN

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z AS A WARM FRONT
MOVES NORTH...SO WILL KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD
ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 030352
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z...SO WILL
KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 030352
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z...SO WILL
KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 030352
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z...SO WILL
KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 030352
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
952 PM CST MON MAR 2 2015

.UPDATE...
NO CHANGES TO FCST ATTM.

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
UNDER CLOUDY SKIES AND A FEW ISOLATED SHRA...TEMPS WERE IN THE
LOW/MID 40S. FOR THE REST OF TONIGHT EXPECT TEMPS TO HOLD STEADY OR
EVEN RISE A FEW DEGREES THANKS TO LIGHT SE WINDS. THOUGHT ABOUT
LOWERING POPS FOR OVERNIGHT BASED ON CURRENT RADAR TRENDS BUT NEW NAM
DATA SHOWS THAT MORE SHRA WILL LIKELY REDEVELOP ARND 09Z...SO WILL
KEEP CURRENT LIKELY POPS. OTHERWISE FCST LOOKS GOOD ATTM.

07

&&

.AVIATION...
/ISSUED 547 PM CST MON MAR 2 2015/
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.PREV DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 022347
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
547 PM CST MON MAR 2 2015

.UPDATE...
FOR 00Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 022347
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
547 PM CST MON MAR 2 2015

.UPDATE...
FOR 00Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 022347
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
547 PM CST MON MAR 2 2015

.UPDATE...
FOR 00Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 022347
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
547 PM CST MON MAR 2 2015

.UPDATE...
FOR 00Z TAFS

&&

.SYNOPSIS...
/ISSUED 354 PM CST MON MAR 2 2015/

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...
/ISSUED 354 PM CST MON MAR 2 2015/

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
FOR 00Z TAFS...AN ADVANCING WARM FRONT WILL KEEP THE CHC OF SCT SHRA
OVERNIGHT ACROSS THE TAF SITES. AS THE WARM FRONT MOVES NORTH OF THE
CWA (AFTER 12Z TUESDAY) THERE WILL BE ENOUGH INSTABILITY FOR A FEW
TSRA TUESDAY AFTN. OTHERWISE EXPECT MAINLY MVFR AND IFR CONDITIONS
THRU THE FCST PERIOD FOR BOTH KHSV AND KMSL.

07

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 022154
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
354 PM CST MON MAR 2 2015

.SYNOPSIS...

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
/ISSUED 1117 AM CST MON MAR 2 2015/
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    45  66  59  62 /  70  60  80  90
SHOALS        43  67  59  60 /  60  60  80  90
VINEMONT      45  66  59  63 /  70  60  80  80
FAYETTEVILLE  42  64  57  57 /  60  60  80  90
ALBERTVILLE   47  66  59  66 /  70  60  80  80
FORT PAYNE    45  61  58  64 /  70  70  80  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 022154
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
354 PM CST MON MAR 2 2015

.SYNOPSIS...

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
/ISSUED 1117 AM CST MON MAR 2 2015/
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    45  66  59  62 /  70  60  80  90
SHOALS        43  67  59  60 /  60  60  80  90
VINEMONT      45  66  59  63 /  70  60  80  80
FAYETTEVILLE  42  64  57  57 /  60  60  80  90
ALBERTVILLE   47  66  59  66 /  70  60  80  80
FORT PAYNE    45  61  58  64 /  70  70  80  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 022154
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
354 PM CST MON MAR 2 2015

.SYNOPSIS...

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
/ISSUED 1117 AM CST MON MAR 2 2015/
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    45  66  59  62 /  70  60  80  90
SHOALS        43  67  59  60 /  60  60  80  90
VINEMONT      45  66  59  63 /  70  60  80  80
FAYETTEVILLE  42  64  57  57 /  60  60  80  90
ALBERTVILLE   47  66  59  66 /  70  60  80  80
FORT PAYNE    45  61  58  64 /  70  70  80  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 022154
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
354 PM CST MON MAR 2 2015

.SYNOPSIS...

A VERY ACTIVE WEATHER PATTERN IS SHAPING UP AS A POSITIVELY TILTED
UPPER TROUGH OFF THE S CALIFORNIA COASTLINE SLOWLY TRANSLATES
EASTWARD OVER THE NEXT FEW DAYS. IN THE MIDST OF ITS TRANSITIONING
MOVEMENT AND ORIENTATION, SUBTROPICAL JET HAS BEEN INDUCED ON ITS
SOUTHERN FLANK. WITH A JET STREAK ORIENTED N-S FROM BAJA CALIFORNIA
TO THE CENTRAL PLAINS AND THEN W-E ORIENTATION FROM THE CENTRAL
PLAINS TO THE DELMARVA COAST.

THE PROGRESSION OF THIS TROUGH IS BEING CLOSELY WATCHED AS IT
INDUCES STRONG WAA ON TUESDAY INTO WEDNESDAY. THIS COULD MEAN STRONG
AND VERY ISOLATED SEVERE THUNDERSTORMS POSSIBLE ON TUESDAY INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THEN, A VERY COLD ARCTIC AIRMASS
LOOKS TO DROP SE ACROSS THE PLAINS INTO THE TN VALLEY AS THE TROUGH
GAINS MOMENTUM AND MERGES WITH A POLAR JET MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE MIDWEST. THE COMBINATION OF THE SFC AND
UPPER LEVEL FEATURES COULD LEAD TO THE POTENTIAL FOR SIGNIFICANT
WINTER WEATHER IMPACTS ON WEDNESDAY NIGHT INTO THURSDAY.

THERE IS LOW CONFIDENCE ON PLACEMENT OF EXACT WINTRY PRECIP ACCUMULATIONS
RIGHT NOW AND CHANGES TO THE PRECIP TYPE/ACCUMULATION TIMING IS
LIKELY IN THE FOLLOWING FORECASTS.

SL.77

&&

.DISCUSSION...

THOUGH MOST OF THE ATTENTION HAS BEEN PLACED ON THE ABOVE POSSIBLE
IMPACTS THAT ARE LIKELY ACROSS THE TN VALLEY, FOR TONIGHT, SHOWERS
WILL OVERSPREAD THE REGION AS A WARM FRONT LIFTS NORTH TONIGHT.
THERE IS WEAK ELEVATED INSTABILITY (MUCAPES OF 100-200 J/KG) PRESENT
DURING THE EARLY MORNING HOURS ON TUESDAY THAT MAY TRANSLATE TO
UPDRAFTS STRENGTHENING AND RESULTING IN THUNDERSTORMS. THUS, WILL
KEEP THUNDERSTORMS IN THE FORECAST FOR LATE TONIGHT INTO EARLY
TOMORROW MORNING. AN ADDED BONUS FOR TOMORROW IS WARMER DAYTIME
TEMPERATURES AS THE WARM FRONT PASSAGE PLACES THE TN VALLEY INTO THE
WARM SECTOR AND WAA CONTINUES.

AS THE UPPER TROUGH MOVES CLOSER, A VERY STRONG UPPER JET STREAK
WILL SETUP TO THE NORTH OVER THE MID-UPPER MS RIVER VALLEY INDUCING
A LLJ OF 50-60 KTS ON TUESDAY MORNING. TEMPERATURES WILL LIKELY TOP
OUT IN THE MID TO UPPER 60S ON TUESDAY AFTERNOON. WITH THE STRONG
WAA AND SATURATED PROFILE ALOFT, WAA SHOWERS AND THUNDERSTORMS ARE
POSSIBLE WITHIN THE WARM SECTOR. HOWEVER, THE HIGHEST THREAT WILL
ACTUALLY BE DURING TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER JET
MOVES CLOSER AND WIND SHEAR INCREASES SUBSTANTIALLY. SRH VALUES ARE
OFF THE CHARTS WITH SOME MODEL RUNS (VALUES BTWN 300-600 M2/S2 AT
0-3 KM). INSTABILITY VALUES LOOK TO BE RATHER PALTRY (BTWN 50-200
J/KG). WITH THESE VALUES, IT APPEARS WE WILL HAVE A THREAT FOR A QLCS
DEVELOPING AHEAD OF THE SLOW MOVING COLD FRONT WITH DAMAGING WINDS
AND SPIN-UP TORNADOES THE PRIMARY THREATS.

THE MED RANGE MODELS HAVE BEEN SHOWING A GENERALLY SLOWER TREND IN
THE MOVEMENT OF THE TROUGH AND ACCOMPANYING SFC COLD FRONT FOR
WEDNESDAY THROUGH THURSDAY. THIS IS TO BE EXPECTED GIVEN THE COMPLEX
MOVEMENT AND CHANGE IN ORIENTATION OF THE TROUGH. THIS HAS
INTRODUCED ANOTHER LAYER OF COMPLEXITY AS THE PRECIP TYPE FOLLOWS
THE FRONT AND EVENTUALLY CAA BEGINS ALOFT. THUS, HAVE MADE
ADJUSTMENTS TO KEEP SOUTHERN PORTIONS OF THE CWA WARMER ON WEDNESDAY
WITH THE POSSIBILITY OF HIGHS ACTUALLY OCCURRING DURING THE DAYTIME
(AS OPPOSED TO ORIGINALLY THOUGHT IN THE EARLY MORNING TIME). THIS
HAS ALSO PUSHED BACK THE TRANSITION FROM SHOWERS/THUNDERSTORMS EARLY
WEDNESDAY MORNING TO ALL RAIN ALONG WITH THE CHANGE IN WINTRY
PRECIPITATION. A SIGNIFICANT WARM NOSE IS SEEN IN ALL OF THE MODEL
RUNS WITH A PRONOUNCED SHALLOW INVERSION INDICATIVE OF THE ARCTIC
FRONT. EVEN WITH THIS, THE SFC TEMPS LOOK TO BE SLOWER TO DROP BELOW
FREEZING DURING THE DAY ON WEDNESDAY EVENING. FORECAST SOUNDINGS
SHOW THAT SIGNIFICANT COLD AIR ADVECTION EXISTS BELOW AN OVERRUNNING
AREA OF STRONG MID-LEVEL WARM AIR ADVECTION (SW FLOW ALOFT). IN
ADDITION, OVERRUNNING MID-LEVEL SHORTWAVE TROUGHS MOVING ALONG THE
SW FLOW ALOFT ATOP A SATURATED COLUMN COULD YIELD SIGNIFICANT ICE
ACCUMULATIONS. WITH THE TIMING AND OVERALL SETUP OF FORECAST QPF,
HAVE MADE ADJUSTMENTS TO THE FORECAST TO REFLECT A SLOWER TRANSITION
TO FREEZING RAIN ON WEDNESDAY EVENING OVER FAR NW AL. SO, GIVEN ALL
OF THAT, THE WINTRY PRECIPITATION STARTS AFTER 00Z OVER FAR NW AL/S
MIDDLE TN AS FREEZING RAIN FOLLOWED BY A FREEZING RAIN/SLEET MIX
AFTER 06Z WITH A SLOW TRANSITION TO SNOW/SLEET AFTER 09-12Z. THIS
PRECIP TYPE TRANSITION SHOULD SLOWLY PROGRESS ACROSS THE ENTIRE TN
VALLEY OVERNIGHT.

ACCUMULATIONS ARE DIFFICULT TO DETERMINE WITH THE VERY WARM SFC
TEMPS IN PLACE JUST PRIOR TO THE FRONTAL PASSAGE. IN FACT, ICE
ACCUMULATIONS MAY ACTUALLY START ON ELEVATED SURFACES AND VEGETATION
FIRST BEFORE GRADUALLY IMPACTING THE ROADS OVERNIGHT WEDNESDAY NIGHT
INTO THURSDAY MORNING. SO, FOR NOW, HAVE INCLUDED A SHARP GRADIENT
IN SNOWFALL ACCUMULATIONS ACROSS THE ENTIRE CWA WITH A MAXIMUM OVER
NW AL/S MIDDLE TN GIVEN THE ORIENTATION OF THE MAX QPF FORECAST AND
PROFILE COOLING TIMING. ICE AMOUNTS UP TO 0.3 INCHES AND SNOWFALL
FROM 0.5-2.0 INCHES ARE LIKELY.

THEN, BY THURSDAY MORNING, TEMPERATURES ARE EXPECTED TO BE STARTING
IN THE LOW TO MID 20S WITH HIGHS ONLY EXPECTED TO RISE CLOSE TO 30-
32 DEGREES. COMBINE THESE TEMPERATURES WITH NORTHERLY WINDS OF 10-15
MPH AND ICING ON VEGETATION AND ROADS, AND THERE VERY WELL COULD BE
SIGNIFICANT HAZARDOUS TRAVEL AND TREE DAMAGE.

TEMPERATURES FINALLY RISE BACK ABOVE FREEZING ON FRIDAY AS ZONAL
FLOW RETURNS. SOUTHERLY FLOW RETURNS ON SATURDAY WITH TEMPS RISING
INTO THE 50S BY THEN AND AGAIN ON SUNDAY.

SL.77

&&

.AVIATION...
/ISSUED 1117 AM CST MON MAR 2 2015/
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    45  66  59  62 /  70  60  80  90
SHOALS        43  67  59  60 /  60  60  80  90
VINEMONT      45  66  59  63 /  70  60  80  80
FAYETTEVILLE  42  64  57  57 /  60  60  80  90
ALBERTVILLE   47  66  59  66 /  70  60  80  80
FORT PAYNE    45  61  58  64 /  70  70  80  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021717 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1117 AM CST MON MAR 2 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1050 AM CST MON MAR 2 2015/
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 021717 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1117 AM CST MON MAR 2 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1050 AM CST MON MAR 2 2015/
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021717 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1117 AM CST MON MAR 2 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1050 AM CST MON MAR 2 2015/
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 021717 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1117 AM CST MON MAR 2 2015

.UPDATE...
FOR 18Z TAFS

&&

.DISCUSSION...
/ISSUED 1050 AM CST MON MAR 2 2015/
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
FOR 18Z TAFS...WILL CONTINUE WITH MVFR BASED CEILINGS FOR HSV AND MSL
UNTIL AROUND 03Z. IFR CEILING CONDITIONS ARE THEN EXPECTED THROUGH
THE REST OF THE FORECAST PERIOD AT HSV AND MSL. HAVE ALSO SLOWLY
BROUGHT IN VISIBILITIES IN THE MVFR RANGE AFTER 08Z AT BOTH LOCATIONS
AND PREDOMINANT LIGHT RAIN AFTER 14Z.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021650 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1050 AM CST MON MAR 2 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
/ISSUED 604 AM CST MON MAR 2 2015/
FOR 12Z TAFS...COLD FRONT HAS PUSHED SOUTH OF BOTH HSV/MSL WITH NNE
FLOW OF 10G18 KTS EXPECTED TO PERSIST THROUGH 02/15Z...ALONG WITH
IFR CIGS AND MVFR VSBY REDUCTIONS IN -DZ/BR. WEAK MIXING IN WAKE OF
FRONT AND DRIER AIRMASS MOVING INTO THE REGION SHOULD ALLOW VSBY TO
IMPROVE AND CIGS TO LIFT INTO THE 1500-2500 FT RANGE BY 15Z...AS
WINDS DIMINISH AND VEER TO ENE. THREAT FOR SHRA MAY INCREASE ONCE
AGAIN BY 21Z AS A WEAK UPPER AIR DISTURBANCE APPROACHES...ALTHOUGH
GIVEN SCT COVERAGE EXPECT CIGS TO REMAIN MVFR UNTIL LOW-LEVEL FLOW
VEERS TO ESE ARND 03/03Z. WINDS WILL INCREASE AND SHIFT TO SSE BY 08Z
AS WARM FRONT MOVES NWD...WITH MVFR VSBY REDUCTIONS IN BR PSBL BEYOND
THIS POINT. THREAT FOR SCT SHRA WILL CONTINUE OVERNIGHT... WITH A FEW
STORMS ALSO PSBL. HOWEVER...THREAT FOR TSRA IS TOO LOW TO MENTION IN
TAF ATTM.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 021650 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1050 AM CST MON MAR 2 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
/ISSUED 604 AM CST MON MAR 2 2015/
FOR 12Z TAFS...COLD FRONT HAS PUSHED SOUTH OF BOTH HSV/MSL WITH NNE
FLOW OF 10G18 KTS EXPECTED TO PERSIST THROUGH 02/15Z...ALONG WITH
IFR CIGS AND MVFR VSBY REDUCTIONS IN -DZ/BR. WEAK MIXING IN WAKE OF
FRONT AND DRIER AIRMASS MOVING INTO THE REGION SHOULD ALLOW VSBY TO
IMPROVE AND CIGS TO LIFT INTO THE 1500-2500 FT RANGE BY 15Z...AS
WINDS DIMINISH AND VEER TO ENE. THREAT FOR SHRA MAY INCREASE ONCE
AGAIN BY 21Z AS A WEAK UPPER AIR DISTURBANCE APPROACHES...ALTHOUGH
GIVEN SCT COVERAGE EXPECT CIGS TO REMAIN MVFR UNTIL LOW-LEVEL FLOW
VEERS TO ESE ARND 03/03Z. WINDS WILL INCREASE AND SHIFT TO SSE BY 08Z
AS WARM FRONT MOVES NWD...WITH MVFR VSBY REDUCTIONS IN BR PSBL BEYOND
THIS POINT. THREAT FOR SCT SHRA WILL CONTINUE OVERNIGHT... WITH A FEW
STORMS ALSO PSBL. HOWEVER...THREAT FOR TSRA IS TOO LOW TO MENTION IN
TAF ATTM.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021650 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1050 AM CST MON MAR 2 2015

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...
THE 16Z SURFACE ANALYSIS INDICATED THAT A WEAK TROUGH WAS SITUATED
ALONG THE SOUTHERN PORTION OF THE FORECAST AREA. TEMPS WERE RANGING
FROM THE MID TO UPPER 30S ACROSS SOUTHERN MIDDLE TENNESSEE AND ALONG
THE BORDERING ALABAMA COUNTIES...TO THE 40 TO 45 DEGREE RANGE ACROSS
CULLMAN...MARSHALL AND INTO DEKALB COUNTIES. THE SHORT TERM MODELS
KEEP THE BOUNDARY NEARLY STATIONARY ACROSS THE REGION THROUGH THE
AFTERNOON. WILL CONTINUE TO MONITOR TSRA POTENTIAL ALONG THE BOUNDARY
THROUGH THE AFTERNOON. MOST OF THE ACTIVITY SHOULD REMAIN SOUTH OF
THE FORECAST AREA...BUT CULLMAN COUNTY COULD BE ON THE NORTHERN
FRINGE OF THIS AREA OF SHOWERS/EMBEDDED THUNDER. TEMPS SHOULD ONLY
RISE A FEW DEGREES THIS AFTERNOON IN THE WEAK COLD ADVECTION ACROSS
THE AREA. HAVE MADE LITTLE CHANGES TO THE AFTERNOON FORECAST.

TT

&&

.AVIATION...
/ISSUED 604 AM CST MON MAR 2 2015/
FOR 12Z TAFS...COLD FRONT HAS PUSHED SOUTH OF BOTH HSV/MSL WITH NNE
FLOW OF 10G18 KTS EXPECTED TO PERSIST THROUGH 02/15Z...ALONG WITH
IFR CIGS AND MVFR VSBY REDUCTIONS IN -DZ/BR. WEAK MIXING IN WAKE OF
FRONT AND DRIER AIRMASS MOVING INTO THE REGION SHOULD ALLOW VSBY TO
IMPROVE AND CIGS TO LIFT INTO THE 1500-2500 FT RANGE BY 15Z...AS
WINDS DIMINISH AND VEER TO ENE. THREAT FOR SHRA MAY INCREASE ONCE
AGAIN BY 21Z AS A WEAK UPPER AIR DISTURBANCE APPROACHES...ALTHOUGH
GIVEN SCT COVERAGE EXPECT CIGS TO REMAIN MVFR UNTIL LOW-LEVEL FLOW
VEERS TO ESE ARND 03/03Z. WINDS WILL INCREASE AND SHIFT TO SSE BY 08Z
AS WARM FRONT MOVES NWD...WITH MVFR VSBY REDUCTIONS IN BR PSBL BEYOND
THIS POINT. THREAT FOR SCT SHRA WILL CONTINUE OVERNIGHT... WITH A FEW
STORMS ALSO PSBL. HOWEVER...THREAT FOR TSRA IS TOO LOW TO MENTION IN
TAF ATTM.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021204
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
604 AM CST MON MAR 2 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 500 AM CST MON MAR 2 2015/

WATER VAPOR IMAGERY SHOWS MUCH OF THE AREA UNDER ZONAL FLOW
ALOFT. AT THE SURFACE...LIGHT RAIN CONTINUES TO MOVE EAST ACROSS THE
FORECAST AREA...BEHIND A SURFACE COLD FRONT THAT HAS PUSHED TO THE
EAST OF THE AREA. THIS FRONT IS EXPECTED TO STALL TO THE SOUTH...WITH
SHOWERS CONTINUING THROUGH THE MORNING IN RESPONSE TO SEVERAL WEAK
SHORTWAVES MOVING EAST IN THE UPPER LEVEL ZONAL FLOW. COVERAGE WILL
LIKELY DECREASE THIS AFTERNOON...AS DRIER AIR FILTERS INTO THE
REGION. HIGH PRESSURE AT THE SURFACE WILL MOVE EAST ACROSS THE GREAT
LAKES...WITH NORTHERLY WINDS SHIFTING TO THE EAST THIS EVENING. THE
AFOREMENTIONED COLD FRONT IS EXPECTED TO LIFT NORTHWARD
OVERNIGHT...WITH SHOWERS...WITH AN ISOLATED THUNDERSTORM...POSSIBLE
AFTER 06Z. ALTHOUGH SHOWERS WILL LIKELY BE ONGOING TUESDAY
MORNING...TEMPERATURES ARE EXPECTED TO WARM UP QUITE A BIT...DUE TO
THE STRONG WAA AT THE SURFACE AND A DECREASE IN RAIN COVERAGE BY THE
AFTERNOON.

THE MAIN FOCUS FOR THE FORECAST THIS MORNING CONTINUES TO BE THE
SETUP ON TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AN UPPER LEVEL
CLOSED LOW OFF OF THE SOUTHERN CALIFORNIA COAST WILL PUSH ASHORE
LATER TODAY...AS AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTHWARD OUT
OF CANADA. SURFACE CYCLOGENESIS WILL OCCUR OVER CANADA...WITH A
DEEPENING SURFACE LOW EXPECTED TO MOVE EAST ACROSS THE GREAT LAKES. A
STRONG COLD FRONT WILL DEVELOP AND DRAG SOUTHWARD FROM THE SURFACE
LOW AND MOVE THROUGH THE FORECAST AREA WEDNESDAY INTO THURSDAY.
WHILE MODEL GUIDANCE IS STILL IN GOOD AGREEMENT WITH THE OVERALL
SETUP...THE TIMING DIFFERENCES ARE STILL GLARING...WITH EACH TIMING
SCENARIO POSING A DIFFERENT SET OF THREATS FOR THE FORECAST AREA.
THIS MAKES THINGS QUITE UNCERTAIN...HOWEVER FOR NOW...HAVE GONE WITH
A BLEND OF THE GFS AND ECMWF...WITH AN EMPHASIS ON THE GFS.

AHEAD OF THE COLD FRONT...A 50-60KT LLJ WILL MOVE JUST TO THE NORTH
OF THE FORECAST AREA. SOUTHERLY FLOW AT THE SURFACE CONTINUES...WITH
HIGHS ON TUESDAY IN THE UPPER 60S...AND DEWPOINTS REACHING INTO THE
UPPER 50S. SHOWERS...WITH ISOLATED THUNDERSTORMS ARE POSSIBLE
OVERNIGHT TUESDAY AND INTO EARLY WEDNESDAY MORNING. INSTABILITY DOES
APPEAR TO BE LIMITED...GIVEN A FAIRLY STRONG CAPPING INVERSION
ADVERTISED BY MODEL SOUNDINGS. WIND SHEAR WILL BE DECENT TO SUPPORT A
FEW ORGANIZED THUNDERSTORMS...BUT GIVEN THE CURRENT SOLUTION...THERE
LOOKS TO BE ONLY A SMALL WINDOW WHERE STRONG TO SEVERE THUNDERSTORMS
WILL BE POSSIBLE...JUST AHEAD OF THE COLD FRONT. IF THE SLOWER NAM
SOLUTION PANS OUT...WE MAY HAVE MORE TIME TO WARM UP ON WEDNESDAY
AFTERNOON AND THERE WOULD BE MORE OF AN OPPORTUNITY FOR THE INVERSION
TO DIMINISH. HOWEVER...THE NAM SEEMS TO BE A BIT TOO SLOW...GIVEN THE
STRONG AIRMASS BEHIND THE FRONT.

THE COLD FRONT IS EXPECTED TO ENTER THE NORTHWEST PORTION OF THE
FORECAST AREA BY 18Z ON WEDNESDAY...AND MOVE TO THE EAST OF THE AREA
BY 00Z THURSDAY. BEHIND THE FRONT...TEMPERATURES WILL DROP
QUICKLY...WITH MUCH OF THE AREA NEAR OR BELOW FREEZING BY 00Z. THE
UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA WILL PHASE WITH THE
UPPER TROUGH OVER CANADA AND THE UPPER LEVEL JET IS EXPECTED TO
INTENSIFY SIGNIFICANTLY. THE FORECAST AREA WILL BE LOCATED IN THE
AREA OF ENHANCED LIFT...WITH AN ABUNDANCE OF MOISTURE LAGGING BEHIND
THE FRONT AS WELL. THIS SETS THE STAGE FOR ONGOING MODERATE
PRECIPITATION ACROSS THE AREA. AS TEMPERATURES FALL DURING THE
AFTERNOON...RAIN WILL TRANSITION TO FREEZING RAIN ACROSS THE
NORTHWEST...AND THEN CONTINUE TO TRANSITION ACROSS THE REST OF THE
AREA. MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF FREEZING RAIN
ACROSS MUCH OF THE AREA...WITH A BRIEF CHANGE OVER TO SLEET BY
06Z...AND THEN TO LIGHT SNOW BY 12Z. FAIRLY SIGNIFICANT ICE
ACCUMULATIONS ARE POSSIBLE...WITH MUCH OF THE AREA EXPECTED TO
RECEIVE AROUND A QUARTER OF INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THE WARM NOSE ALOFT WILL COOL FASTER ACROSS THE
NORTHWEST...WHERE A TRANSITION TO SLEET AND SNOW WILL OCCUR SOONER.
THEREFORE...IN THESE LOCATIONS...UP TO 2 INCHES OF SNOW/SLEET
ACCUMULATIONS ARE POSSIBLE. IF THE TRENDS CONTINUE...THESE AMOUNTS
MAY HAVE TO BE ADJUSTED. AGAIN...IT SHOULD BE NOTED THAT EVEN WITH
THE SLOWER MODEL SOLUTIONS...THERE WILL STILL BE THE THREAT FOR
FROZEN PRECIPITATION BEHIND THE FRONT...HOWEVER THE DURATION MAY BE
LESS.

BEYOND 12Z THURSDAY...PRECIPITATION WILL COME TO AN END FROM WEST TO
EAST AS HIGH PRESSURE BUILDS IN. TEMPERATURES WILL NOT WARM UP VERY
MUCH ON THURSDAY...WITH MOST LOCATIONS REMAINING BELOW FREEZING.
TEMPS ON FRIDAY WILL BOTTOM OUT IN THE TEENS...BEFORE WARMING INTO
THE LOWER 40S. A LIGHT WARMING TREND WILL CONTINUE THROUGH THE
EXTENDED...WITH ONLY A SLIGHT CHANCE OF RAIN EXPECTED TOWARDS THE
LATTER PART OF THE PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...COLD FRONT HAS PUSHED SOUTH OF BOTH HSV/MSL WITH NNE
FLOW OF 10G18 KTS EXPECTED TO PERSIST THROUGH 02/15Z...ALONG WITH
IFR CIGS AND MVFR VSBY REDUCTIONS IN -DZ/BR. WEAK MIXING IN WAKE OF
FRONT AND DRIER AIRMASS MOVING INTO THE REGION SHOULD ALLOW VSBY TO
IMPROVE AND CIGS TO LIFT INTO THE 1500-2500 FT RANGE BY 15Z...AS
WINDS DIMINISH AND VEER TO ENE. THREAT FOR SHRA MAY INCREASE ONCE
AGAIN BY 21Z AS A WEAK UPPER AIR DISTURBANCE APPROACHES...ALTHOUGH
GIVEN SCT COVERAGE EXPECT CIGS TO REMAIN MVFR UNTIL LOW-LEVEL FLOW
VEERS TO ESE ARND 03/03Z. WINDS WILL INCREASE AND SHIFT TO SSE BY 08Z
AS WARM FRONT MOVES NWD...WITH MVFR VSBY REDUCTIONS IN BR PSBL BEYOND
THIS POINT. THREAT FOR SCT SHRA WILL CONTINUE OVERNIGHT... WITH A FEW
STORMS ALSO PSBL. HOWEVER...THREAT FOR TSRA IS TOO LOW TO MENTION IN
TAF ATTM.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




000
FXUS64 KHUN 021204
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
604 AM CST MON MAR 2 2015

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 500 AM CST MON MAR 2 2015/

WATER VAPOR IMAGERY SHOWS MUCH OF THE AREA UNDER ZONAL FLOW
ALOFT. AT THE SURFACE...LIGHT RAIN CONTINUES TO MOVE EAST ACROSS THE
FORECAST AREA...BEHIND A SURFACE COLD FRONT THAT HAS PUSHED TO THE
EAST OF THE AREA. THIS FRONT IS EXPECTED TO STALL TO THE SOUTH...WITH
SHOWERS CONTINUING THROUGH THE MORNING IN RESPONSE TO SEVERAL WEAK
SHORTWAVES MOVING EAST IN THE UPPER LEVEL ZONAL FLOW. COVERAGE WILL
LIKELY DECREASE THIS AFTERNOON...AS DRIER AIR FILTERS INTO THE
REGION. HIGH PRESSURE AT THE SURFACE WILL MOVE EAST ACROSS THE GREAT
LAKES...WITH NORTHERLY WINDS SHIFTING TO THE EAST THIS EVENING. THE
AFOREMENTIONED COLD FRONT IS EXPECTED TO LIFT NORTHWARD
OVERNIGHT...WITH SHOWERS...WITH AN ISOLATED THUNDERSTORM...POSSIBLE
AFTER 06Z. ALTHOUGH SHOWERS WILL LIKELY BE ONGOING TUESDAY
MORNING...TEMPERATURES ARE EXPECTED TO WARM UP QUITE A BIT...DUE TO
THE STRONG WAA AT THE SURFACE AND A DECREASE IN RAIN COVERAGE BY THE
AFTERNOON.

THE MAIN FOCUS FOR THE FORECAST THIS MORNING CONTINUES TO BE THE
SETUP ON TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AN UPPER LEVEL
CLOSED LOW OFF OF THE SOUTHERN CALIFORNIA COAST WILL PUSH ASHORE
LATER TODAY...AS AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTHWARD OUT
OF CANADA. SURFACE CYCLOGENESIS WILL OCCUR OVER CANADA...WITH A
DEEPENING SURFACE LOW EXPECTED TO MOVE EAST ACROSS THE GREAT LAKES. A
STRONG COLD FRONT WILL DEVELOP AND DRAG SOUTHWARD FROM THE SURFACE
LOW AND MOVE THROUGH THE FORECAST AREA WEDNESDAY INTO THURSDAY.
WHILE MODEL GUIDANCE IS STILL IN GOOD AGREEMENT WITH THE OVERALL
SETUP...THE TIMING DIFFERENCES ARE STILL GLARING...WITH EACH TIMING
SCENARIO POSING A DIFFERENT SET OF THREATS FOR THE FORECAST AREA.
THIS MAKES THINGS QUITE UNCERTAIN...HOWEVER FOR NOW...HAVE GONE WITH
A BLEND OF THE GFS AND ECMWF...WITH AN EMPHASIS ON THE GFS.

AHEAD OF THE COLD FRONT...A 50-60KT LLJ WILL MOVE JUST TO THE NORTH
OF THE FORECAST AREA. SOUTHERLY FLOW AT THE SURFACE CONTINUES...WITH
HIGHS ON TUESDAY IN THE UPPER 60S...AND DEWPOINTS REACHING INTO THE
UPPER 50S. SHOWERS...WITH ISOLATED THUNDERSTORMS ARE POSSIBLE
OVERNIGHT TUESDAY AND INTO EARLY WEDNESDAY MORNING. INSTABILITY DOES
APPEAR TO BE LIMITED...GIVEN A FAIRLY STRONG CAPPING INVERSION
ADVERTISED BY MODEL SOUNDINGS. WIND SHEAR WILL BE DECENT TO SUPPORT A
FEW ORGANIZED THUNDERSTORMS...BUT GIVEN THE CURRENT SOLUTION...THERE
LOOKS TO BE ONLY A SMALL WINDOW WHERE STRONG TO SEVERE THUNDERSTORMS
WILL BE POSSIBLE...JUST AHEAD OF THE COLD FRONT. IF THE SLOWER NAM
SOLUTION PANS OUT...WE MAY HAVE MORE TIME TO WARM UP ON WEDNESDAY
AFTERNOON AND THERE WOULD BE MORE OF AN OPPORTUNITY FOR THE INVERSION
TO DIMINISH. HOWEVER...THE NAM SEEMS TO BE A BIT TOO SLOW...GIVEN THE
STRONG AIRMASS BEHIND THE FRONT.

THE COLD FRONT IS EXPECTED TO ENTER THE NORTHWEST PORTION OF THE
FORECAST AREA BY 18Z ON WEDNESDAY...AND MOVE TO THE EAST OF THE AREA
BY 00Z THURSDAY. BEHIND THE FRONT...TEMPERATURES WILL DROP
QUICKLY...WITH MUCH OF THE AREA NEAR OR BELOW FREEZING BY 00Z. THE
UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA WILL PHASE WITH THE
UPPER TROUGH OVER CANADA AND THE UPPER LEVEL JET IS EXPECTED TO
INTENSIFY SIGNIFICANTLY. THE FORECAST AREA WILL BE LOCATED IN THE
AREA OF ENHANCED LIFT...WITH AN ABUNDANCE OF MOISTURE LAGGING BEHIND
THE FRONT AS WELL. THIS SETS THE STAGE FOR ONGOING MODERATE
PRECIPITATION ACROSS THE AREA. AS TEMPERATURES FALL DURING THE
AFTERNOON...RAIN WILL TRANSITION TO FREEZING RAIN ACROSS THE
NORTHWEST...AND THEN CONTINUE TO TRANSITION ACROSS THE REST OF THE
AREA. MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF FREEZING RAIN
ACROSS MUCH OF THE AREA...WITH A BRIEF CHANGE OVER TO SLEET BY
06Z...AND THEN TO LIGHT SNOW BY 12Z. FAIRLY SIGNIFICANT ICE
ACCUMULATIONS ARE POSSIBLE...WITH MUCH OF THE AREA EXPECTED TO
RECEIVE AROUND A QUARTER OF INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THE WARM NOSE ALOFT WILL COOL FASTER ACROSS THE
NORTHWEST...WHERE A TRANSITION TO SLEET AND SNOW WILL OCCUR SOONER.
THEREFORE...IN THESE LOCATIONS...UP TO 2 INCHES OF SNOW/SLEET
ACCUMULATIONS ARE POSSIBLE. IF THE TRENDS CONTINUE...THESE AMOUNTS
MAY HAVE TO BE ADJUSTED. AGAIN...IT SHOULD BE NOTED THAT EVEN WITH
THE SLOWER MODEL SOLUTIONS...THERE WILL STILL BE THE THREAT FOR
FROZEN PRECIPITATION BEHIND THE FRONT...HOWEVER THE DURATION MAY BE
LESS.

BEYOND 12Z THURSDAY...PRECIPITATION WILL COME TO AN END FROM WEST TO
EAST AS HIGH PRESSURE BUILDS IN. TEMPERATURES WILL NOT WARM UP VERY
MUCH ON THURSDAY...WITH MOST LOCATIONS REMAINING BELOW FREEZING.
TEMPS ON FRIDAY WILL BOTTOM OUT IN THE TEENS...BEFORE WARMING INTO
THE LOWER 40S. A LIGHT WARMING TREND WILL CONTINUE THROUGH THE
EXTENDED...WITH ONLY A SLIGHT CHANCE OF RAIN EXPECTED TOWARDS THE
LATTER PART OF THE PERIOD.

73

&&

.AVIATION...
FOR 12Z TAFS...COLD FRONT HAS PUSHED SOUTH OF BOTH HSV/MSL WITH NNE
FLOW OF 10G18 KTS EXPECTED TO PERSIST THROUGH 02/15Z...ALONG WITH
IFR CIGS AND MVFR VSBY REDUCTIONS IN -DZ/BR. WEAK MIXING IN WAKE OF
FRONT AND DRIER AIRMASS MOVING INTO THE REGION SHOULD ALLOW VSBY TO
IMPROVE AND CIGS TO LIFT INTO THE 1500-2500 FT RANGE BY 15Z...AS
WINDS DIMINISH AND VEER TO ENE. THREAT FOR SHRA MAY INCREASE ONCE
AGAIN BY 21Z AS A WEAK UPPER AIR DISTURBANCE APPROACHES...ALTHOUGH
GIVEN SCT COVERAGE EXPECT CIGS TO REMAIN MVFR UNTIL LOW-LEVEL FLOW
VEERS TO ESE ARND 03/03Z. WINDS WILL INCREASE AND SHIFT TO SSE BY 08Z
AS WARM FRONT MOVES NWD...WITH MVFR VSBY REDUCTIONS IN BR PSBL BEYOND
THIS POINT. THREAT FOR SCT SHRA WILL CONTINUE OVERNIGHT... WITH A FEW
STORMS ALSO PSBL. HOWEVER...THREAT FOR TSRA IS TOO LOW TO MENTION IN
TAF ATTM.

70/DD

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 021100
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
500 AM CST MON MAR 2 2015

.DISCUSSION...

WATER VAPOR IMAGERY SHOWS MUCH OF THE AREA UNDER ZONAL FLOW
ALOFT. AT THE SURFACE...LIGHT RAIN CONTINUES TO MOVE EAST ACROSS THE
FORECAST AREA...BEHIND A SURFACE COLD FRONT THAT HAS PUSHED TO THE
EAST OF THE AREA. THIS FRONT IS EXPECTED TO STALL TO THE SOUTH...WITH
SHOWERS CONTINUING THROUGH THE MORNING IN RESPONSE TO SEVERAL WEAK
SHORTWAVES MOVING EAST IN THE UPPER LEVEL ZONAL FLOW. COVERAGE WILL
LIKELY DECREASE THIS AFTERNOON...AS DRIER AIR FILTERS INTO THE
REGION. HIGH PRESSURE AT THE SURFACE WILL MOVE EAST ACROSS THE GREAT
LAKES...WITH NORTHERLY WINDS SHIFTING TO THE EAST THIS EVENING. THE
AFOREMENTIONED COLD FRONT IS EXPECTED TO LIFT NORTHWARD
OVERNIGHT...WITH SHOWERS...WITH AN ISOLATED THUNDERSTORM...POSSIBLE
AFTER 06Z. ALTHOUGH SHOWERS WILL LIKELY BE ONGOING TUESDAY
MORNING...TEMPERATURES ARE EXPECTED TO WARM UP QUITE A BIT...DUE TO
THE STRONG WAA AT THE SURFACE AND A DECREASE IN RAIN COVERAGE BY THE
AFTERNOON.

THE MAIN FOCUS FOR THE FORECAST THIS MORNING CONTINUES TO BE THE
SETUP ON TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AN UPPER LEVEL
CLOSED LOW OFF OF THE SOUTHERN CALIFORNIA COAST WILL PUSH ASHORE
LATER TODAY...AS AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTHWARD OUT
OF CANADA. SURFACE CYCLOGENESIS WILL OCCUR OVER CANADA...WITH A
DEEPENING SURFACE LOW EXPECTED TO MOVE EAST ACROSS THE GREAT LAKES. A
STRONG COLD FRONT WILL DEVELOP AND DRAG SOUTHWARD FROM THE SURFACE
LOW AND MOVE THROUGH THE FORECAST AREA WEDNESDAY INTO THURSDAY.
WHILE MODEL GUIDANCE IS STILL IN GOOD AGREEMENT WITH THE OVERALL
SETUP...THE TIMING DIFFERENCES ARE STILL GLARING...WITH EACH TIMING
SCENARIO POSING A DIFFERENT SET OF THREATS FOR THE FORECAST AREA.
THIS MAKES THINGS QUITE UNCERTAIN...HOWEVER FOR NOW...HAVE GONE WITH
A BLEND OF THE GFS AND ECMWF...WITH AN EMPHASIS ON THE GFS.

AHEAD OF THE COLD FRONT...A 50-60KT LLJ WILL MOVE JUST TO THE NORTH
OF THE FORECAST AREA. SOUTHERLY FLOW AT THE SURFACE CONTINUES...WITH
HIGHS ON TUESDAY IN THE UPPER 60S...AND DEWPOINTS REACHING INTO THE
UPPER 50S. SHOWERS...WITH ISOLATED THUNDERSTORMS ARE POSSIBLE
OVERNIGHT TUESDAY AND INTO EARLY WEDNESDAY MORNING. INSTABILITY DOES
APPEAR TO BE LIMITED...GIVEN A FAIRLY STRONG CAPPING INVERSION
ADVERTISED BY MODEL SOUNDINGS. WIND SHEAR WILL BE DECENT TO SUPPORT A
FEW ORGANIZED THUNDERSTORMS...BUT GIVEN THE CURRENT SOLUTION...THERE
LOOKS TO BE ONLY A SMALL WINDOW WHERE STRONG TO SEVERE THUNDERSTORMS
WILL BE POSSIBLE...JUST AHEAD OF THE COLD FRONT. IF THE SLOWER NAM
SOLUTION PANS OUT...WE MAY HAVE MORE TIME TO WARM UP ON WEDNESDAY
AFTERNOON AND THERE WOULD BE MORE OF AN OPPORTUNITY FOR THE INVERSION
TO DIMINISH. HOWEVER...THE NAM SEEMS TO BE A BIT TOO SLOW...GIVEN THE
STRONG AIRMASS BEHIND THE FRONT.

THE COLD FRONT IS EXPECTED TO ENTER THE NORTHWEST PORTION OF THE
FORECAST AREA BY 18Z ON WEDNESDAY...AND MOVE TO THE EAST OF THE AREA
BY 00Z THURSDAY. BEHIND THE FRONT...TEMPERATURES WILL DROP
QUICKLY...WITH MUCH OF THE AREA NEAR OR BELOW FREEZING BY 00Z. THE
UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA WILL PHASE WITH THE
UPPER TROUGH OVER CANADA AND THE UPPER LEVEL JET IS EXPECTED TO
INTENSIFY SIGNIFICANTLY. THE FORECAST AREA WILL BE LOCATED IN THE
AREA OF ENHANCED LIFT...WITH AN ABUNDANCE OF MOISTURE LAGGING BEHIND
THE FRONT AS WELL. THIS SETS THE STAGE FOR ONGOING MODERATE
PRECIPITATION ACROSS THE AREA. AS TEMPERATURES FALL DURING THE
AFTERNOON...RAIN WILL TRANSITION TO FREEZING RAIN ACROSS THE
NORTHWEST...AND THEN CONTINUE TO TRANSITION ACROSS THE REST OF THE
AREA. MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF FREEZING RAIN
ACROSS MUCH OF THE AREA...WITH A BRIEF CHANGE OVER TO SLEET BY
06Z...AND THEN TO LIGHT SNOW BY 12Z. FAIRLY SIGNIFICANT ICE
ACCUMULATIONS ARE POSSIBLE...WITH MUCH OF THE AREA EXPECTED TO
RECEIVE AROUND A QUARTER OF INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THE WARM NOSE ALOFT WILL COOL FASTER ACROSS THE
NORTHWEST...WHERE A TRANSITION TO SLEET AND SNOW WILL OCCUR SOONER.
THEREFORE...IN THESE LOCATIONS...UP TO 2 INCHES OF SNOW/SLEET
ACCUMULATIONS ARE POSSIBLE. IF THE TRENDS CONTINUE...THESE AMOUNTS
MAY HAVE TO BE ADJUSTED. AGAIN...IT SHOULD BE NOTED THAT EVEN WITH
THE SLOWER MODEL SOLUTIONS...THERE WILL STILL BE THE THREAT FOR
FROZEN PRECIPITATION BEHIND THE FRONT...HOWEVER THE DURATION MAY BE
LESS.

BEYOND 12Z THURSDAY...PRECIPITATION WILL COME TO AN END FROM WEST TO
EAST AS HIGH PRESSURE BUILDS IN. TEMPERATURES WILL NOT WARM UP VERY
MUCH ON THURSDAY...WITH MOST LOCATIONS REMAINING BELOW FREEZING.
TEMPS ON FRIDAY WILL BOTTOM OUT IN THE TEENS...BEFORE WARMING INTO
THE LOWER 40S. A LIGHT WARMING TREND WILL CONTINUE THROUGH THE
EXTENDED...WITH ONLY A SLIGHT CHANCE OF RAIN EXPECTED TOWARDS THE
LATTER PART OF THE PERIOD.

73

&&

.AVIATION...
/ISSUED 1048 PM CST SUN MAR 1 2015/
FOR 06Z TAFS... IFR CONDS ARE EXPECTED UNTIL MONDAY MORNING AS AREAS
OF -RA/DZ AND LOW CIGS PERSIST. A COLD FRONTAL PASSAGE WILL OCCUR AT
KMSL BY ~08Z AND KHSV BY ~10Z WITH A WIND SHIFT TO A NORTHERLY
DIRECTION. CONDS MAY IMPROVE TO MVFR ~14Z ON MONDAY MORNING AS RAIN
DIMINISHES OR ENDS AND CIGS LIFT INTO THE 020-030AGL RANGE. MVFR
CONDS ARE EXPECTED THRU THE REMAINDER OF THE PD.

AK

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    47  45  65  55 /  60  60  60  80
SHOALS        46  43  66  54 /  60  50  60  80
VINEMONT      44  42  65  55 /  70  60  60  80
FAYETTEVILLE  41  41  64  51 /  50  50  60  80
ALBERTVILLE   47  44  66  55 /  80  60  60  80
FORT PAYNE    46  43  60  55 /  70  60  70  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.





000
FXUS64 KHUN 021100
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
500 AM CST MON MAR 2 2015

.DISCUSSION...

WATER VAPOR IMAGERY SHOWS MUCH OF THE AREA UNDER ZONAL FLOW
ALOFT. AT THE SURFACE...LIGHT RAIN CONTINUES TO MOVE EAST ACROSS THE
FORECAST AREA...BEHIND A SURFACE COLD FRONT THAT HAS PUSHED TO THE
EAST OF THE AREA. THIS FRONT IS EXPECTED TO STALL TO THE SOUTH...WITH
SHOWERS CONTINUING THROUGH THE MORNING IN RESPONSE TO SEVERAL WEAK
SHORTWAVES MOVING EAST IN THE UPPER LEVEL ZONAL FLOW. COVERAGE WILL
LIKELY DECREASE THIS AFTERNOON...AS DRIER AIR FILTERS INTO THE
REGION. HIGH PRESSURE AT THE SURFACE WILL MOVE EAST ACROSS THE GREAT
LAKES...WITH NORTHERLY WINDS SHIFTING TO THE EAST THIS EVENING. THE
AFOREMENTIONED COLD FRONT IS EXPECTED TO LIFT NORTHWARD
OVERNIGHT...WITH SHOWERS...WITH AN ISOLATED THUNDERSTORM...POSSIBLE
AFTER 06Z. ALTHOUGH SHOWERS WILL LIKELY BE ONGOING TUESDAY
MORNING...TEMPERATURES ARE EXPECTED TO WARM UP QUITE A BIT...DUE TO
THE STRONG WAA AT THE SURFACE AND A DECREASE IN RAIN COVERAGE BY THE
AFTERNOON.

THE MAIN FOCUS FOR THE FORECAST THIS MORNING CONTINUES TO BE THE
SETUP ON TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AN UPPER LEVEL
CLOSED LOW OFF OF THE SOUTHERN CALIFORNIA COAST WILL PUSH ASHORE
LATER TODAY...AS AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTHWARD OUT
OF CANADA. SURFACE CYCLOGENESIS WILL OCCUR OVER CANADA...WITH A
DEEPENING SURFACE LOW EXPECTED TO MOVE EAST ACROSS THE GREAT LAKES. A
STRONG COLD FRONT WILL DEVELOP AND DRAG SOUTHWARD FROM THE SURFACE
LOW AND MOVE THROUGH THE FORECAST AREA WEDNESDAY INTO THURSDAY.
WHILE MODEL GUIDANCE IS STILL IN GOOD AGREEMENT WITH THE OVERALL
SETUP...THE TIMING DIFFERENCES ARE STILL GLARING...WITH EACH TIMING
SCENARIO POSING A DIFFERENT SET OF THREATS FOR THE FORECAST AREA.
THIS MAKES THINGS QUITE UNCERTAIN...HOWEVER FOR NOW...HAVE GONE WITH
A BLEND OF THE GFS AND ECMWF...WITH AN EMPHASIS ON THE GFS.

AHEAD OF THE COLD FRONT...A 50-60KT LLJ WILL MOVE JUST TO THE NORTH
OF THE FORECAST AREA. SOUTHERLY FLOW AT THE SURFACE CONTINUES...WITH
HIGHS ON TUESDAY IN THE UPPER 60S...AND DEWPOINTS REACHING INTO THE
UPPER 50S. SHOWERS...WITH ISOLATED THUNDERSTORMS ARE POSSIBLE
OVERNIGHT TUESDAY AND INTO EARLY WEDNESDAY MORNING. INSTABILITY DOES
APPEAR TO BE LIMITED...GIVEN A FAIRLY STRONG CAPPING INVERSION
ADVERTISED BY MODEL SOUNDINGS. WIND SHEAR WILL BE DECENT TO SUPPORT A
FEW ORGANIZED THUNDERSTORMS...BUT GIVEN THE CURRENT SOLUTION...THERE
LOOKS TO BE ONLY A SMALL WINDOW WHERE STRONG TO SEVERE THUNDERSTORMS
WILL BE POSSIBLE...JUST AHEAD OF THE COLD FRONT. IF THE SLOWER NAM
SOLUTION PANS OUT...WE MAY HAVE MORE TIME TO WARM UP ON WEDNESDAY
AFTERNOON AND THERE WOULD BE MORE OF AN OPPORTUNITY FOR THE INVERSION
TO DIMINISH. HOWEVER...THE NAM SEEMS TO BE A BIT TOO SLOW...GIVEN THE
STRONG AIRMASS BEHIND THE FRONT.

THE COLD FRONT IS EXPECTED TO ENTER THE NORTHWEST PORTION OF THE
FORECAST AREA BY 18Z ON WEDNESDAY...AND MOVE TO THE EAST OF THE AREA
BY 00Z THURSDAY. BEHIND THE FRONT...TEMPERATURES WILL DROP
QUICKLY...WITH MUCH OF THE AREA NEAR OR BELOW FREEZING BY 00Z. THE
UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA WILL PHASE WITH THE
UPPER TROUGH OVER CANADA AND THE UPPER LEVEL JET IS EXPECTED TO
INTENSIFY SIGNIFICANTLY. THE FORECAST AREA WILL BE LOCATED IN THE
AREA OF ENHANCED LIFT...WITH AN ABUNDANCE OF MOISTURE LAGGING BEHIND
THE FRONT AS WELL. THIS SETS THE STAGE FOR ONGOING MODERATE
PRECIPITATION ACROSS THE AREA. AS TEMPERATURES FALL DURING THE
AFTERNOON...RAIN WILL TRANSITION TO FREEZING RAIN ACROSS THE
NORTHWEST...AND THEN CONTINUE TO TRANSITION ACROSS THE REST OF THE
AREA. MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF FREEZING RAIN
ACROSS MUCH OF THE AREA...WITH A BRIEF CHANGE OVER TO SLEET BY
06Z...AND THEN TO LIGHT SNOW BY 12Z. FAIRLY SIGNIFICANT ICE
ACCUMULATIONS ARE POSSIBLE...WITH MUCH OF THE AREA EXPECTED TO
RECEIVE AROUND A QUARTER OF INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THE WARM NOSE ALOFT WILL COOL FASTER ACROSS THE
NORTHWEST...WHERE A TRANSITION TO SLEET AND SNOW WILL OCCUR SOONER.
THEREFORE...IN THESE LOCATIONS...UP TO 2 INCHES OF SNOW/SLEET
ACCUMULATIONS ARE POSSIBLE. IF THE TRENDS CONTINUE...THESE AMOUNTS
MAY HAVE TO BE ADJUSTED. AGAIN...IT SHOULD BE NOTED THAT EVEN WITH
THE SLOWER MODEL SOLUTIONS...THERE WILL STILL BE THE THREAT FOR
FROZEN PRECIPITATION BEHIND THE FRONT...HOWEVER THE DURATION MAY BE
LESS.

BEYOND 12Z THURSDAY...PRECIPITATION WILL COME TO AN END FROM WEST TO
EAST AS HIGH PRESSURE BUILDS IN. TEMPERATURES WILL NOT WARM UP VERY
MUCH ON THURSDAY...WITH MOST LOCATIONS REMAINING BELOW FREEZING.
TEMPS ON FRIDAY WILL BOTTOM OUT IN THE TEENS...BEFORE WARMING INTO
THE LOWER 40S. A LIGHT WARMING TREND WILL CONTINUE THROUGH THE
EXTENDED...WITH ONLY A SLIGHT CHANCE OF RAIN EXPECTED TOWARDS THE
LATTER PART OF THE PERIOD.

73

&&

.AVIATION...
/ISSUED 1048 PM CST SUN MAR 1 2015/
FOR 06Z TAFS... IFR CONDS ARE EXPECTED UNTIL MONDAY MORNING AS AREAS
OF -RA/DZ AND LOW CIGS PERSIST. A COLD FRONTAL PASSAGE WILL OCCUR AT
KMSL BY ~08Z AND KHSV BY ~10Z WITH A WIND SHIFT TO A NORTHERLY
DIRECTION. CONDS MAY IMPROVE TO MVFR ~14Z ON MONDAY MORNING AS RAIN
DIMINISHES OR ENDS AND CIGS LIFT INTO THE 020-030AGL RANGE. MVFR
CONDS ARE EXPECTED THRU THE REMAINDER OF THE PD.

AK

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    47  45  65  55 /  60  60  60  80
SHOALS        46  43  66  54 /  60  50  60  80
VINEMONT      44  42  65  55 /  70  60  60  80
FAYETTEVILLE  41  41  64  51 /  50  50  60  80
ALBERTVILLE   47  44  66  55 /  80  60  60  80
FORT PAYNE    46  43  60  55 /  70  60  70  80

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.




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