000
FXUS61 KRNK 181522
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1122 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A FRONT EXTENDED FROM CENTRAL OHIO INTO NORTHEAST NORTH CAROLINA
THIS MORNING. THIS FRONT WILL DRIFT SOUTHEAST AND REMAIN ACROSS
THE MID ATLANTIC REGION THROUGH SUNDAY NIGHT. BY TUESDAY LOW
PRESSURE OVER THE MISSISSIPPI VALLEY WILL PUSH THE FRONT NORTH
OUT OF THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM EDT SATURDAY...
WEAK HIGH PRESSURE REMAINS WEDGED AGAINST THE EASTERN FACE OF THE
APPALACHIANS THIS MORNING...WHILE AN UPPER LEVEL TROUGH APPROACHES
FROM THE WEST. ONE DISTURBANCE ROTATING AROUND THE BASE OF THE
TROUGH HAS TRIGGERED WIDESPREAD SHOWER ACTIVITY ACROSS THE
MOUNTAINS AND FOOTHILLS OF NORTH CAROLINA INTO THE MOUNTAIN
EMPIRE...AND EXPECT THIS ACTIVITY TO SPREAD ACROSS THE MOUNTAINS
THROUGH THE AFTERNOON. WILL BE MONITORING THIS ROUND OF RAIN FOR
ANY POTENTIAL FOR INTENSIFICATION OR TRAINING...BUT SO FAR THERE
HAVE BEEN NO PROBLEMS REPORTED. CLOUD COVER HAS REMAINED
WIDESPREAD THROUGH THE MORNING...WHICH HAS KEPT A LID ON
INSTABILITY...BUT WILL STILL BE LOOKING FOR AN INCREASE OF SHOWER
ACTIVITY BY EARLY AFTERNOON AS DAYTIME HEATING INCREASES.
STILL MAINTAINING EARLIER CONCERNS FOR THE POSSIBILITY OF HEAVY
RAIN...AND POTENTIAL FLOODING FOR TONIGHT THROUGH THE BEGINNING OF
THE WORKWEEK...AS ROUNDS OF RAINFALL ASSOCIATED WITH THE
APPROACHING UPPER LEVEL TROUGH PASS ACROSS THE AREA. CURRENTLY
OBSERVING A STALLED FRONT SITUATED ACROSS CENTRAL VIRGINIA. SURFACE
WINDS REMAIN FROM THE EAST...BUT WINDS A FEW THOUSAND FEET OFF THE
SURFACE ARE OUT OF THE SOUTH. THIS FRONT WILL SERVE AS LOW LEVEL
SUPPORT FOR RAINFALL AS UNSTABLE AND VERY MOIST AIR LIFTING OVER
THIS BOUNDARY WILL TRANSFORM INTO SHOWERS AND THUNDERSTORMS IN
THE EAST THROUGH SUNDAY MORNING.
PRECIPITABLE WATER VALUES IN THE EASTERN FORECAST AREA WILL REACH
AROUND 1.75 INCHES WHICH IS 2 STANDARD DEVIATIONS...WELL ABOVE
NORMAL. PRECIPITATION POTENTIAL PLACEMENT ON BOTH THE NAM AND GFS
REMAINS EXCEPTIONALLY HIGH BETWEEN 00Z/8PM TONIGHT AND 12Z/8AM
SUNDAY. ALREADY HAVE A FLASH FLOOD WATCH IN THE NORTH CAROLINA
MOUNTAINS INTO THE MOUNTAIN EMPIRE...AND AM STILL DEBATING THE
NEED AND THE LOCATION FOR A FLOOD WATCH FURTHER TO THE EAST.
CLOUDS WILL LIMIT WARM UP TODAY IN ALL BUT THE FAR SOUTHEAST PART
OF THE FORECAST AREA...WHERE VISIBLE SATELLITE IMAGERY INDICATES
THINNING IN THE CLOUD COVER. USE BIAS CORRECTED MET GUIDANCE AND
LATEST GRIDDED LAMP GUIDANCE FOR HIGHS TODAY. DEW POINTS INTO THE
LOWER 60S WILL KEEP MINIMUM TEMPERATURES MILD TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 319 AM EDT SATURDAY...
SHORTWAVE THAT CAUSED SO MUCH TROUBLE ACROSS TEXAS ARRIVES IN A
WEAKENED FORM ON SUNDAY...SLOWLY MOVING ACROSS THE REGION.
CONSIDERING THE RAIN THAT FELL OVER THE PAST 24 HOURS...AND
ADDITIONAL RAINFALL ON SATURDAY...A FLASH FLOOD WATCH MAY BE NEEDED
FOR THE VIRGINIA PIEDMONT AND ALSO NW NC FOR SUNDAY. MODELS ARE
SIMILAR TO YESTERDAY`S RUNS WHICH ELEVATED PWATS ABOVE 1.5" ACROSS
THE VIRGINIA PIEDMONT. PATTERN RECOGNITION WOULD SUGGEST AT LEAST
SOME WATER PROBLEMS DEVELOP...AS UPSLOPE FLOW...NEARBY BACKDOOR
BOUNDARY AND ARRIVING SHORTWAVE HAVE LED TO ISSUES IN THE PAST.
WEAK MBE VELOCITIES SUGGEST SLOW MOVERS AND/OR BACKBUILDERS. WITH
THE WAVE MOVING EAST WITH SOME SINKING MOTION/SOME DRIER AIR AT
H7...EXPECTING LESS COVERAGE ON MONDAY...BUT THERE WILL REMAIN THE
CHANCE FOR ELEVATED CONVECTION ALONG THE BLUE RIDGE DURING PEAK
HEATING. HIGHEST POPS WILL BE ALONG AND EAST OF THE BLUE RIDGE
MONDAY. RELATIVE POP MINIMUM FOR EXTREME WESTERN VA AND SE WEST
VA. TUESDAY LOOKS TO BE THE WARMEST AND DRIEST DAY OF THE SHORT
TERM FORECAST WITH H5 HEIGHTS RISING THANKS TO A DIGGING MIDWEST
TROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 AM EDT SATURDAY...
PATCHES OF IFR FOG AND IFR CEILINGS...MAINLY EAST OF THE BLUE
RIDGE WILL DISSIPATE BY MID MORNING.
A SHORT WAVE CROSSING SLOWLY OVER THE SOUTHERN APPALACHIANS TODAY
WILL TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EVENING. HIGH CONFIDENCE THIS WILL PRODUCE MVFR CEILINGS AND
VISIBILITIES ALONG WITH HEAVY RAIN. LITTLE CHANGE IN THE WEATHER
PATTERN IS EXPECTED ON SUNDAY. MORE SHOWERS AND THUNDERSTORMS
ALONG WITH MVFR TO IFR FLYING CONDITIONS WILL CONTINUE.
CONDITIONS LOOK TO IMPROVE MONDAY AS THE UPPER TROUGH MOVES
TO THE MID ATLANTIC COAST. EXPECT TUESDAY TO BE THE BEST BET FOR
DECENT FLYING CONDITIONS ALTHOUGH AN ISOLATED AFTERNOON AIRMASS
SHOWER OR THUNDERSTORM IS STILL POSSIBLE. NEXT FRONT APPROACHES
ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS FRONT DOES
NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVFR
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE LATTER
HALF OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR VAZ009-015.
NC...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR NCZ001-002-018.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/NF
SHORT TERM...KM
LONG TERM...DS
AVIATION...AMS/PM
000
FXUS61 KRNK 181149
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
749 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A FRONT EXTENDED FROM CENTRAL OHIO INTO NORTHEAST NORTH CAROLINA
THIS MORNING. THIS FRONT WILL DRIFT SOUTHEAST AND REMAIN ACROSS
THE MID ATLANTIC REGION THROUGH SUNDAY NIGHT. BY TUESDAY LOW
PRESSURE OVER THE MISSISSIPPI VALLEY WILL PUSH THE FRONT NORTH
OUT OF THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT SATURDAY...
SEVERAL FACTORS INDICATE AN INCREASED RISK OF FLOODING TODAY AND
TONIGHT. FLASH FLOOD GUIDANCE EAST OF THE BLUE RIDGE IS STILL
ABOVE 2.00 INCHES PER 3 HOURS. HOWEVER...SOME LOCATIONS FROM
CENTRAL PITTSYLVANIA COUNTY INTO EASTERN APPOMATTOX AND SOUTHERN
BUCKINGHAM COUNTY HAD MORE 1.5 TO 2.5 INCHES OF RAIN ON FRIDAY AND
FRIDAY NIGHT. IN THE MOUNTAINS FLASH FLOOD GUIDANCE RANGES FROM
1.5 TO 2.5 INCHES IN THREE HOURS.
SCATTERED SHOWERS REMAINED OVER AMHERST...APPOMATTOX AND
BUCKINGHAM COUNTIES EARLY THIS MORNING. ASIDE FROM THIS AREA AND A
ISOLATED SHOWERS IN SUMMERS AND GREENBRIER COUNTY WEST
VIRGINIA...MUCH OF THE FORECAST AREA WILL HAVE A BREAK IN THE RAIN
THIS MORNING.
A SURFACE FRONT WAS OVER THE EASTERN COUNTY WARNING AREA. BOUNDARY
SHOWED UP BEST IN THE LIFTED INDEX AND DEW POINT ANALYSIS.SURFACE
WINDS ARE OUT OF THE EAST...BUT JUST ABOVE THE SURFACE WINDS ARE
OUT OF THE SOUTH. UNSTABLE AND VERY MOIST AIR LIFTING OVER THIS
BOUNDARY WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS IN
THE EASTERN COUNTY WARNING AREA THROUGH SUNDAY MORNING.
A SHORT WAVE OVER CENTRAL TENNESSEE WILL MOVE SLOWLY EAST TODAY.
SHOWERS AND THUNDERSTORMS WILL FILL IN OVER THE CENTRAL
APPALACHIANS IN RESPONSE TO THIS FEATURE BY THIS AFTERNOON AND
WILL CONTINUE FOR MUCH OF TONIGHT.
PLUS SATELLITE PICTURES SHOWED A BREAK IN THE CLOUD COVER OVER
CENTRAL AND EASTERN NORTH CAROLINA. EXPECT THE SOUTHERN COUNTY
WARNING AREA TO GET SOME SUN THIS MORNING. THIS WILL INCREASE THE
INSTABILITY BY THE TIME SHOWERS AN THUNDERSTORMS FORM THIS
AFTERNOON.
PRECIPITABLE WATER VALUES IN THE EASTERN FORECAST AREA WILL REACH
AROUND 1.75 INCHES WHICH IS 2 STANDARD DEVIATIONS...WELL
ABOVE...NORMAL. PRECIPITATION POTENTIAL PLACEMENT ON BOTH THE NAM
AND GFS IS EXCEPTIONALLY HIGH BETWEEN 00Z/8PM TONIGHT AND 12Z/8AM
SUNDAY. SO IN MOUNTAINS AREAS THAT HAD HIGHER RAINFALL AMOUNTS ON
FRIDAY HAVE ISSUED A FLASH FLOOD WATCH.
CLOUDS WILL LIMIT WARM UP TODAY IN ALL BUT THE FAR SOUTHEAST PART
OF THE FORECAST AREA. USE BIAS CORRECTED MET GUIDANCE AND LATEST
GRIDDED LAMP GUIDANCE FOR HIGHS TODAY. DEW POINTS INTO THE LOWER
60S WILL KEEP MINIMUM TEMPERATURES MILD TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 319 AM EDT SATURDAY...
SHRTWV THAT CAUSED SO MUCH TROUBLE ACROSS TEXAS ARRIVES IN A
WEAKENED FORM ON SUNDAY...SLOWLY MOVING ACROSS THE REGION.
CONSIDERING THE RAIN THAT FELL OVER THE PAST 24 HOURS...AND
ADDITIONAL RAINFALL ON SATURDAY...A FLASH FLOOD WATCH MAY BE NEEDED
FOR THE VIRGINIA PIEDMONT AND ALSO NW NC FOR SUNDAY. MODELS ARE
SIMILAR TO YESTERDAY`S RUNS WHICH ELEVATED PWATS ABOVE 1.5" ACROSS
THE VIRGINIA PIEDMONT. PATTERN RECOGNITION WOULD SUGGEST AT LEAST
SOME WATER PROBLEMS DEVELOP...AS UPSLOPE FLOW...NEARBY BACKDOOR
BOUNDARY AND ARRIVING SHRTWV HAVE LED TO ISSUES IN THE PAST. WEAK
MBE VELOCITIES SUGGEST SLOW MOVERS AND/OR BACKBUILDERS. WITH THE
WAVE MOVING EAST WITH SOME SINKING MOTION/SOME DRIER AIR AT
H7...EXPECTING LESS COVERAGE ON MONDAY...BUT THERE WILL REMAIN THE
CHANCE FOR ELEVATED CONVECTION ALONG THE BLUE RIDGE DURING PEAK
HEATING. HIGHEST POPS WILL BE ALONG AND EAST OF THE BLUE RIDGE
MONDAY. RELATIVE POP MINIMUM FOR EXTREME WESTERN VA AND SE WEST VA.
TUESDAY LOOKS TO BE THE WARMEST AND DRIEST DAY OF THE SHORT TERM
FORECAST WITH H5 HEIGHTS RISING THANKS TO A DIGGING MIDWEST TROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 AM EDT SATURDAY...
PATCHES OF IFR FOG AND IFR CEILINGS...MAINLY EAST OF THE BLUE
RIDGE WILL DISSIPATE BY MID MORNING.
A SHORT WAVE CROSSING SLOWLY OVER THE SOUTHERN APPALACHIANS TODAY
WILL TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EVENING. HIGH CONFIDENCE THIS WILL PRODUCE MVFR CEILINGS AND
VISIBILITIES ALONG WITH HEAVY RAIN. LITTLE CHANGE IN THE WEATHER
PATTERN IS EXPECTED ON SUNDAY. MORE SHOWERS AND THUNDERSTORMS
ALONG WITH MVFR TO IFR FLYING CONDITIONS WILL CONTINUE.
CONDITIONS LOOK TO IMPROVE MONDAY AS THE UPPER TROUGH MOVES
TO THE MID ATLANTIC COAST. EXPECT TUESDAY TO BE THE BEST BET FOR
DECENT FLYING CONDITIONS ALTHOUGH AN ISOLATED AFTERNOON AIRMASS
SHOWER OR THUNDERSTORM IS STILL POSSIBLE. NEXT FRONT APPROACHES
ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS FRONT DOES
NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVFR
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE LATTER
HALF OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING
FOR VAZ009-015.
NC...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING
FOR NCZ001-002-018.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KM
LONG TERM...DS
AVIATION...AMS/PM
000
FXUS61 KRNK 180927
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
527 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A FRONT EXTENDED FROM CENTRAL OHIO INTO NORTHEAST NORTH CAROLINA
THIS MORNING. THIS FRONT WILL DRIFT SOUTHEAST AND REMAIN ACROSS
THE MID ATLANTIC REGION THROUGH SUNDAY NIGHT. BY TUESDAY LOW
PRESSURE OVER THE MISSISSIPPI VALLEY WILL PUSH THE FRONT NORTH
OUT OF THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT SATURDAY...
SEVERAL FACTORS INDICATE AN INCREASED RISK OF FLOODING TODAY AND
TONIGHT. FLASH FLOOD GUIDANCE EAST OF THE BLUE RIDGE IS STILL
ABOVE 2.00 INCHES PER 3 HOURS. HOWEVER...SOME LOCATIONS FROM
CENTRAL PITTSYLVANIA COUNTY INTO EASTERN APPOMATTOX AND SOUTHERN
BUCKINGHAM COUNTY HAD MORE 1.5 TO 2.5 INCHES OF RAIN ON FRIDAY AND
FRIDAY NIGHT. IN THE MOUNTAINS FLASH FLOOD GUIDANCE RANGES FROM
1.5 TO 2.5 INCHES IN THREE HOURS.
SCATTERED SHOWERS REMAINED OVER AMHERST...APPOMATTOX AND
BUCKINGHAM COUNTIES EARLY THIS MORNING. ASIDE FROM THIS AREA AND A
ISOLATED SHOWERS IN SUMMERS AND GREENBRIER COUNTY WEST
VIRGINIA...MUCH OF THE FORECAST AREA WILL HAVE A BREAK IN THE RAIN
THIS MORNING.
A SURFACE FRONT WAS OVER THE EASTERN COUNTY WARNING AREA. BOUNDARY
SHOWED UP BEST IN THE LIFTED INDEX AND DEW POINT ANALYSIS.SURFACE
WINDS ARE OUT OF THE EAST...BUT JUST ABOVE THE SURFACE WINDS ARE
OUT OF THE SOUTH. UNSTABLE AND VERY MOIST AIR LIFTING OVER THIS
BOUNDARY WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS IN
THE EASTERN COUNTY WARNING AREA THROUGH SUNDAY MORNING.
A SHORT WAVE OVER CENTRAL TENNESSEE WILL MOVE SLOWLY EAST TODAY.
SHOWERS AND THUNDERSTORMS WILL FILL IN OVER THE CENTRAL
APPALACHIANS IN RESPONSE TO THIS FEATURE BY THIS AFTERNOON AND
WILL CONTINUE FOR MUCH OF TONIGHT.
PLUS SATELLITE PICTURES SHOWED A BREAK IN THE CLOUD COVER OVER
CENTRAL AND EASTERN NORTH CAROLINA. EXPECT THE SOUTHERN COUNTY
WARNING AREA TO GET SOME SUN THIS MORNING. THIS WILL INCREASE THE
INSTABILITY BY THE TIME SHOWERS AN THUNDERSTORMS FORM THIS
AFTERNOON.
PRECIPITABLE WATER VALUES IN THE EASTERN FORECAST AREA WILL REACH
AROUND 1.75 INCHES WHICH IS 2 STANDARD DEVIATIONS...WELL
ABOVE...NORMAL. PRECIPITATION POTENTIAL PLACEMENT ON BOTH THE NAM
AND GFS IS EXCEPTIONALLY HIGH BETWEEN 00Z/8PM TONIGHT AND 12Z/8AM
SUNDAY. SO IN MOUNTAINS AREAS THAT HAD HIGHER RAINFALL AMOUNTS ON
FRIDAY HAVE ISSUED A FLASH FLOOD WATCH.
CLOUDS WILL LIMIT WARM UP TODAY IN ALL BUT THE FAR SOUTHEAST PART
OF THE FORECAST AREA. USE BIAS CORRECTED MET GUIDANCE AND LATEST
GRIDDED LAMP GUIDANCE FOR HIGHS TODAY. DEW POINTS INTO THE LOWER
60S WILL KEEP MINIMUM TEMPERATURES MILD TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 319 AM EDT SATURDAY...
SHRTWV THAT CAUSED SO MUCH TROUBLE ACROSS TEXAS ARRIVES IN A
WEAKENED FORM ON SUNDAY...SLOWLY MOVING ACROSS THE REGION.
CONSIDERING THE RAIN THAT FELL OVER THE PAST 24 HOURS...AND
ADDITIONAL RAINFALL ON SATURDAY...A FLASH FLOOD WATCH MAY BE NEEDED
FOR THE VIRGINIA PIEDMONT AND ALSO NW NC FOR SUNDAY. MODELS ARE
SIMILAR TO YESTERDAY`S RUNS WHICH ELEVATED PWATS ABOVE 1.5" ACROSS
THE VIRGINIA PIEDMONT. PATTERN RECOGNITION WOULD SUGGEST AT LEAST
SOME WATER PROBLEMS DEVELOP...AS UPSLOPE FLOW...NEARBY BACKDOOR
BOUNDARY AND ARRIVING SHRTWV HAVE LED TO ISSUES IN THE PAST. WEAK
MBE VELOCITIES SUGGEST SLOW MOVERS AND/OR BACKBUILDERS. WITH THE
WAVE MOVING EAST WITH SOME SINKING MOTION/SOME DRIER AIR AT
H7...EXPECTING LESS COVERAGE ON MONDAY...BUT THERE WILL REMAIN THE
CHANCE FOR ELEVATED CONVECTION ALONG THE BLUE RIDGE DURING PEAK
HEATING. HIGHEST POPS WILL BE ALONG AND EAST OF THE BLUE RIDGE
MONDAY. RELATIVE POP MINIMUM FOR EXTREME WESTERN VA AND SE WEST VA.
TUESDAY LOOKS TO BE THE WARMEST AND DRIEST DAY OF THE SHORT TERM
FORECAST WITH H5 HEIGHTS RISING THANKS TO A DIGGING MIDWEST TROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 200 AM EDT SATURDAY...
A CLUSTER OF SHOWERS AND THUNDERSTORMS WAS MOVING NORTHEAST AND
AWAY FROM SOUTHWEST VIRGINIA EARLY THIS MORNING. A FEW LIGHT
SHOWERS ARE STILL POSSIBLE AT BCB AND ROA THROUGH 12Z. WEAK EAST
SURFACE WINDS MAY LEAD TO LOW CLOUDS AND IFR CEILINGS DEVELOPING
ALONG THE EAST SLOPE OF THE BLUE RIDGE THIS MORNING. CONFIDENCE IS
LOW SO FOR NOW HAVE FORECAST MVFR CEILINGS AT ALL TAF SITES. IN
ADDITION...RAIN FROM FRIDAY ALONG WITH LIGHT WINDS AND SURFACE DEW
POINTS IN THE 60S WILL RESULT IN FOG OVERNIGHT. MOST LIKELY TAF
SITES WHERE LIFR FOG MAY DEVELOP BEFORE 12Z WERE BCB...LWB AND
BLF.
A SHORT WAVE CROSSING SLOWLY OVER THE SOUTHERN APPALACHIANS TODAY
WILL TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS MAINLY THIS
AFTERNOON AND EVENING. THIS WILL PRODUCE MVFR CEILINGS AND
VISIBILITIES ALONG WITH HEAVY RAIN. LITTLE CHANGE IN THE WEATHER
PATTERN IS EXPECTED ON SUNDAY. MORE SHOWERS AND THUNDERSTORMS
ALONG WITH MVFR TO IFR FLYING CONDITIONS WILL CONTINUE.
CONDITIONS LOOK TO IMPROVE MONDAY AS THE UPPER TROUGH MOVES
TO THE MID ATLANTIC COAST. EXPECT TUESDAY TO BE THE BEST BET FOR
DECENT FLYING CONDITIONS ALTHOUGH AN ISOLATED AFTERNOON AIRMASS
SHOWER OR THUNDERSTORM IS STILL POSSIBLE. NEXT FRONT APPROACHES
ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS FRONT DOES
NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVFR
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE LATTER
HALF OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING
FOR VAZ009-015.
NC...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING
FOR NCZ001-002-018.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KM
LONG TERM...DS
AVIATION...AMS/PM
000
FXUS61 KRNK 180606
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
206 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE SOUTH TONIGHT ACROSS THE
EASTERN HALF OF THE FORECAST REGION...ALLOWING WEAK HIGH PRESSURE
TO WEDGE AGAINST THE MOUNTAINS. AN UPPER LEVEL DISTURBANCE WILL
ADVANCE TOWARD THE CENTRAL APPALACHIAN CHAIN ON SATURDAY...
INCREASING THE CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE
AREA. A DEEP UPPER LEVEL LOW PRESSURE SYSTEM WILL APPROACH THE
AREA TOWARD THE END OF THE COMING WEEK...WHICH MAY BRING A RETURN
OF COOLER WEATHER.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT FRIDAY...
SCATTERED SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE ACROSS THE
FORECAST AREA. SURFACE FRONT IS GRADUALLY BACKDOORING IN FROM THE
NORTHEAST...BOUNDARY LAYER WINDS GRADUALLY SHIFTING AROUND AND
COMING FROM AN EASTERLY DIRECTION. ALOFT HOWEVER...WINDS IN BOTH
THE GSO/RNK SOUNDINGS WERE FROM THE SOUTH. WITH THIS WARM MOIST
AIR RIDING UP AND OVER THE FRONT...EXPECT SHOWER THREAT TO
CONTINUE THROUGH THE OVERNIGHT. CAN`T RULE OUT A RUMBLE OF THUNDER
AS THERE IS SOME ELEVATED CAPE...BOTH THE GSO/RNK SOUNDINGS
SHOWING CAPE OF ABOUT 1000-1500 J/KG. WINDS ALOFT ARE RELATIVELY
WEAK...MEAN WIND OF ABOUT 10KTS/12MPH. AS SUCH STORM MOVEMENT IS
SLOW...THUS RESULTING IN PERSISTENCE OF HEAVY RAIN WHERE IT
HAPPENS TO OCCUR...SOME CASES RESULTING IN AN INCH OF RAIN IN LESS
THAN AN HOUR.
THROUGH THE OVERNIGHT...WILL SEE GREATEST CONCENTRATION OF
SHOWERS AND A FEW THUNDERSTORMS OVER THE PIEDMONT AS THE FRONT
ENTERS THE AREA AND WIND SPEEDS ALOFT DIMINISH. EXPECT THAT THE
ACTIVITY WILL REMAIN PULSY IN NATURE...ALTHOUGH WOULD NOT BE
SURPRISED TO SEE CLUSTERS OF SEMI-ORGANIZED CELLS WHERE OUTFLOW
BOUNDARIES MERGE. RAINFALL SHOULD DECREASE IN COVERAGE HEADING
INTO THE EARLY HOURS OF SATURDAY...THEN INCREASE AGAIN BY SATURDAY
AFTERNOON.
SHOWER AND THUNDERSTORM ACTIVITY WILL BECOME MORE WIDESPREAD
GOING INTO SATURDAY AFTERNOON AS THE UPPER LEVEL TROUGH MOVES
CLOSER. INCREASED CLOUD COVER AND SCATTERED RAINFALL WILL LIMIT
SURFACED BASED INSTABILITY...WITH AFTERNOON HIGHS HOLDING MAINLY
IN THE UPPER 60S TO MID 70S...SO DO NOT FORESEE A LARGE THREAT OF
SEVERE THUNDERSTORM ACTIVITY DURING THE AFTERNOON. HOWEVER...WEAK
UPPER LEVEL WINDS WILL RESULT IN SLOW MOVEMENT OF ANY STRONGER
SHOWERS AND STORMS...WHICH MAY LEAD TO LOCALLY HEAVY RAIN. BELIEVE
WE WILL HAVE A FEW AREAS OF LOCALIZED NUISANCE FLOODING WHERE
HEAVY RAIN DEVELOPS...BUT DO NOT FORESEE THE THREAT TO BE
WIDESPREAD ENOUGH AT THIS TIME TO GO WITH ANY SORT OF FLOOD WATCH.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 330 PM EDT FRIDAY...
SLOW MOVING UPPER LOW/TROUGH WILL MAKE ITS WAY EASTWARD ALONG A
STALLED FRONTAL BOUNDARY. ITS PASSAGE WILL ALLOW FOR DAILY ORGANIZED
SHOWERS AND STORMS TO OCCUR ACROSS THE AREA. SOME WILL BE DRIVEN BY
THE DYNAMICS OF THE SYSTEM...THOSE OCCURRING DURING THE DAY WILL
BENEFIT FROM DAYTIME INSTABILITY AS WELL. THE AXIS OF THE SYSTEM IS
PROGGED TO LIFT NORTHEAST OF THE AREA LATE IN THE DAY MONDAY. WE
EXPECTED A GRADUAL DECREASE IN COVERAGE DURING THIS TIME
PERIOD...WITH THE GREATEST COVERAGE ACROSS THE EASTERN PART OF THE
FORECAST AREA.
TEMPERATURES WILL AVERAGE NEAR NORMAL...IF NOT A SLIGHTLY ABOVE
NORMAL ON AVERAGE GIVEN ELEVATED DEW POINT VALUES OVERNIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 200 AM EDT SATURDAY...
A CLUSTER OF SHOWERS AND THUNDERSTORMS WAS MOVING NORTHEAST AND
AWAY FROM SOUTHWEST VIRGINIA EARLY THIS MORNING. A FEW LIGHT
SHOWERS ARE STILL POSSIBLE AT BCB AND ROA THROUGH 12Z. WEAK EAST
SURFACE WINDS MAY LEAD TO LOW CLOUDS AND IFR CEILINGS DEVELOPING
ALONG THE EAST SLOPE OF THE BLUE RIDGE THIS MORNING. CONFIDENCE IS
LOW SO FOR NOW HAVE FORECAST MVFR CEILINGS AT ALL TAF SITES. IN
ADDITION...RAIN FROM FRIDAY ALONG WITH LIGHT WINDS AND SURFACE DEW
POINTS IN THE 60S WILL RESULT IN FOG OVERNIGHT. MOST LIKELY TAF
SITES WHERE LIFR FOG MAY DEVELOP BEFORE 12Z WERE BCB...LWB AND
BLF.
A SHORT WAVE CROSSING SLOWLY OVER THE SOUTHERN APPALACHIANS TODAY
WILL TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS MAINLY THIS
AFTERNOON AND EVENING. THIS WILL PRODUCE MVFR CEILINGS AND
VISIBILITIES ALONG WITH HEAVY RAIN. LITTLE CHANGE IN THE WEATHER
PATTERN IS EXPECTED ON SUNDAY. MORE SHOWERS AND THUNDERSTORMS
ALONG WITH MVFR TO IFR FLYING CONDITIONS WILL CONTINUE.
CONDITIONS LOOK TO IMPROVE MONDAY AS THE UPPER TROUGH MOVES
TO THE MID ATLANTIC COAST. EXPECT TUESDAY TO BE THE BEST BET FOR
DECENT FLYING CONDITIONS ALTHOUGH AN ISOLATED AFTERNOON AIRMASS
SHOWER OR THUNDERSTORM IS STILL POSSIBLE. NEXT FRONT APPROACHES
ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS FRONT DOES
NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVFR
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE LATTER
HALF OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF/PM
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/PM
000
FXUS61 KRNK 180301
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1101 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE SOUTH THIS EVENING AND
TONIGHT ACROSS THE EASTERN HALF OF THE FORECAST REGION...ALLOWING
WEAK HIGH PRESSURE TO WEDGE AGAINST THE MOUNTAINS. AN UPPER LEVEL
DISTURBANCE WILL ADVANCE TOWARD THE CENTRAL APPALACHIAN CHAIN ON
SATURDAY...INCREASING THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA. A DEEP UPPER LEVEL LOW PRESSURE SYSTEM WILL
APPROACH THE AREA TOWARD THE END OF THE COMING WEEK...WHICH MAY
BRING A RETURN OF COOLER WEATHER.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1030 PM EDT FRIDAY...
SCATTERED SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE ACROSS THE
FORECAST AREA. SURFACE FRONT IS GRADUALLY BACKDOORING IN FROM THE
NORTHEAST...BOUNDARY LAYER WINDS GRADUALLY SHIFTING AROUND AND
COMING FROM AN EASTERLY DIRECTION. ALOFT HOWEVER...WINDS IN BOTH
THE GSO/RNK SOUNDINGS WERE FROM THE SOUTH. WITH THIS WARM MOIST
AIR RIDING UP AND OVER THE FRONT...EXPECT SHOWER THREAT TO
CONTINUE THROUGH THE OVERNIGHT. CAN`T RULE OUT A RUMBLE OF THUNDER
AS THERE IS SOME ELEVATED CAPE...BOTH THE GSO/RNK SOUNDINGS
SHOWING CAPE OF ABOUT 1000-1500 J/KG. WINDS ALOFT ARE RELATIVELY
WEAK...MEAN WIND OF ABOUT 10KTS/12MPH. AS SUCH STORM MOVEMENT IS
SLOW...THUS RESULTING IN PERSISTENCE OF HEAVY RAIN WHERE IT
HAPPENS TO OCCUR...SOME CASES RESULTING IN AN INCH OF RAIN IN LESS
THAN AN HOUR.
THROUGH THE OVERNIGHT...WILL SEE GREATEST CONCENTRATION OF
SHOWERS AND A FEW THUNDERSTORMS OVER THE PIEDMONT AS THE FRONT
ENTERS THE AREA AND WINDSPEEDS ALOFT DIMINISH. EXPECT THAT THE
ACTIVITY WILL REMAIN PULSY IN NATURE...ALTHOUGH WOULD NOT BE
SURPRISED TO SEE CLUSTERS OF SEMI-ORGANIZED CELLS WHERE OUTFLOW
BOUNDARIES MERGE. RAINFALL SHOULD DECREASE IN COVERAGE HEADING
INTO THE EARLY HOURS OF SATURDAY...THEN INCREASE AGAIN BY SATURDAY
AFTERNOON.
SHOWER AND THUNDERSTORM ACTIVITY WILL BECOME MORE WIDESPREAD
GOING INTO SATURDAY AFTERNOON AS THE UPPER LEVEL TROUGH MOVES
CLOSER. INCREASED CLOUD COVER AND SCATTERED RAINFALL WILL LIMIT
SURFACED BASED INSTABILITY...WITH AFTERNOON HIGHS HOLDING MAINLY
IN THE UPPER 60S TO MID 70S...SO DO NOT FORESEE A LARGE THREAT OF
SEVERE THUNDERSTORM ACTIVITY DURING THE AFTERNOON. HOWEVER...WEAK
UPPER LEVEL WINDS WILL RESULT IN SLOW MOVEMENT OF ANY STRONGER
SHOWERS AND STORMS...WHICH MAY LEAD TO LOCALLY HEAVY RAIN. BELIEVE
WE WILL HAVE A FEW AREAS OF LOCALIZED NUISANCE FLOODING WHERE
HEAVY RAIN DEVELOPS...BUT DO NOT FORESEE THE THREAT TO BE
WIDESPREAD ENOUGH AT THIS TIME TO GO WITH ANY SORT OF FLOOD WATCH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 330 PM EDT FRIDAY...
SLOW MOVING UPPER LOW/TROUGH WILL MAKE ITS WAY EASTWARD ALONG A
STALLED FRONTAL BOUNDARY. ITS PASSAGE WILL ALLOW FOR DAILY ORGANIZED
SHOWERS AND STORMS TO OCCUR ACROSS THE AREA. SOME WILL BE DRIVEN BY
THE DYNAMICS OF THE SYSTEM...THOSE OCCURRING DURING THE DAY WILL
BENEFIT FROM DAYTIME INSTABILITY AS WELL. THE AXIS OF THE SYSTEM IS
PROGGED TO LIFT NORTHEAST OF THE AREA LATE IN THE DAY MONDAY. WE
EXPECTED A GRADUAL DECREASE IN COVERAGE DURING THIS TIME
PERIOD...WITH THE GREATEST COVERAGE ACROSS THE EASTERN PART OF THE
FORECAST AREA.
TEMPERATURES WILL AVERAGE NEAR NORMAL...IF NOT A SLIGHTLY ABOVE
NORMAL ON AVERAGE GIVEN ELEVATED DEW POINT VALUES OVERNIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1100 PM EDT FRIDAY...
SURFACE FRONT OVER THE AREA WILL COMBINE WITH AN UPPER LEVEL
TROUGH RESULTING IN SCATTERED TO NUMEROUS SHOWERS THROUGH THE TAF
PERIOD. AN EASTERLY WIND WILL ALSO DEVELOP OVER THE
AREA...RESULTING IN THE FORMATION OF LOW LEVEL STRATUS. MODELS
SUGGEST CIGS MAY DROP INTO IFR CATEGORY BY SATURDAY MORNING. ATTM
WILL ADVERTISE MVFR CIGS WITH THINKING THAT ENOUGH MIXING SHOULD
TAKE PLACE FROM THE SHOWER ACTIVITY TO LIFT CIGS A BIT HIGHER THAN
MODEL FORECAST. AT THE VERY LEAST...MAY BE LOOKING AT OBSCD RIDGE
TOPS FROM THE LOWERING CLOUD BASE.
.AVIATION EXTENDED...
SIMILAR CONDITIONS EXPECTED SUNDAY WITH MVFR CONDITIONS AND LCL
IFR. CONDITIONS LOOK TO IMPROVE MONDAY AS THE UPPER TROUGH MOVES
TO ALONG THE MID ATLANTIC COAST. EXPECT TUESDAY TO BE THE BEST
BET FOR DECENT FLYING CONDITIONS THOUGH MOUNTAINS ALTHOUGH AN
ISOLATED AFTERNOON AIRMASS SHOWER OR STORM IS STILL POSSIBLE.
NEXT LAZY FRONT APPROACHES ON WEDNESDAY WITH MORE SHOWERS/STORMS
DEVELOPING. THIS FRONT DOES NOT APPEAR TO BE IN A BIG HURRY AND
LOOKS TO BRING MVRF CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF
SITES FOR THE LATTER HALF OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF/PM
SHORT TERM...DS
LONG TERM...DS
AVIATION...PM
000
FXUS61 KRNK 171958
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
358 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE SOUTH THIS EVENING AND
TONIGHT ACROSS THE EASTERN HALF OF THE FORECAST REGION...ALLOWING
WEAK HIGH PRESSURE TO WEDGE AGAINST THE MOUNTAINS. AN UPPER LEVEL
DISTURBANCE WILL ADVANCE TOWARD THE CENTRAL APPALACHIAN CHAIN ON
SATURDAY...INCREASING THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA. A DEEP UPPER LEVEL LOW PRESSURE SYSTEM WILL
APPROACH THE AREA TOWARD THE END OF THE COMING WEEK...WHICH MAY
BRING A RETURN OF COOLER WEATHER.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 400 PM EDT FRIDAY...
LATEST RADAR IMAGERY INDICATES SPOTTY SHOWER ACTIVITY THIS
AFTERNOON...MAINLY ACROSS THE MOUNTAINS...WITH ONLY A THUNDERSTORM
OR TWO IN THE MIX. WHERE WE HAVE BEEN OBSERVING THUNDERSTORMS
HOWEVER...A FEW HAVE BECOME STRONG ENOUGH TO PRODUCE SMALL
HAIL...SO WILL HAVE TO MONITOR THE INTENSITY OF ANY NEW STORMS
THROUGH THE EVENING NOW THAT WE ARE IN MAXIMUM DAYTIME HEATING.
JUST TO THE NORTH OF THE AREA...KEEPING AN EYE ON A COLD FRONT
WHICH HAS BEEN SINKING SLOWLY SOUTHWARD THROUGH THE DAY...AND IS
GETTING READY TO ENTER OUR NORTHERN TIER OF COUNTIES.
THROUGH THIS EVENING AND TONIGHT...WILL SEE SHOWERS AND A FEW
THUNDERSTORMS SPREAD TO THE PIEDMONTS AS THE FRONT ENTERS THE AREA
AND WINDSPEEDS ALOFT DIMINISH. EXPECT THAT THE ACTIVITY WILL
REMAIN PULSY IN NATURE...ALTHOUGH WOULD NOT BE SURPRISED TO SEE
MORE ORGANIZED DEVELOPMENT AHEAD OF THE FRONT FOR A FEW HOURS. NOT
THAT MUCH INSTABILITY FOR THESE STORMS TO WORK WITH...SO NOT
EXPECTING MUCH SEVERE ACTIVITY...ALTHOUGH CANNOT RULE OUT AT LEAST
ONE STRONG STORM. RAINFALL WILL DIMINISH IN COVERAGE HEADING INTO
THE EARLY HOURS OF SATURDAY...AND EXPECT TO SEE A FEW SHOWERS
LINGER THROUGH THE NIGHT AS AN UPPER TROUGH APPROACHES FROM THE
WEST...BUT COVERAGE WILL OVERALL DIMINISH. WITH THE SLIGHTLY
COOLER AND MORE STABLE AIR ENTERING THE PIEDMONTS BEHIND THE
FRONT...BELIEVE WE WILL SEE PATCHY FOG DEVELOP OVERNIGHT...
ESPECIALLY IN AREAS THAT RECEIVE RAINFALL THIS EVENING.
SHOWER AND THUNDERSTORM ACTIVITY WILL BECOME MORE WIDESPREAD GOING
INTO SATURDAY AFTERNOON AS THE UPPER LEVEL TROUGH MOVES CLOSER.
INCREASED CLOUD COVER AND SCATTERED RAINFALL WILL LIMIT SURFACED
BASED INSTABILITY...WITH AFTERNOON HIGHS HOLDING MAINLY IN THE
UPPER 60S TO MID 70S...SO DO NOT FORESEE A LARGE THREAT OF SEVERE
THUNDERSTORM ACTIVITY DURING THE AFTERNOON. HOWEVER...WEAK UPPER
LEVEL WINDS WILL RESULT IN SLOW MOVEMENT OF ANY STRONGER SHOWERS
AND STORMS...WHICH MAY LEAD TO LOCALLY HEAVY RAIN. BELIEVE WE WILL
HAVE A FEW AREAS OF LOCALIZED NUISANCE FLOODING WHERE HEAVY RAIN
DEVELOPS...BUT DO NOT FORESEE THE THREAT TO BE WIDESPREAD ENOUGH
AT THIS TIME TO GO WITH ANY SORT OF FLOOD WATCH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 330 PM EDT FRIDAY...
SLOW MOVING UPPER LOW/TROUGH WILL MAKE ITS WAY EASTWARD ALONG A
STALLED FRONTAL BOUNDARY. ITS PASSAGE WILL ALLOW FOR DAILY ORGANIZED
SHOWERS AND STORMS TO OCCUR ACROSS THE AREA. SOME WILL BE DRIVEN BY
THE DYNAMICS OF THE SYSTEM...THOSE OCCURRING DURING THE DAY WILL
BENEFIT FROM DAYTIME INSTABILITY AS WELL. THE AXIS OF THE SYSTEM IS
PROGGED TO LIFT NORTHEAST OF THE AREA LATE IN THE DAY MONDAY. WE
EXPECTED A GRADUAL DECREASE IN COVERAGE DURING THIS TIME
PERIOD...WITH THE GREATEST COVERAGE ACROSS THE EASTERN PART OF THE
FORECAST AREA.
TEMPERATURES WILL AVERAGE NEAR NORMAL...IF NOT A SLIGHTLY ABOVE
NORMAL ON AVERAGE GIVEN ELEVATED DEW POINT VALUES OVERNIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
MONDAY NIGHT...THE PROCESS OF DECREASING COVER THAT BEGAN ON MONDAY
WILL CONTINUE MONDAY NIGHT AS THE TROUGH CONTINUES HEADING OUT OF
THE REGION. ON TUESDAY...WE WILL BE BETWEEN SYSTEMS...WITH THE
POTENTIAL FOR A BRIEF PERIOD OF UPPER LEVEL RIDGING ACROSS THE
REGION. HOWEVER...LOW LEVELS WILL REMAIN ON THE ACTIVE SIDE AHEAD OF
THE NEXT APPROACHING SYSTEM.
THIS NEXT SYSTEM WILL BE AN UPPER LOW THAT WILL HAVE A MORE
NORTHERLY TRACK AS COMPARED TO THE ONE OVER THE WEEKEND.
HOWEVER...ITS PATH WILL ALLOW FOR A SOUTHERLY FETCH OF GULF OF
MEXICO MOISTURE TO STREAM INTO THE REGION WITH INCREASING CHANCE OF
SHOWERS AND STORMS THROUGH THE START OF FRIDAY. MODEL GUIDANCE
VARIES AS TO HOW QUICKLY THE ASSOCIATED COLD FRONT CROSSES THE
AREA...BUT CONSENSUS IS FAIRLY GOOD THAT LINGERING MOISTURE WILL
REMAIN OVER THE AREA ON THE BACKSIDE OF THE FRONT REGARDLESS OF THE
MODEL OF CHOICE. THIS EQUATES TO SHOWERS IN THE FORECAST THROUGH AT
LEAST FRIDAY.
TEMPERATURES WILL TREND MILDER THROUGH THE PERIOD THROUGH AT LEAST
WEDNESDAY...THEN START TO BE COOLER AS CLOUDS AND PRECIPITATION
BECOME MORE ABUNDANT.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 615 AM EDT FRIDAY...
HIGH PRESSURE WILL BE WEDGING DOWN THE EAST COAST THROUGH THE
PERIOD...PUSHING A WAVY FRONT INTO THE AREA AND LEAVING IT HERE
THROUGH THE WEEKEND. SAT LOOP SHOWED MAINLY MID LEVEL CLOUDS
ACROSS NORTHERN AND WESTERN PORTION OF THE REGION WITH A GOOD
DEAL OF CLEAR SKIES AND HEATING THROUGHOUT THE MORNING. BELIEVE
THERE IS ENOUGH MOISTURE IN PLACE FOR CONVECTION TO DEVELOP WITH
MTNS AND DIFFUSE FRONTAL BOUNDARY SERVING AS A LOW LEVEL FOCUS AND
A WEAK 500MB VORT LOBE AND SOME UL JET DYNAMICS AIDING FROM ABOVE.
BUFKIT SOUNDINGS SHOW LONG AND SKINNY CAPE WHICH IS NOT FAVORABLE
FOR SVR BUT INVERTED V SOUNDING INDICATES STORMS SHOULD BE
EFFICIENT PRODUCERS OF GUSTY WINDS.
EXPECTING A TYPICAL DIURNAL TIMING FOR BEST SHOT AT CONVECTION
FROM ABOUT 18Z TO ABOUT 02Z. WILL USE VCTS DURING THIS PERIOD AND
ATTEMPT TO CONFINE PREDOMINANT TS TO A MOST FAVORABLE HOUR OR TWO.
WRF MODEL SEEMED TO DO WELL WITH CONVECTION YESTERDAY AND WILL
LEAN ON IT FOR ANTICIPATED EVOLUTION TODAY.
DO NOT EXPECT WINDS TO BE PROBLEMATIC OUTSIDE OF CONVECTIVE
AREAS. MOS GUIDANCE IS SHOWING DEVELOPMENT OF LOW CLOUDS/FOG
OVERNIGHT AND BASED ON TREND FROM LWB LAST NIGHT THIS SEEMS
REASONABLE...ESPECIALLY FOR AREAS THAT RECEIVE DIRECT PCPN THIS
AFTERNOON.
BELIEVE WAVY NATURE OF FRONT MAY KEEP SHOWERS LINGERING THROUGH
THE OVERNIGHT BUT BEST CHANCE OF PCPN WILL WAIT UNTIL SATURDAY AS
THE BULK OF UPPER SHORT WAVE APPROACHES THE AREA...THOUGH TIMING
ON THIS WILL BE LATE IN THE PERIOD.
.AVIATION EXTENDED...
WEDGIE SITUATION WILL BRING ELY FLOW TO THE AREA SATURDAY
AFTERNOON THROUGH SUNDAY NIGHT. THIS WILL KEEP SITES IN A GOOD
CHANCE OF PCPN...ALONG WITH LOW CIGS/VSBYS AT NIGHT. CONDITIONS
LOOK TO IMPROVE AS THE HIGH NUDGES EAST AND SHOULD LET THE FRONTAL
BOUNDARY PUSH OFF TO OUR NORTH ON MONDAY. EXPECT TUESDAY TO BE THE
BEST BET FOR DECENT FLYING CONDITIONS THOUGH MOUNTAINS MAY HELP
FIRE SOME ISOLATED AFTERNOON SHOWERS/STORMS. NEXT LAZY FRONT
APPROACHES ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS
FRONT DOES NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVRF
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE END OF
THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...DS
LONG TERM...DS
AVIATION...MBS
000
FXUS61 KRNK 171807
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
207 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
TODAY BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY THIS EVENING. THE FRONT WILL STALL OVER NORTH CAROLINA
OVERNIGHT INTO SATURDAY NIGHT BEFORE LIFTING BACK NORTHEAST AS A
WARM FRONT BY EARLY NEXT WEEK. A WEAK UPPER LEVEL DISTURBANCE
WILL RIDE EAST ALONG THE FRONT ENHANCING THE THREAT FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT FRIDAY...
PLENTY OF SUNSHINE REACHING THE SURFACE THIS MORNING FOR MUCH OF
THE AREA OUTSIDE OF PORTIONS OF THE ALLEGHANY HIGHLANDS AND THE
SHENANDOAH VALLEY. THE INCREASED HEATING IS ALREADY LEADING TO A
FEW CU POPPING UP ALONG THE RIDGELINES...AND WILL HAVE TO MONITOR
THROUGH THE MORNING FOR THE DEVELOPMENT OF SHOWER ACTIVITY...AND
THUNDERSTORMS LATER IN THE DAY. MAINTAINING THE PREVIOUS FORECAST
PHILOSOPHY FOR TODAY...WHICH IS FOR SPOTTY SHOWERS AND
THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON ALONG THE RIDGES AS
SOUTHEASTERLY WINDS LEAD TO STRONGER LOW LEVEL CONVERGENCE...AND
THEN THUNDERSTORM ACTIVITY WILL BECOME MORE WIDESPREAD ACROSS THE
PIEDMONTS DURING THE EVENING AHEAD OF A FRONT THAT WILL BE SINKING
ACROSS THE AREA. BELIEVE THAT THUNDERSTORM ACTIVITY WILL BE MORE
PULSE LIKE IN NATURE...AND MAY BE SLOW MOVING DUE TO WEAK WINDS
ALOFT. AS SUCH...MAY SEE LOCALLY HEAVY RAIN IN A FEW AREAS IF
CELLS LINGER LONG ENOUGH OR IF THEY BEGIN TO TRAIN.
LINGERING INSTABILITY WILL GET SHOVED BACK TO ALONG AND WEST OF
THE BLUE RIDGE OVERNIGHT AS THE FRONT PASSES INTO THE FAR SOUTHERN
AREAS BY DAYBREAK. WILL HAVE CONTINUED HIGH POPS DURING THE
EVENING PENDING WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY TAKES
SHAPE...THEN DECREASING BY MIDNIGHT ESPECIALLY EAST IN THE WAKE
OF THE BOUNDARY. WESTERN AREAS MAY SEE SHOWERS INCREASE AGAIN
LATE AHEAD OF THE APPROACHING UPPER LOW BUT IFFY...SO ONLY KEEPING
CHANCE POPS GOING THERE. OTHERWISE MOSTLY CLOUDY AND MUGGY WITH
LOWS IN THE 50S TO LOWER 60S FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 349 AM EDT FRIDAY...
BOUNDARY JUST TO OUR NORTH WILL SINK SOUTH OVER THE WEEKEND...IN A
BACKDOOR FASHION AS HIGH PRESSURE SLIPS OVER NEW ENGLAND. THIS
BOUNDARY IN COMBINATION WITH SOUTHEAST UPSLOPE WINDS AGAINST THE
BLUE RIDGE...AND AN UPPER WAVE MOVING ACROSS TN...SHOULD PRODUCE A
SOMEWHAT COOL AND DAMP WEEKEND. SUNDAY APPEARS TO BE THE WETTEST DAY
WITH THE UPPER DISTURBANCE RIGHT ON OUR DOORSTEP THEN MOVING INTO
VIRGINIA DURING THE DAY. PWATS START OUT FAIR SATURDAY BUT REALLY
INCREASE SUNDAY TO 1.5" THROUGH THE PIEDMONT. WITH DEAD FLOW
ALOFT AND WEAK MBE VELOCITIES...STORMS MAY BE SLOW MOVING AND
LATCHED ONTO THE BLUE RIDGE...POSSIBLY LEADING TO SOME WATER
PROBLEMS. INSTABILITY ISN`T THE STRONGEST...AS SUNSHINE WILL BE
LIMITED BY ABUNDANT CLOUDS...BUT COOLING ALOFT THANKS TO THE UPPER
WAVE COULD LEAD TO A MINIMAL STRONG STORM THREAT...ALTHOUGH NOT
TOO THRILLED ABOUT SEVERE WEATHER. SURFACE WINDS VEER ON
MONDAY...MORE OF A S TO SSW WIND AS THE SHORTWAVE MOVES
EAST...THUS ONLY CHC POPS AND WARMER AFTERNOON TEMPS...ESPECIALLY
WEST OF THE BLUE RIDGE WITH LESS CLOUDS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 315 AM EDT FRIDAY...
FRONT LIFTS TO OUR NORTH TUESDAY WHICH SHOULD BE OUR BEST BET TO
AVOID PCPN GIVEN SOME SHORT WAVE RIDGING...THOUGH LOCAL MOUNTAIN
EFFECTS MAY STILL COOK UP SOME ISOLATED CONVECTION. NEXT FRONT
WILL BE APPROACHING FROM THE WEST ON WEDNESDAY SO EXPECT
INCREASING CHC OF THUNDER AS WE GET INTO WEDNESDAY AFTERNOON. THE
FRONT WANTS TO PUSH THROUGH AND CLEAR THE AREA FOR
THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW IT DOWN
AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL POSITION
THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 615 AM EDT FRIDAY...
HIGH PRESSURE WILL BE WEDGING DOWN THE EAST COAST THROUGH THE
PERIOD...PUSHING A WAVY FRONT INTO THE AREA AND LEAVING IT HERE
THROUGH THE WEEKEND. SAT LOOP SHOWED MAINLY MID LEVEL CLOUDS
ACROSS NORTHERN AND WESTERN PORTION OF THE REGION WITH A GOOD
DEAL OF CLEAR SKIES AND HEATING THROUGHOUT THE MORNING. BELIEVE
THERE IS ENOUGH MOISTURE IN PLACE FOR CONVECTION TO DEVELOP WITH
MTNS AND DIFFUSE FRONTAL BOUNDARY SERVING AS A LOW LEVEL FOCUS AND
A WEAK 500MB VORT LOBE AND SOME UL JET DYNAMICS AIDING FROM ABOVE.
BUFKIT SOUNDINGS SHOW LONG AND SKINNY CAPE WHICH IS NOT FAVORABLE
FOR SVR BUT INVERTED V SOUNDING INDICATES STORMS SHOULD BE
EFFICIENT PRODUCERS OF GUSTY WINDS.
EXPECTING A TYPICAL DIURNAL TIMING FOR BEST SHOT AT CONVECTION
FROM ABOUT 18Z TO ABOUT 02Z. WILL USE VCTS DURING THIS PERIOD AND
ATTEMPT TO CONFINE PREDOMINANT TS TO A MOST FAVORABLE HOUR OR TWO.
WRF MODEL SEEMED TO DO WELL WITH CONVECTION YESTERDAY AND WILL
LEAN ON IT FOR ANTICIPATED EVOLUTION TODAY.
DO NOT EXPECT WINDS TO BE PROBLEMATIC OUTSIDE OF CONVECTIVE
AREAS. MOS GUIDANCE IS SHOWING DEVELOPMENT OF LOW CLOUDS/FOG
OVERNIGHT AND BASED ON TREND FROM LWB LAST NIGHT THIS SEEMS
REASONABLE...ESPECIALLY FOR AREAS THAT RECEIVE DIRECT PCPN THIS
AFTERNOON.
BELIEVE WAVY NATURE OF FRONT MAY KEEP SHOWERS LINGERING THROUGH
THE OVERNIGHT BUT BEST CHANCE OF PCPN WILL WAIT UNTIL SATURDAY AS
THE BULK OF UPPER SHORT WAVE APPROACHES THE AREA...THOUGH TIMING
ON THIS WILL BE LATE IN THE PERIOD.
.AVIATION EXTENDED...
WEDGIE SITUATION WILL BRING ELY FLOW TO THE AREA SATURDAY
AFTERNOON THROUGH SUNDAY NIGHT. THIS WILL KEEP SITES IN A GOOD
CHANCE OF PCPN...ALONG WITH LOW CIGS/VSBYS AT NIGHT. CONDITIONS
LOOK TO IMPROVE AS THE HIGH NUDGES EAST AND SHOULD LET THE FRONTAL
BOUNDARY PUSH OFF TO OUR NORTH ON MONDAY. EXPECT TUESDAY TO BE THE
BEST BET FOR DECENT FLYING CONDITIONS THOUGH MOUNTAINS MAY HELP
FIRE SOME ISOLATED AFTERNOON SHOWERS/STORMS. NEXT LAZY FRONT
APPROACHES ON WEDNESDAY WITH MORE SHOWERS/STORMS DEVELOPING. THIS
FRONT DOES NOT APPEAR TO BE IN A BIG HURRY AND LOOKS TO BRING MVRF
CONDITIONS...POSSIBLY IFR AT NIGHT...TO TAF SITES FOR THE END OF
THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KM
LONG TERM...AMS/MBS
AVIATION...MBS
000
FXUS61 KRNK 171437
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1037 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
TODAY BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY THIS EVENING. THE FRONT WILL STALL OVER NORTH CAROLINA
OVERNIGHT INTO SATURDAY NIGHT BEFORE LIFTING BACK NORTHEAST AS A
WARM FRONT BY EARLY NEXT WEEK. A WEAK UPPER LEVEL DISTURBANCE
WILL RIDE EAST ALONG THE FRONT ENHANCING THE THREAT FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT FRIDAY...
PLENTY OF SUNSHINE REACHING THE SURFACE THIS MORNING FOR MUCH OF
THE AREA OUTSIDE OF PORTIONS OF THE ALLEGHANY HIGHLANDS AND THE
SHENANDOAH VALLEY. THE INCREASED HEATING IS ALREADY LEADING TO A
FEW CU POPPING UP ALONG THE RIDGELINES...AND WILL HAVE TO MONITOR
THROUGH THE MORNING FOR THE DEVELOPMENT OF SHOWER ACTIVITY...AND
THUNDERSTORMS LATER IN THE DAY. MAINTAINING THE PREVIOUS FORECAST
PHILOSOPHY FOR TODAY...WHICH IS FOR SPOTTY SHOWERS AND
THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON ALONG THE RIDGES AS
SOUTHEASTERLY WINDS LEAD TO STRONGER LOW LEVEL CONVERGENCE...AND
THEN THUNDERSTORM ACTIVITY WILL BECOME MORE WIDESPREAD ACROSS THE
PIEDMONTS DURING THE EVENING AHEAD OF A FRONT THAT WILL BE SINKING
ACROSS THE AREA. BELIEVE THAT THUNDERSTORM ACTIVITY WILL BE MORE
PULSE LIKE IN NATURE...AND MAY BE SLOW MOVING DUE TO WEAK WINDS
ALOFT. AS SUCH...MAY SEE LOCALLY HEAVY RAIN IN A FEW AREAS IF
CELLS LINGER LONG ENOUGH OR IF THEY BEGIN TO TRAIN.
LINGERING INSTABILITY WILL GET SHOVED BACK TO ALONG AND WEST OF
THE BLUE RIDGE OVERNIGHT AS THE FRONT PASSES INTO THE FAR SOUTHERN
AREAS BY DAYBREAK. WILL HAVE CONTINUED HIGH POPS DURING THE
EVENING PENDING WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY TAKES
SHAPE...THEN DECREASING BY MIDNIGHT ESPECIALLY EAST IN THE WAKE
OF THE BOUNDARY. WESTERN AREAS MAY SEE SHOWERS INCREASE AGAIN
LATE AHEAD OF THE APPROACHING UPPER LOW BUT IFFY...SO ONLY KEEPING
CHANCE POPS GOING THERE. OTHERWISE MOSTLY CLOUDY AND MUGGY WITH
LOWS IN THE 50S TO LOWER 60S FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 349 AM EDT FRIDAY...
BOUNDARY JUST TO OUR NORTH WILL SINK SOUTH OVER THE WEEKEND...IN A
BACKDOOR FASHION AS HIGH PRESSURE SLIPS OVER NEW ENGLAND. THIS
BOUNDARY IN COMBINATION WITH SOUTHEAST UPSLOPE WINDS AGAINST THE
BLUE RIDGE...AND AN UPPER WAVE MOVING ACROSS TN...SHOULD PRODUCE A
SOMEWHAT COOL AND DAMP WEEKEND. SUNDAY APPEARS TO BE THE WETTEST DAY
WITH THE UPPER DISTURBANCE RIGHT ON OUR DOORSTEP THEN MOVING INTO
VIRGINIA DURING THE DAY. PWATS START OUT FAIR SATURDAY BUT REALLY
INCREASE SUNDAY TO 1.5" THROUGH THE PIEDMONT. WITH DEAD FLOW
ALOFT AND WEAK MBE VELOCITIES...STORMS MAY BE SLOW MOVING AND
LATCHED ONTO THE BLUE RIDGE...POSSIBLY LEADING TO SOME WATER
PROBLEMS. INSTABILITY ISN`T THE STRONGEST...AS SUNSHINE WILL BE
LIMITED BY ABUNDANT CLOUDS...BUT COOLING ALOFT THANKS TO THE UPPER
WAVE COULD LEAD TO A MINIMAL STRONG STORM THREAT...ALTHOUGH NOT
TOO THRILLED ABOUT SEVERE WEATHER. SURFACE WINDS VEER ON
MONDAY...MORE OF A S TO SSW WIND AS THE SHORTWAVE MOVES
EAST...THUS ONLY CHC POPS AND WARMER AFTERNOON TEMPS...ESPECIALLY
WEST OF THE BLUE RIDGE WITH LESS CLOUDS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 315 AM EDT FRIDAY...
FRONT LIFTS TO OUR NORTH TUESDAY WHICH SHOULD BE OUR BEST BET TO
AVOID PCPN GIVEN SOME SHORT WAVE RIDGING...THOUGH LOCAL MOUNTAIN
EFFECTS MAY STILL COOK UP SOME ISOLATED CONVECTION. NEXT FRONT
WILL BE APPROACHING FROM THE WEST ON WEDNESDAY SO EXPECT
INCREASING CHC OF THUNDER AS WE GET INTO WEDNESDAY AFTERNOON. THE
FRONT WANTS TO PUSH THROUGH AND CLEAR THE AREA FOR
THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW IT DOWN
AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL POSITION
THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 615 AM EDT FRIDAY...
FOG EARLY THIS MORNING REMAINS LIMITED TO MAINLY THE VALLEYS
ACROSS THE NORTH/NW THAT EXPERIENCED HEAVY RAINFALL YESTERDAY
EVENING. OTRW EXPECTING MAINLY VFR OUTSIDE OF KLWB WHERE WILL SEE
AREAS OF LIFR/VLIFR IN FOG/STRATUS THROUGH MID MORNING. ELSW MAINLY
SCTD/BKN MID CLOUD CANOPY TO INIT WITH ONLY SPOTTY LOWER VSBYS
AND PERHAPS SOME STRATUS KLYH/KBCB VICINITY THAT WERE IN
PROXIMITY TO EVENING SHRA/TSRA.
WEAK BACKDOOR COLD FRONT TO THE NORTH WILL DRIFT SOUTH/SW TODAY
BEFORE STALLING NEAR THE BLUE RIDGE LATE IN THE DAY. THIS
COMBINED WITH INCREASING MOISTURE...HEATING AND OROGRAPHICS WILL
PROVIDE THE FOCUS FOR ADDED SHRA/TSRA BY EARLY AFTERNOON WITH SOME
OF THIS COVERAGE LINGERING AND SPREADING NE BY EVENING. APPEARS
THE SW TIER OF THE AREA WILL HAVE THE INITIAL BEST SHOT OF SEEING
CONVECTION BUT CANT RULE OUT AT LEAST CLUSTERS OF STORMS ACROSS
THE REGION BY LATE IN THE DAY. THUS WILL MAINTAIN THE GOING
VCSH/VCTS MENTION FROM KBCB/KROA WESTWARD EARLY FRIDAY AFTERNOON
AND THEN INCLUDE A PREVAILING MVFR MENTION OF TSRA AT MOST SITES
MAINLY DURING THE 19-00Z/2-8PM PERIOD. THINK EASTERN LOCATIONS
SUCH AS KLYH MAY SEE LESS OF A THREAT EARLY ON SO DELAYED
INCLUSION OF CONVECTION A FEW HOURS THERE. EXPECT COVERAGE TO
DIMINISH WITH LOSS OF HEATING THIS EVENING BUT STILL ENOUGH
INSTABILITY AROUND ESPCLY WESTERN LOCATIONS TO KEEP -SHRA GOING A
WHILE LONGER INTO THE EARLY OVERNIGHT.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KM
LONG TERM...AMS/MBS
AVIATION...JH/PM
000
FXUS61 KRNK 171043
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
643 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
TODAY BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY THIS EVENING. THE FRONT WILL STALL OVER NORTH CAROLINA
OVERNIGHT INTO SATURDAY NIGHT BEFORE LIFTING BACK NORTHEAST AS A
WARM FRONT BY EARLY NEXT WEEK. A WEAK UPPER LEVEL DISTURBANCE
WILL RIDE EAST ALONG THE FRONT ENHANCING THE THREAT FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT FRIDAY...
CONVECTIVE COVERAGE AGAIN THE MAIN CONCERN TODAY INTO
TONIGHT AS THE WEAK COLD FRONT TO THE NORTH DRIFTS SOUTH REACHING
THE BLUE RIDGE THIS EVENING. FORCING ALOFT RATHER WEAK AS WILL BE
IN BETWEEN THE OUTFLOW BAND THAT PASSED TO THE SE EARLIER AND
BETTER LIFT WITH THE RESIDUAL UPPER LOW WELL TO THE SW. HOWEVER
MODELS INDIDCATE DECENT LOW LEVEL CONVERGENCE STARTING OVER THE SW
EARLY ON PER SOUTH/SE FLOW AHEAD OF THE BOUNDARY AND IN AN AREA OF
HIGHER THETA-E. THIS SIMILAR TO THE LASTEST SPC AND HIGH RES ARW
MODELS BUT OVERALL GUIDANCE CONSENSUS LACKING PER SPREAD IN
GFS/NAM OUTPUT THIS AFTERNOON. BEST INSTABILITY APPEARS OVER THE
SOUTHERN AND SW AHEAD OF THE FRONT SO BOOSTED POPS FOR A PERIOD OF
LOW END CATEGORICAL ALONG THE BLUE RIDGE...WITH SOME OF THIS
COVERAGE SPILLING EAST AND GRADUALLY UNZIPPING IN CONJUNCTION WITH
THE SW MOVING BOUNDARY. THIS SUPPORTS KEEPING LIKELY POPS ELSW
THIS AFTERNOON ALTHOUGH SEVERE POTENTIAL LOOKS TO BE MORE PULSE
NATURE PER LESS DRY AIR ALOFT AND SMALLER DCAPES WITH MORE SLOWER
MOVING SHRA/TSRA LIKELY. KEPT HIGH TEMPS IN BETWEEN MET/MAV MOS AS
EXPECT A DECENT PERIOD OF HEATING AFTER EARLY MID DECK ERODES AND
BEFORE COVERAGE OF SHOWERS INCREASES.
LINGERING INSTABILITY WILL GET SHOVED BACK TO ALONG AND
WEST OF THE BLUE RIDGE OVERNIGHT AS THE FRONT PASSES INTO THE FAR
SOUTHERN AREAS BY DAYBREAK. WILL HAVE CONTINUED HIGH POPS DURING
THE EVENING PENDING WHERE MORE ORGANIZED TSRA TAKES SHAPE...THEN
DECREASING BY MIDNIGHT ESPCLY EAST IN THE WAKE OF THE BOUNDARY.
WESTERN AREAS MAY SEE SHRA INCREASE AGAIN LATE AHEAD OF THE
APPROACHING UPPER LOW BUT IFFY...SO ONLY KEEPING CHANCE POPS GOING
THERE. OTRW MOSTLY CLOUDY AND MUGGY WITH LOWS IN THE 50S TO LOWER
60S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 349 AM EDT FRIDAY...
BOUNDARY JUST TO OUR NORTH WILL SINK SOUTH OVER THE WEEKEND...IN A
BACKDOOR FASHION AS HIGH PRESSURE SLIPS OVER NEW ENGLAND. THIS
BOUNDARY IN COMBINATION WITH SOUTHEAST UPSLOPE WINDS AGAINST THE
BLUE RIDGE...AND AN UPPER WAVE MOVING ACROSS TN...SHOULD PRODUCE A
SOMEWHAT COOL AND DAMP WEEKEND. SUNDAY APPEARS TO BE THE WETTEST DAY
WITH THE UPPER DISTURBANCE RIGHT ON OUR DOORSTEP THEN MOVING INTO
VIRGINIA DURING THE DAY. PWATS START OUT FAIR SATURDAY BUT REALLY
INCREASE SUNDAY TO 1.5" THROUGH THE PIEDMONT. WITH DEAD FLOW
ALOFT AND WEAK MBE VELOCITIES...STORMS MAY BE SLOW MOVING AND
LATCHED ONTO THE BLUE RIDGE...POSSIBLY LEADING TO SOME WATER
PROBLEMS. INSTABILITY ISN`T THE STRONGEST...AS SUNSHINE WILL BE
LIMITED BY ABUNDANT CLOUDS...BUT COOLING ALOFT THANKS TO THE UPPER
WAVE COULD LEAD TO A MINIMAL STRONG STORM THREAT...ALTHOUGH NOT
TOO THRILLED ABOUT SEVERE WEATHER. SURFACE WINDS VEER ON
MONDAY...MORE OF A S TO SSW WIND AS THE SHORTWAVE MOVES
EAST...THUS ONLY CHC POPS AND WARMER AFTERNOON TEMPS...ESPECIALLY
WEST OF THE BLUE RIDGE WITH LESS CLOUDS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 315 AM EDT FRIDAY...
FRONT LIFTS TO OUR NORTH TUESDAY WHICH SHOULD BE OUR BEST BET TO
AVOID PCPN GIVEN SOME SHORT WAVE RIDGING...THOUGH LOCAL MOUNTAIN
EFFECTS MAY STILL COOK UP SOME ISOLATED CONVECTION. NEXT FRONT
WILL BE APPROACHING FROM THE WEST ON WEDNESDAY SO EXPECT
INCREASING CHC OF THUNDER AS WE GET INTO WEDNESDAY AFTERNOON. THE
FRONT WANTS TO PUSH THROUGH AND CLEAR THE AREA FOR
THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW IT DOWN
AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL POSITION
THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
AS OF 615 AM EDT FRIDAY...
FOG EARLY THIS MORNING REMAINS LIMITED TO MAINLY THE VALLEYS
ACROSS THE NORTH/NW THAT EXPERIENCED HEAVY RAINFALL YESTERDAY
EVENING. OTRW EXPECTING MAINLY VFR OUTSIDE OF KLWB WHERE WILL SEE
AREAS OF LIFR/VLIFR IN FOG/STRATUS THROUGH MID MORNING. ELSW MAINLY
SCTD/BKN MID CLOUD CANOPY TO INIT WITH ONLY SPOTTY LOWER VSBYS
AND PERHAPS SOME STRATUS KLYH/KBCB VICINITY THAT WERE IN
PROXIMITY TO EVENING SHRA/TSRA.
WEAK BACKDOOR COLD FRONT TO THE NORTH WILL DRIFT SOUTH/SW TODAY
BEFORE STALLING NEAR THE BLUE RIDGE LATE IN THE DAY. THIS
COMBINED WITH INCREASING MOISTURE...HEATING AND OROGRAPHICS WILL
PROVIDE THE FOCUS FOR ADDED SHRA/TSRA BY EARLY AFTERNOON WITH SOME
OF THIS COVERAGE LINGERING AND SPREADING NE BY EVENING. APPEARS
THE SW TIER OF THE AREA WILL HAVE THE INITIAL BEST SHOT OF SEEING
CONVECTION BUT CANT RULE OUT AT LEAST CLUSTERS OF STORMS ACROSS
THE REGION BY LATE IN THE DAY. THUS WILL MAINTAIN THE GOING
VCSH/VCTS MENTION FROM KBCB/KROA WESTWARD EARLY FRIDAY AFTERNOON
AND THEN INCLUDE A PREVAILING MVFR MENTION OF TSRA AT MOST SITES
MAINLY DURING THE 19-00Z/2-8PM PERIOD. THINK EASTERN LOCATIONS
SUCH AS KLYH MAY SEE LESS OF A THREAT EARLY ON SO DELAYED
INCLUSION OF CONVECTION A FEW HOURS THERE. EXPECT COVERAGE TO
DIMINISH WITH LOSS OF HEATING THIS EVENING BUT STILL ENOUGH
INSTABILITY AROUND ESPCLY WESTERN LOCATIONS TO KEEP -SHRA GOING A
WHILE LONGER INTO THE EARLY OVERNIGHT.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KM
LONG TERM...AMS/MBS
AVIATION...JH/PM
000
FXUS61 KRNK 170821 CCA
AFDRNK
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BLACKSBURG VA
421 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
TODAY BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY THIS EVENING. THE FRONT WILL STALL OVER NORTH CAROLINA
OVERNIGHT INTO SATURDAY NIGHT BEFORE LIFTING BACK NORTHEAST AS A
WARM FRONT BY EARLY NEXT WEEK. A WEAK UPPER LEVEL DISTURBANCE
WILL RIDE EAST ALONG THE FRONT ENHANCING THE THREAT FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT FRIDAY...
CONVECTIVE COVERAGE AGAIN THE MAIN CONCERN TODAY INTO
TONIGHT AS THE WEAK COLD FRONT TO THE NORTH DRIFTS SOUTH REACHING
THE BLUE RIDGE THIS EVENING. FORCING ALOFT RATHER WEAK AS WILL BE
IN BETWEEN THE OUTFLOW BAND THAT PASSED TO THE SE EARLIER AND
BETTER LIFT WITH THE RESIDUAL UPPER LOW WELL TO THE SW. HOWEVER
MODELS INDIDCATE DECENT LOW LEVEL CONVERGENCE STARTING OVER THE SW
EARLY ON PER SOUTH/SE FLOW AHEAD OF THE BOUNDARY AND IN AN AREA OF
HIGHER THETA-E. THIS SIMILAR TO THE LASTEST SPC AND HIGH RES ARW
MODELS BUT OVERALL GUIDANCE CONSENSUS LACKING PER SPREAD IN
GFS/NAM OUTPUT THIS AFTERNOON. BEST INSTABILITY APPEARS OVER THE
SOUTHERN AND SW AHEAD OF THE FRONT SO BOOSTED POPS FOR A PERIOD OF
LOW END CATEGORICAL ALONG THE BLUE RIDGE...WITH SOME OF THIS
COVERAGE SPILLING EAST AND GRADUALLY UNZIPPING IN CONJUNCTION WITH
THE SW MOVING BOUNDARY. THIS SUPPORTS KEEPING LIKELY POPS ELSW
THIS AFTERNOON ALTHOUGH SEVERE POTENTIAL LOOKS TO BE MORE PULSE
NATURE PER LESS DRY AIR ALOFT AND SMALLER DCAPES WITH MORE SLOWER
MOVING SHRA/TSRA LIKELY. KEPT HIGH TEMPS IN BETWEEN MET/MAV MOS AS
EXPECT A DECENT PERIOD OF HEATING AFTER EARLY MID DECK ERODES AND
BEFORE COVERAGE OF SHOWERS INCREASES.
LINGERING INSTABILITY WILL GET SHOVED BACK TO ALONG AND
WEST OF THE BLUE RIDGE OVERNIGHT AS THE FRONT PASSES INTO THE FAR
SOUTHERN AREAS BY DAYBREAK. WILL HAVE CONTINUED HIGH POPS DURING
THE EVENING PENDING WHERE MORE ORGANIZED TSRA TAKES SHAPE...THEN
DECREASING BY MIDNIGHT ESPCLY EAST IN THE WAKE OF THE BOUNDARY.
WESTERN AREAS MAY SEE SHRA INCREASE AGAIN LATE AHEAD OF THE
APPROACHING UPPER LOW BUT IFFY...SO ONLY KEEPING CHANCE POPS GOING
THERE. OTRW MOSTLY CLOUDY AND MUGGY WITH LOWS IN THE 50S TO LOWER
60S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 349 AM EDT FRIDAY...
BOUNDARY JUST TO OUR NORTH WILL SINK SOUTH OVER THE WEEKEND...IN A
BACKDOOR FASHION AS HIGH PRESSURE SLIPS OVER NEW ENGLAND. THIS
BOUNDARY IN COMBINATION WITH SOUTHEAST UPSLOPE WINDS AGAINST THE
BLUE RIDGE...AND AN UPPER WAVE MOVING ACROSS TN...SHOULD PRODUCE A
SOMEWHAT COOL AND DAMP WEEKEND. SUNDAY APPEARS TO BE THE WETTEST DAY
WITH THE UPPER DISTURBANCE RIGHT ON OUR DOORSTEP THEN MOVING INTO
VIRGINIA DURING THE DAY. PWATS START OUT FAIR SATURDAY BUT REALLY
INCREASE SUNDAY TO 1.5" THROUGH THE PIEDMONT. WITH DEAD FLOW
ALOFT AND WEAK MBE VELOCITIES...STORMS MAY BE SLOW MOVING AND
LATCHED ONTO THE BLUE RIDGE...POSSIBLY LEADING TO SOME WATER
PROBLEMS. INSTABILITY ISN`T THE STRONGEST...AS SUNSHINE WILL BE
LIMITED BY ABUNDANT CLOUDS...BUT COOLING ALOFT THANKS TO THE UPPER
WAVE COULD LEAD TO A MINIMAL STRONG STORM THREAT...ALTHOUGH NOT
TOO THRILLED ABOUT SEVERE WEATHER. SURFACE WINDS VEER ON
MONDAY...MORE OF A S TO SSW WIND AS THE SHORTWAVE MOVES
EAST...THUS ONLY CHC POPS AND WARMER AFTERNOON TEMPS...ESPECIALLY
WEST OF THE BLUE RIDGE WITH LESS CLOUDS.
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 415 AM EDT FRIDAY...
FRONT LIFTS TO OUR NORTH TUESDAY WHICH SHOULD BE OUR BEST BET TO
AVOID PCPN GIVEN SOME SHORT WAVE RIDGING...THOUGH LOCAL MOUNTAIN
EFFECTS MAY STILL COOK UP SOME ISOLATED CONVECTION. NEXT FRONT
WILL BE APPROACHING FROM THE WEST ON WEDNESDAY SO EXPECT
INCREASING CHC OF THUNDER AS WE GET INTO WEDNESDAY AFTERNOON. THE
FRONT WANTS TO PUSH THROUGH AND CLEAR THE AREA FOR
THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW IT DOWN
AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL POSITION
THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 104 AM EDT FRIDAY...
EXPECTING OVERALL VFR OUTSIDE OF THE NW VALLEYS WHERE WILL SEE
AREAS OF IFR/LIFR IN FOG STRATUS DEVELOP THROUGH EARLY FRIDAY
MORNING. COULD SEE KLWB EVEN LOWER TO VLIFR BY DAYBREAK. OTRW
MAINLY SCTD/BKN HIGH/MID CLOUDS INTO EARLY FRIDAY MORNING WITH
SPOTS OF LOWER VSBYS AND PERHAPS SOME STRATUS TAKING SHAPE AROUND
KLYH AND KBCB THAT WERE IN PROXIMITY TO EVENING SHRA/TSRA.
WEAK BACKDOOR COLD FRONT TO THE NORTH WILL DRIFT SOUTH/SW ON
FRIDAY BEFORE STALLING NEAR THE BLUE RIDGE LATE IN THE DAY. THIS
COMBINED WITH INCREASING MOISTURE...HEATING AND OROGRAPHICS WILL
PROVIDE THE FOCUS FOR ADDED SHRA/TSRA BY EARLY AFTERNOON WITH SOME
OF THIS COVERAGE LINGERING AND SPREADING NE BY EVENING. APPEARS
THE SW TIER OF THE AREA WILL HAVE THE INITIAL BEST SHOT OF SEEING
CONVECTION BUT CANT RULE OUT AT LEAST CLUSTERS OF STORMS ACROSS
THE REGION BY LATE IN THE DAY. THUS WILL MAINTAIN THE GOING
VCSH/VCTS MENTION FROM KBCB/KROA WESTWARD EARLY FRIDAY AFTERNOON
AND THEN INCLUDE A PREVAILING MVFR MENTION OF TSRA AT MOST SITES
MAINLY DURING THE 19-00Z/2-8PM PERIOD. THINK EASTERN LOCATIONS
SUCH AS KLYH MAY SEE LESS OF A THREAT EARLY ON SO DELAYED
INCLUSION OF CONVECTION A FEW HOURS THERE. EXPECT COVERAGE TO
DIMINISH WITH LOSS OF HEATING FRIDAY EVENING BUT STILL ENOUGH
INSTABILITY AROUND ESPCLY SOUTH/SW SECTIONS TO KEEP -SHRA GOING A
WHILE LONGER INTO THE EARLY OVERNIGHT.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KM
LONG TERM...AMS/MBS
AVIATION...JH/PM
000
FXUS61 KRNK 170821
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
421 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
TODAY BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY THIS EVENING. THE FRONT WILL STALL OVER NORTH CAROLINA
OVERNIGHT INTO SATURDAY NIGHT BEFORE LIFTING BACK NORTHEAST AS A
WARM FRONT BY EARLY NEXT WEEK. A WEAK UPPER LEVEL DISTURBANCE
WILL RIDE EAST ALONG THE FRONT ENHANCING THE THREAT FOR SHOWERS
AND THUNDERSTORMS ESPECIALLY OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT FRIDAY...
CONVECTIVE COVERAGE AGAIN THE MAIN CONCERN TODAY INTO
TONIGHT AS THE WEAK COLD FRONT TO THE NORTH DRIFTS SOUTH REACHING
THE BLUE RIDGE THIS EVENING. FORCING ALOFT RATHER WEAK AS WILL BE
IN BETWEEN THE OUTFLOW BAND THAT PASSED TO THE SE EARLIER AND
BETTER LIFT WITH THE RESIDUAL UPPER LOW WELL TO THE SW. HOWEVER
MODELS INDIDCATE DECENT LOW LEVEL CONVERGENCE STARTING OVER THE SW
EARLY ON PER SOUTH/SE FLOW AHEAD OF THE BOUNDARY AND IN AN AREA OF
HIGHER THETA-E. THIS SIMILAR TO THE LASTEST SPC AND HIGH RES ARW
MODELS BUT OVERALL GUIDANCE CONSENSUS LACKING PER SPREAD IN
GFS/NAM OUTPUT THIS AFTERNOON. BEST INSTABILITY APPEARS OVER THE
SOUTHERN AND SW AHEAD OF THE FRONT SO BOOSTED POPS FOR A PERIOD OF
LOW END CATEGORICAL ALONG THE BLUE RIDGE...WITH SOME OF THIS
COVERAGE SPILLING EAST AND GRADUALLY UNZIPPING IN CONJUNCTION WITH
THE SW MOVING BOUNDARY. THIS SUPPORTS KEEPING LIKELY POPS ELSW
THIS AFTERNOON ALTHOUGH SEVERE POTENTIAL LOOKS TO BE MORE PULSE
NATURE PER LESS DRY AIR ALOFT AND SMALLER DCAPES WITH MORE SLOWER
MOVING SHRA/TSRA LIKELY. KEPT HIGH TEMPS IN BETWEEN MET/MAV MOS AS
EXPECT A DECENT PERIOD OF HEATING AFTER EARLY MID DECK ERODES AND
BEFORE COVERAGE OF SHOWERS INCREASES.
LINGERING INSTABILITY WILL GET SHOVED BACK TO ALONG AND
WEST OF THE BLUE RIDGE OVERNIGHT AS THE FRONT PASSES INTO THE FAR
SOUTHERN AREAS BY DAYBREAK. WILL HAVE CONTINUED HIGH POPS DURING
THE EVENING PENDING WHERE MORE ORGANIZED TSRA TAKES SHAPE...THEN
DECREASING BY MIDNIGHT ESPCLY EAST IN THE WAKE OF THE BOUNDARY.
WESTERN AREAS MAY SEE SHRA INCREASE AGAIN LATE AHEAD OF THE
APPROACHING UPPER LOW BUT IFFY...SO ONLY KEEPING CHANCE POPS GOING
THERE. OTRW MOSTLY CLOUDY AND MUGGY WITH LOWS IN THE 50S TO LOWER
60S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 349 AM EDT FRIDAY...
BOUNDARY JUST TO OUR NORTH WILL SINK SOUTH OVER THE WEEKEND...IN A
BACKDOOR FASHION AS HIGH PRESSURE SLIPS OVER NEW ENGLAND. THIS
BOUNDARY IN COMBINATION WITH SOUTHEAST UPSLOPE WINDS AGAINST THE
BLUE RIDGE...AND AN UPPER WAVE MOVING ACROSS TN...SHOULD PRODUCE A
SOMEWHAT COOL AND DAMP WEEKEND. SUNDAY APPEARS TO BE THE WETTEST DAY
WITH THE UPPER DISTURBANCE RIGHT ON OUR DOORSTEP THEN MOVING INTO
VIRGINIA DURING THE DAY. PWATS START OUT FAIR SATURDAY BUT REALLY
INCREASE SUNDAY TO 1/5" IN SPOTS. WITH DEAD FLOW ALOFT AND WEAK MBE
VELOCITIES...STORMS MAY BE SLOW MOVING AND LATCHED ONTO THE BLUE
RIDGE...POSSIBLY LEADING TO SOME WATER PROBLEMS. INSTABILITY ISN`T
THE STRONGEST...AS SUNSHINE WILL BE LIMITED BY ABUNDANT CLOUDS...BUT
COOLING ALOFT THANKS TO THE UPPER WAVE COULD LEAD TO A MINIMAL
STRONG STORM THREAT...ALTHOUGH NOT TOO THRILLED ABOUT SEVERE
WEATHER. SURFACE WINDS VEER ON MONDAY...MORE OF A S TO SSW WIND AS
THE SHORTWAVE MOVES EAST...THUS ONLY CHC POPS AND WARMER AFTERNOON
TEMPS...ESPECIALLY WEST OF THE BLUE RIDGE WITH LESS CLOUDS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 415 AM EDT FRIDAY...
FRONT LIFTS TO OUR NORTH TUESDAY WHICH SHOULD BE OUR BEST BET TO
AVOID PCPN GIVEN SOME SHORT WAVE RIDGING...THOUGH LOCAL MOUNTAIN
EFFECTS MAY STILL COOK UP SOME ISOLATED CONVECTION. NEXT FRONT
WILL BE APPROACHING FROM THE WEST ON WEDNESDAY SO EXPECT
INCREASING CHC OF THUNDER AS WE GET INTO WEDNESDAY AFTERNOON. THE
FRONT WANTS TO PUSH THROUGH AND CLEAR THE AREA FOR
THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW IT DOWN
AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL POSITION
THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 104 AM EDT FRIDAY...
EXPECTING OVERALL VFR OUTSIDE OF THE NW VALLEYS WHERE WILL SEE
AREAS OF IFR/LIFR IN FOG STRATUS DEVELOP THROUGH EARLY FRIDAY
MORNING. COULD SEE KLWB EVEN LOWER TO VLIFR BY DAYBREAK. OTRW
MAINLY SCTD/BKN HIGH/MID CLOUDS INTO EARLY FRIDAY MORNING WITH
SPOTS OF LOWER VSBYS AND PERHAPS SOME STRATUS TAKING SHAPE AROUND
KLYH AND KBCB THAT WERE IN PROXIMITY TO EVENING SHRA/TSRA.
WEAK BACKDOOR COLD FRONT TO THE NORTH WILL DRIFT SOUTH/SW ON
FRIDAY BEFORE STALLING NEAR THE BLUE RIDGE LATE IN THE DAY. THIS
COMBINED WITH INCREASING MOISTURE...HEATING AND OROGRAPHICS WILL
PROVIDE THE FOCUS FOR ADDED SHRA/TSRA BY EARLY AFTERNOON WITH SOME
OF THIS COVERAGE LINGERING AND SPREADING NE BY EVENING. APPEARS
THE SW TIER OF THE AREA WILL HAVE THE INITIAL BEST SHOT OF SEEING
CONVECTION BUT CANT RULE OUT AT LEAST CLUSTERS OF STORMS ACROSS
THE REGION BY LATE IN THE DAY. THUS WILL MAINTAIN THE GOING
VCSH/VCTS MENTION FROM KBCB/KROA WESTWARD EARLY FRIDAY AFTERNOON
AND THEN INCLUDE A PREVAILING MVFR MENTION OF TSRA AT MOST SITES
MAINLY DURING THE 19-00Z/2-8PM PERIOD. THINK EASTERN LOCATIONS
SUCH AS KLYH MAY SEE LESS OF A THREAT EARLY ON SO DELAYED
INCLUSION OF CONVECTION A FEW HOURS THERE. EXPECT COVERAGE TO
DIMINISH WITH LOSS OF HEATING FRIDAY EVENING BUT STILL ENOUGH
INSTABILITY AROUND ESPCLY SOUTH/SW SECTIONS TO KEEP -SHRA GOING A
WHILE LONGER INTO THE EARLY OVERNIGHT.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KM
LONG TERM...AMS/MBS
AVIATION...JH/PM
000
FXUS61 KRNK 170520
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
120 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK SOUTH TOWARD THE REGION
OVERNIGHT BEFORE SETTLING ACROSS THE EASTERN HALF OF THE FORECAST
AREA BY FRIDAY AFTERNOON. THE FRONT WILL REMAIN IN THE AREA
THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SHOWER AND
THUNDERSTORM ACTIVITY...MAINLY DURING THE AFTERNOON AND EVENING
HOURS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1100 PM EDT THURSDAY...
PRECIP HAS PRETTY MUCH ENDED FOR THE OVERNIGHT. CAN`T RULE OUT A
LATE NIGHT SHOWER PER LINGERING ELEVATED INSTABILITY (CAPE)...AND
WILL MAINTAIN LOW CHC POP TO ACCOUNT FOR THIS. SOME LATE NIGHT FOG
IS ALSO A GOOD POSSIBILITY FOR AREAS WHICH RECIEVED RAINFALL...ESP
THE GREENBRIER VALLEY OF WV.
MODELS ARE PROGGING A COLD FRONT TO SINK SOUTHWARD...EAST OF THE
BLUE RIDGE...BY LATE FRIDAY MORNING...BRINGING A LIGHT NORTHEASTERLY
WINDFLOW ACROSS THE AREA.
FOR FRIDAY...SHOWER ACTIVITY WILL BE MORE WIDESPREAD DURING THE
AFTERNOON AND EVENING WITH THE FRONT SITUATED ACROSS THE AREA.
INCREASED CLOUD COVER WILL ALSO LIMIT AFTERNOON HEATING...KEEPING
HIGHS CONFINED TO THE UPPER 70S WEST AND THE LOW 80S EAST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 300 PM EDT THURSDAY...
A RATHER OBNOXIOUS PATTERN SHAPING UP THROUGH THE FORECAST
PERIOD. UPPER TROF OVER THE MID WEST WILL BE OPENING UP AS BITS OF
ENERGY GET EJECTED TOWARD US. DIFFUSE FRONTAL BOUNDARY AT THE SFC
WILL ALSO BE WAFFLING BACK AND FORTH WITH NO BIG KICKER TO PUSH IT
CLEAR WHILE HIGH PRESSURE BEGINS TO WEDGE DOWN THE ERN SEABOARD.
EXPECT CONVECTION THAT FIRES TOMORROW WILL LINGER INTO THE
EVENING BEFORE GRADUALLY DIMINISHING OVERNIGHT AS HIGH PRESSURE
WEDGES DOWN THE EAST COAST. EXPECTING ENHANCED POPS ALONG THE BLUE
RIDGE AS E/SELY FLOW SETS UP. AFTER A BRIEF LULL EARLY SATURDAY
MORNING...EXPECT MORE CONVECTION TO DEVELOP WITH DIFFUSE FRONT IN
THE AREA AND WEAK LOW PRESSURE APPROACHING FROM THE WEST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODELS BEGIN TO DIVERGE IN THE EXTENDED AS THE EURO DEVELOPS AN
OMEGA BLOCK AND DIGS A CUTOFF OVER THE EAST COAST. THE GFS HAS
SIMILAR MORPHOLOGY BUT IS MUCH LESS AGGRESSIVE WITH THE TROF IN
THE EAST. WILL LEAN TOWARD A EURO SOLUTION FOR THE FORECAST.
EXPECT THE WEDGE SITUATION TO REMAIN IN PLACE THROUGH MONDAY WITH
DIURNAL TRENDS LEADING TO CHC/LKLY POPS WITH THUNDER THROUGH
MONDAY. IT LOOKS LIKE THE HIGH WILL FINALLY EDGE FAR ENOUGH TO THE
EAST LATE MONDAY TO NUDGE THE FRONT NORTH THROUGH OUR AREA AND GET
US INTO THE WARM SECTOR. BELIEVE TUESDAY WILL BE OUR BEST BET TO
AVOID PCPN WITH FRONT TO OUR NORTH AND SOME SHORT WAVE
RIDGING...THOUGH LOCAL MOUNTAIN EFFECTS MAY STILL COOK UP SOME
ISOLATED CONVECTION. NEXT FRONT WILL BE APPROACHING FROM THE WEST
ON WEDNESDAY SO EXPECT INCREASING CHC OF THUNDER AS WE GET INTO
WEDNESDAY AFTERNOON. THE FRONT WANTS TO PUSH THROUGH AND CLEAR THE
AREA FOR THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW
IT DOWN AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL
POSITION THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
AS OF 104 AM EDT FRIDAY...
EXPECTING OVERALL VFR OUTSIDE OF THE NW VALLEYS WHERE WILL SEE
AREAS OF IFR/LIFR IN FOG STRATUS DEVELOP THROUGH EARLY FRIDAY
MORNING. COULD SEE KLWB EVEN LOWER TO VLIFR BY DAYBREAK. OTRW
MAINLY SCTD/BKN HIGH/MID CLOUDS INTO EARLY FRIDAY MORNING WITH
SPOTS OF LOWER VSBYS AND PERHAPS SOME STRATUS TAKING SHAPE AROUND
KLYH AND KBCB THAT WERE IN PROXIMITY TO EVENING SHRA/TSRA.
WEAK BACKDOOR COLD FRONT TO THE NORTH WILL DRIFT SOUTH/SW ON
FRIDAY BEFORE STALLING NEAR THE BLUE RIDGE LATE IN THE DAY. THIS
COMBINED WITH INCREASING MOISTURE...HEATING AND OROGRAPHICS WILL
PROVIDE THE FOCUS FOR ADDED SHRA/TSRA BY EARLY AFTERNOON WITH SOME
OF THIS COVERAGE LINGERING AND SPREADING NE BY EVENING. APPEARS
THE SW TIER OF THE AREA WILL HAVE THE INITIAL BEST SHOT OF SEEING
CONVECTION BUT CANT RULE OUT AT LEAST CLUSTERS OF STORMS ACROSS
THE REGION BY LATE IN THE DAY. THUS WILL MAINTAIN THE GOING
VCSH/VCTS MENTION FROM KBCB/KROA WESTWARD EARLY FRIDAY AFTERNOON
AND THEN INCLUDE A PREVAILING MVFR MENTION OF TSRA AT MOST SITES
MAINLY DURING THE 19-00Z/2-8PM PERIOD. THINK EASTERN LOCATIONS
SUCH AS KLYH MAY SEE LESS OF A THREAT EARLY ON SO DELAYED
INCLUSION OF CONVECTION A FEW HOURS THERE. EXPECT COVERAGE TO
DIMINISH WITH LOSS OF HEATING FRIDAY EVENING BUT STILL ENOUGH
INSTABILITY AROUND ESPCLY SOUTH/SW SECTIONS TO KEEP -SHRA GOING A
WHILE LONGER INTO THE EARLY OVERNIGHT.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...PM
SHORT TERM...MBS
LONG TERM...AMS/MBS
AVIATION...JH/PM
000
FXUS61 KRNK 170315
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1115 PM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK FROM THE OHIO RIVER VALLEY
THROUGH THE EVENING...AND WILL SETTLE ACROSS THE EASTERN HALF OF
THE FORECAST AREA BY FRIDAY AFTERNOON. THE FRONT WILL REMAIN IN
THE AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY
SHOWER AND THUNDERSTORM ACTIVITY...MAINLY DURING THE AFTERNOON
AND EVENING HOURS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1100 PM EDT THURSDAY...
PRECIP HAS PRETTY MUCH ENDED FOR THE OVERNIGHT. CAN`T RULE OUT A
LATE NIGHT SHOWER PER LINGERING ELEVATED INSTABILITY (CAPE)...AND
WILL MAINTAIN LOW CHC POP TO ACCOUNT FOR THIS. SOME LATE NIGHT FOG
IS ALSO A GOOD POSSIBILITY FOR AREAS WHICH RECIEVED RAINFALL...ESP
THE GREENBRIER VALLEY OF WV.
MODELS ARE PROGGING A COLD FRONT TO SINK SOUTHWARD...EAST OF THE
BLUE RIDGE...BY LATE FRIDAY MORNING...BRINGING A LIGHT NORTHEASTERLY
WINDFLOW ACROSS THE AREA.
FOR FRIDAY...SHOWER ACTIVITY WILL BE MORE WIDESPREAD DURING THE
AFTERNOON AND EVENING WITH THE FRONT SITUATED ACROSS THE AREA.
INCREASED CLOUD COVER WILL ALSO LIMIT AFTERNOON HEATING...KEEPING
HIGHS CONFINED TO THE UPPER 70S WEST AND THE LOW 80S EAST.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 300 PM EDT THURSDAY...
A RATHER OBNOXIOUS PATTERN SHAPING UP THROUGH THE FORECAST
PERIOD. UPPER TROF OVER THE MID WEST WILL BE OPENING UP AS BITS OF
ENERGY GET EJECTED TOWARD US. DIFFUSE FRONTAL BOUNDARY AT THE SFC
WILL ALSO BE WAFFLING BACK AND FORTH WITH NO BIG KICKER TO PUSH IT
CLEAR WHILE HIGH PRESSURE BEGINS TO WEDGE DOWN THE ERN SEABOARD.
EXPECT CONVECTION THAT FIRES TOMORROW WILL LINGER INTO THE
EVENING BEFORE GRADUALLY DIMINISHING OVERNIGHT AS HIGH PRESSURE
WEDGES DOWN THE EAST COAST. EXPECTING ENHANCED POPS ALONG THE BLUE
RIDGE AS E/SELY FLOW SETS UP. AFTER A BRIEF LULL EARLY SATURDAY
MORNING...EXPECT MORE CONVECTION TO DEVELOP WITH DIFFUSE FRONT IN
THE AREA AND WEAK LOW PRESSURE APPROACHING FROM THE WEST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODELS BEGIN TO DIVERGE IN THE EXTENDED AS THE EURO DEVELOPS AN
OMEGA BLOCK AND DIGS A CUTOFF OVER THE EAST COAST. THE GFS HAS
SIMILAR MORPHOLOGY BUT IS MUCH LESS AGGRESSIVE WITH THE TROF IN
THE EAST. WILL LEAN TOWARD A EURO SOLUTION FOR THE FORECAST.
EXPECT THE WEDGE SITUATION TO REMAIN IN PLACE THROUGH MONDAY WITH
DIURNAL TRENDS LEADING TO CHC/LKLY POPS WITH THUNDER THROUGH
MONDAY. IT LOOKS LIKE THE HIGH WILL FINALLY EDGE FAR ENOUGH TO THE
EAST LATE MONDAY TO NUDGE THE FRONT NORTH THROUGH OUR AREA AND GET
US INTO THE WARM SECTOR. BELIEVE TUESDAY WILL BE OUR BEST BET TO
AVOID PCPN WITH FRONT TO OUR NORTH AND SOME SHORT WAVE
RIDGING...THOUGH LOCAL MOUNTAIN EFFECTS MAY STILL COOK UP SOME
ISOLATED CONVECTION. NEXT FRONT WILL BE APPROACHING FROM THE WEST
ON WEDNESDAY SO EXPECT INCREASING CHC OF THUNDER AS WE GET INTO
WEDNESDAY AFTERNOON. THE FRONT WANTS TO PUSH THROUGH AND CLEAR THE
AREA FOR THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW
IT DOWN AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL
POSITION THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 800 PM EDT THURSDAY...
SCT-BKN BAND OF SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE
TO WORK ITS WAY ACROSS THE AREA EARLY THIS EVENING AND WEEKEND.
STRONGEST SFC GUSTS THAT WE HAVE OBSERVED FROM ANY OF THIS
ACTIVITY HAS BEEN ABOUT 30 KTS. RISK WILL CONTINUE FOR A FEW MORE
HOURS...THROUGH ABOUT 02Z/10PM...B4 ACTIVITY FADES TO JUST AN
AREA OF MID/UPPER LEVEL CLOUDINESS. OUTSIDE OF THE AREA OF
SHRA/TSTM ACTIVITY...CONDITIONS WERE PRIMARILY VFR. THESE VFR
CONDITIONS SHOULD PERSIST UNTIL SKIES CLEAR TOWARD MORNING. WITH
ANY CLEARING...EXPECT AREAS OF FOG...ESP AREAS WHICH RECEIVED
RAIN...SUCH AS KLWB.
DURING THE OVERNIGHT...A COLD FRONT WILL PUSH SOUTHWARD FROM
NORTHERN VIRGINIA...PASSING ACROSS LYH AND DAN...AND ADVANCING
CLOSE TO ROA. WITH THE WEAKLY STABLE AIRMASS IN PLACE...EXPECT A
LIGHT NORTHEASTERLY FLOW. ON FRIDAY...WITH DAYTIME HEATING...THE
FRONTAL BOUNDARY DRAPED ACROSS OUR AREA WILL PROVIDE THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS...BUT MAINLY DURING THE
AFTERNOON.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...PM
SHORT TERM...MBS
LONG TERM...AMS/MBS
AVIATION...PM
000
FXUS61 KRNK 170004
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
804 PM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK FROM THE OHIO RIVER VALLEY
THROUGH THE EVENING...AND WILL SETTLE ACROSS THE EASTERN HALF OF
THE FORECAST AREA BY FRIDAY AFTERNOON. THE FRONT WILL REMAIN IN
THE AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY
SHOWER AND THUNDERSTORM ACTIVITY...MAINLY DURING THE AFTERNOON
AND EVENING HOURS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 400 PM EDT THURSDAY...
RADAR INDICATES A BAND OF SHOWERS AND THUNDERSTORMS ACROSS OUR
NORTHERN TIER OF COUNTIES THIS AFTERNOON...A FEW OF WHICH HAVE
BECOME STRONG TO BORDERLINE SEVERE. EXPECT THESE SHOWERS AND
THUNDERSTORMS TO SINK SOUTH ACROSS THE AREA THROUGH THE
EVENING...BUT TO WEAKEN AFTER SUNSET WITH THE LOSS OF DAYTIME
HEATING. TOWARD SUNSET...BELIEVE WESTERLY WINDS WILL DIMINISH IN
SPEED...WHICH WILL ERODE THE CAP OVERHEAD AND ALLOW A FEW MORE
SHOWERS/THUNDERSTORMS TO DEVELOP FURTHER SOUTH ACROSS THE
AREA...BUT THIS ACTIVITY SHOULD REMAIN SHORTLIVED. BY
MIDNIGHT...EXPECT ONLY LINGERING SHOWER ACTIVITY MAINLY NORTH OF
THE HIGHWAY 460 CORRIDOR.
CLOUD COVER WILL REMAIN WIDESPREAD THROUGH THE NIGHT...AND WITH
MOISTURE/WARM AIR CONVERGENCE AHEAD OF THE FRONT...WILL BE LOOKING
AT A WARM/MUGGY NIGHT WITH TEMPERATURES MAINLY UPPER 50S TO LOWER
60S. MODELS PROG THE COLD FRONT SINKING SOUTHWARD...EAST OF THE
BLUE RIDGE...BY LATE FRIDAY MORNING...BRINGING A LIGHT NORTHEASTERLY
WINDFLOW ACROSS THE AREA. MAY SEE PATCHY FOG DEVELOP IN THE MORE
STABLE AIRMASS ACROSS THE PIEDMONTS...WHICH WILL BURN OFF SHORTLY
AFTER SUNRISE.
SHOWER ACTIVITY WILL BE MORE WIDESPREAD DURING THE AFTERNOON AND
EVENING WITH THE FRONT SITUATED ACROSS THE AREA. INCREASED CLOUD
COVER WILL ALSO LIMIT AFTERNOON HEATING...KEEPING HIGHS CONFINED
TO THE UPPER 70S WEST AND THE LOW 80S EAST.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 300 PM EDT THURSDAY...
A RATHER OBNOXIOUS PATTERN SHAPING UP THROUGH THE FORECAST
PERIOD. UPPER TROF OVER THE MID WEST WILL BE OPENING UP AS BITS OF
ENERGY GET EJECTED TOWARD US. DIFFUSE FRONTAL BOUNDARY AT THE SFC
WILL ALSO BE WAFFLING BACK AND FORTH WITH NO BIG KICKER TO PUSH IT
CLEAR WHILE HIGH PRESSURE BEGINS TO WEDGE DOWN THE ERN SEABOARD.
EXPECT CONVECTION THAT FIRES TOMORROW WILL LINGER INTO THE
EVENING BEFORE GRADUALLY DIMINISHING OVERNIGHT AS HIGH PRESSURE
WEDGES DOWN THE EAST COAST. EXPECTING ENHANCED POPS ALONG THE BLUE
RIDGE AS E/SELY FLOW SETS UP. AFTER A BRIEF LULL EARLY SATURDAY
MORNING...EXPECT MORE CONVECTION TO DEVELOP WITH DIFFUSE FRONT IN
THE AREA AND WEAK LOW PRESSURE APPROACHING FROM THE WEST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODELS BEGIN TO DIVERGE IN THE EXTENDED AS THE EURO DEVELOPS AN
OMEGA BLOCK AND DIGS A CUTOFF OVER THE EAST COAST. THE GFS HAS
SIMILAR MORPHOLOGY BUT IS MUCH LESS AGGRESSIVE WITH THE TROF IN
THE EAST. WILL LEAN TOWARD A EURO SOLUTION FOR THE FORECAST.
EXPECT THE WEDGE SITUATION TO REMAIN IN PLACE THROUGH MONDAY WITH
DIURNAL TRENDS LEADING TO CHC/LKLY POPS WITH THUNDER THROUGH
MONDAY. IT LOOKS LIKE THE HIGH WILL FINALLY EDGE FAR ENOUGH TO THE
EAST LATE MONDAY TO NUDGE THE FRONT NORTH THROUGH OUR AREA AND GET
US INTO THE WARM SECTOR. BELIEVE TUESDAY WILL BE OUR BEST BET TO
AVOID PCPN WITH FRONT TO OUR NORTH AND SOME SHORT WAVE
RIDGING...THOUGH LOCAL MOUNTAIN EFFECTS MAY STILL COOK UP SOME
ISOLATED CONVECTION. NEXT FRONT WILL BE APPROACHING FROM THE WEST
ON WEDNESDAY SO EXPECT INCREASING CHC OF THUNDER AS WE GET INTO
WEDNESDAY AFTERNOON. THE FRONT WANTS TO PUSH THROUGH AND CLEAR THE
AREA FOR THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW
IT DOWN AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL
POSITION THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 800 PM EDT THURSDAY...
SCT-BKN BAND OF SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE
TO WORK ITS WAY ACROSS THE AREA EARLY THIS EVENING AND WEEKEND.
STRONGEST SFC GUSTS THAT WE HAVE OBSERVED FROM ANY OF THIS
ACTIVITY HAS BEEN ABOUT 30 KTS. RISK WILL CONTINUE FOR A FEW MORE
HOURS...THROUGH ABOUT 02Z/10PM...B4 ACTIVITY FADES TO JUST AN
AREA OF MID/UPPER LEVEL CLOUDINESS. OUTSIDE OF THE AREA OF
SHRA/TSTM ACTIVITY...CONDITIONS WERE PRIMARILY VFR. THESE VFR
CONDITIONS SHOULD PERSIST UNTIL SKIES CLEAR TOWARD MORNING. WITH
ANY CLEARING...EXPECT AREAS OF FOG...ESP AREAS WHICH RECEIVED
RAIN...SUCH AS KLWB.
DURING THE OVERNIGHT...A COLD FRONT WILL PUSH SOUTHWARD FROM
NORTHERN VIRGINIA...PASSING ACROSS LYH AND DAN...AND ADVANCING
CLOSE TO ROA. WITH THE WEAKLY STABLE AIRMASS IN PLACE...EXPECT A
LIGHT NORTHEASTERLY FLOW. ON FRIDAY...WITH DAYTIME HEATING...THE
FRONTAL BOUNDARY DRAPED ACROSS OUR AREA WILL PROVIDE THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS...BUT MAINLY DURING THE
AFTERNOON.
THE FRONT WILL LINGER ACROSS THE AREA THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...RESULTING IN A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASS ACROSS THE FRONTAL BOUNDARY...OFFERING UPPER LEVEL SUPPORT.
PERIODS OF MVFR/IFR ARE EXPECTED TO BE ASSOCIATED WITH THE
SHOWER AND THUNDERSTORM ACTIVITY. PATCHY EARLY MORNING FOG CAN
ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...MBS
LONG TERM...AMS/MBS
AVIATION...PM
000
FXUS61 KRNK 162011
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
411 PM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SINK FROM THE OHIO RIVER VALLEY
THROUGH THE EVENING...AND WILL SETTLE ACROSS THE EASTERN HALF OF
THE FORECAST AREA BY FRIDAY AFTERNOON. THE FRONT WILL REMAIN IN
THE AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY
SHOWER AND THUNDERSTORM ACTIVITY...MAINLY DURING THE AFTERNOON
AND EVENING HOURS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 400 PM EDT THURSDAY...
RADAR INDICATES A BAND OF SHOWERS AND THUNDERSTORMS ACROSS OUR
NORTHERN TIER OF COUNTIES THIS AFTERNOON...A FEW OF WHICH HAVE
BECOME STRONG TO BORDERLINE SEVERE. EXPECT THESE SHOWERS AND
THUNDERSTORMS TO SINK SOUTH ACROSS THE AREA THROUGH THE
EVENING...BUT TO WEAKEN AFTER SUNSET WITH THE LOSS OF DAYTIME
HEATING. TOWARD SUNSET...BELIEVE WESTERLY WINDS WILL DIMINISH IN
SPEED...WHICH WILL ERODE THE CAP OVERHEAD AND ALLOW A FEW MORE
SHOWERS/THUNDERSTORMS TO DEVELOP FURTHER SOUTH ACROSS THE
AREA...BUT THIS ACTIVITY SHOULD REMAIN SHORTLIVED. BY
MIDNIGHT...EXPECT ONLY LINGERING SHOWER ACTIVITY MAINLY NORTH OF
THE HIGHWAY 460 CORRIDOR.
CLOUD COVER WILL REMAIN WIDESPREAD THROUGH THE NIGHT...AND WITH
MOISTURE/WARM AIR CONVERGENCE AHEAD OF THE FRONT...WILL BE LOOKING
AT A WARM/MUGGY NIGHT WITH TEMPERATURES MAINLY UPPER 50S TO LOWER
60S. MODELS PROG THE COLD FRONT SINKING SOUTHWARD...EAST OF THE
BLUE RIDGE...BY LATE FRIDAY MORNING...BRINGING A LIGHT NORTHEASTERLY
WINDFLOW ACROSS THE AREA. MAY SEE PATCHY FOG DEVELOP IN THE MORE
STABLE AIRMASS ACROSS THE PIEDMONTS...WHICH WILL BURN OFF SHORTLY
AFTER SUNRISE.
SHOWER ACTIVITY WILL BE MORE WIDESPREAD DURING THE AFTERNOON AND
EVENING WITH THE FRONT SITUATED ACROSS THE AREA. INCREASED CLOUD
COVER WILL ALSO LIMIT AFTERNOON HEATING...KEEPING HIGHS CONFINED
TO THE UPPER 70S WEST AND THE LOW 80S EAST.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 300 PM EDT THURSDAY...
A RATHER OBNOXIOUS PATTERN SHAPING UP THROUGH THE FORECAST
PERIOD. UPPER TROF OVER THE MID WEST WILL BE OPENING UP AS BITS OF
ENERGY GET EJECTED TOWARD US. DIFFUSE FRONTAL BOUNDARY AT THE SFC
WILL ALSO BE WAFFLING BACK AND FORTH WITH NO BIG KICKER TO PUSH IT
CLEAR WHILE HIGH PRESSURE BEGINS TO WEDGE DOWN THE ERN SEABOARD.
EXPECT CONVECTION THAT FIRES TOMORROW WILL LINGER INTO THE
EVENING BEFORE GRADUALLY DIMINISHING OVERNIGHT AS HIGH PRESSURE
WEDGES DOWN THE EAST COAST. EXPECTING ENHANCED POPS ALONG THE BLUE
RIDGE AS E/SELY FLOW SETS UP. AFTER A BRIEF LULL EARLY SATURDAY
MORNING...EXPECT MORE CONVECTION TO DEVELOP WITH DIFFUSE FRONT IN
THE AREA AND WEAK LOW PRESSURE APPROACHING FROM THE WEST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MODELS BEGIN TO DIVERGE IN THE EXTENDED AS THE EURO DEVELOPS AN
OMEGA BLOCK AND DIGS A CUTOFF OVER THE EAST COAST. THE GFS HAS
SIMILAR MORPHOLOGY BUT IS MUCH LESS AGGRESSIVE WITH THE TROF IN
THE EAST. WILL LEAN TOWARD A EURO SOLUTION FOR THE FORECAST.
EXPECT THE WEDGE SITUATION TO REMAIN IN PLACE THROUGH MONDAY WITH
DIURNAL TRENDS LEADING TO CHC/LKLY POPS WITH THUNDER THROUGH
MONDAY. IT LOOKS LIKE THE HIGH WILL FINALLY EDGE FAR ENOUGH TO THE
EAST LATE MONDAY TO NUDGE THE FRONT NORTH THROUGH OUR AREA AND GET
US INTO THE WARM SECTOR. BELIEVE TUESDAY WILL BE OUR BEST BET TO
AVOID PCPN WITH FRONT TO OUR NORTH AND SOME SHORT WAVE
RIDGING...THOUGH LOCAL MOUNTAIN EFFECTS MAY STILL COOK UP SOME
ISOLATED CONVECTION. NEXT FRONT WILL BE APPROACHING FROM THE WEST
ON WEDNESDAY SO EXPECT INCREASING CHC OF THUNDER AS WE GET INTO
WEDNESDAY AFTERNOON. THE FRONT WANTS TO PUSH THROUGH AND CLEAR THE
AREA FOR THURSDAY...THOUGH WAVE DEVELOPMENT ON THE FRONT MAY SLOW
IT DOWN AND DO NOT HAVE A GREAT DEAL OF CONFIDENCE WITH FRONTAL
POSITION THIS FAR OUT WITH MODELS STILL SORTING THINGS OUT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 200 PM EDT THURSDAY...
CONDITIONS STILL VFR THIS AFTERNOON...ALTHOUGH CLOUDS CONTINUE TO
LOWER AS A COLD FRONT AND ASSOCIATED CONVECTION SINKS IN FROM THE
NORTH. BEST CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY THIS
EVENING WILL BE AT LWB...WITH SLIGHT CHANCE FOR BLF...BCB...ROA
AND LYH. STILL LOOKING FOR WESTERLY DOWNSLOPE WINDFLOW TO KEEP
CONVECTION CAPPED THROUGH SUNSET UNTIL WINDS DIE DOWN...AT WHICH
POINT EXPECT TO SEE SHOWERS AND A FEW THUNDERSTORMS BECOME MORE
SPREAD ACROSS THE FORECAST AREA. THAT SAID...CONVECTION SHOULD BE
SHORTLIVED WITH THE LOSS OF DAYTIME HEATING...WITH ONLY SPOTTY
SHOWER ACTIVITY LINGERING AFTER MIDNIGHT. ANY LOCATIONS WHERE
THUNDERSTORM ACTIVITY DOES PASS CAN EXPECT BRIEF PERIODS OF
IFR CONDITIONS...WITH VISIBILITIES DROPPING TO 1/4SM OR LESS IN
HEAVY RAIN.
OVERNIGHT...THE COLD FRONT WILL PUSH SOUTHWARD EAST OF THE BLUE
RIDGE...PASSING ACROSS LYH AND DAN...AND ADVANCING CLOSE TO ROA.
WITH THE WEAKLY STABLE AIRMASS IN PLACE...EXPECT A LIGHT
NORTHEASTERLY FLOW...WITH PATCHY FOG DEVELOPING ACROSS THE AREA.
WITH DAYTIME HEATING...THE FRONTAL BOUNDARY DRAPED ACROSS OUR AREA
WILL PROVIDE THE FOCUS FOR SCATTERED SHOWERS DURING THE
MORNING...WITH SOME INTENSIFYING INTO THUNDERSTORMS BY EARLY
AFTERNOON. MAIN AREAS TO WATCH WILL BE WHERE SUNSHINE BREAKS DOWN
TO THE SURFACE. WHILE SKIES WILL BE MOSTLY CLOUDY TO START THE
DAY...EXPECT TO SEE A FEW LOCATIONS BREAK OUT DURING THE
MORNING...ALLOWING SURFACE TEMPERATURES TO SPIKE UP QUICKLY.
THE FRONT WILL LINGER ACROSS THE AREA INTO EARLY NEXT WEEK...
RESULTING IN A PERSISTENT PATTERN OF SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES PASS
ACROSS...OFFERING UPPER LEVEL SUPPORT. PERIODS OF MVFR/IFR ARE
EXPECTED DURING ANY SHOWERS AND THUNDERSTORMS. PATCHY EARLY
MORNING FOG CAN ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...MBS
LONG TERM...AMS/MBS
AVIATION...JH/NF
000
FXUS61 KRNK 161824
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
224 PM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT IN THE OHIO VALLEY WILL DRIFT SLOWLY SOUTH ACROSS THE
MID ATLANTIC REGION TODAY BEFORE REACHING THE BLUE RIDGE FRIDAY
INTO FRIDAY NIGHT. THIS FRONT WILL REMAIN IN THE AREA THROUGH THE
WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 252 AM EDT THURSDAY...
LOOKING AT SCATTERED MID AND HIGH CLOUDS MAKING THEIR WAY ACROSS
THE AREA THIS MORNING...WHILE SHOWER AND THUNDERSTORM ACTIVITY
ASSOCIATED WITH AN APPROACHING COLD FRONT CONTINUES TO PUSH SOUTH
FROM NEAR THE OHIO RIVER VALLEY. MAY SEE A FEW SPRINKLES REACH
INTO BATH...ROCKBRIDGE AND PERHAPS BUCKINGHAM COUNTIES THIS
MORNING AS A WAVE PASSES ALONG THE FRONT...BUT THE VAST MAJORITY
OF RAIN IS EXPECTED TO STAY TO THE NORTH THROUGH MID AFTERNOON PER
LATEST SET OF MODELS. EVEN AS CONVECTION ENTERS THE AREA...EXPECT
THE RAINFALL TO BE A LITTLE MORE ON THE SPOTTY SIDE AS DEEP
WESTERLY FLOW KEEPS THE MID LEVELS OF THE ATMOSPHERE DRY TO START.
THEREFORE ADJUSTED RAIN CHANCES IN THE FORECAST TO REFLECT THIS
THINKING. AT ANY RATE...HIGH CLOUDS ARE THIN ENOUGH TO ALLOW
ABUNDANT SUNSHINE TO REACH THE SURFACE ACROSS THE PIEDMONTS...WITH
TEMPERATURES ALREADY NEAR 80 DEGREES AND CLIMBING. CLOUD COVER IS
THICKER ACROSS THE MOUNTAINS...AND CURRENTLY OBSERVING UPPER 60S
TO MID 70S.
BETTER CONVECTIVE COVERAGE WILL COME SHORTLY BEFORE SUNSET ONCE
MIXING DECREASES...ALLOWING MORE CONVERGENCE TO DEVELOP AS
DEWPOINTS RISE. MAIN FOCUS WOULD AGAIN BE OVER THE NORTHWEST AND
FAR EAST...CLOSER TO THE FRONT...WITH MORE WIDELY SCATTERED
COVERAGE ELSEWHERE AS SUGGESTED BY THE RATHER WET LOCAL RNK-WRF
SOLUTION. INSTABILITY APPEARS TO QUICKLY WANE AFTER MIDNIGHT AS
THE WEAK UPPER IMPULSE EXITS...SO DECREASING RAIN CHANCES TO MORE
ISOLATED COVERAGE LATE TONIGHT. SHOULD BE A WARM/MUGGY NIGHT WITH
SOME PATCHY FOG AROUND AND TEMPERATURES MAINLY UPPER 50S TO LOWER
60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT THURSDAY...
UNSETTLED WEATHER EXPECTED ALONG AND SOUTH OF A FRONTAL BOUNDARY
WHICH DROPS SOUTH ACROSS THE MID ATLANTIC REGION THROUGH SATURDAY
NIGHT. THIS FRONT ENTERS NORTHERN PORTIONS OF OUR AREA FRIDAY AND
PUSHES TO THE VIRGINIA/NORTH CAROLINA BORDER ON SATURDAY.
CUT BACK POPS INITIALLY FRIDAY MORNING USING A BLEND OF THE GFS/NAM
WITH SCATTERED CONVECTION MAINLY IN THE WEST WITH LIGHTER CHANCES IN
THE EAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS
THE ENTIRE REGION FRIDAY AFTERNOON INTO FRIDAY EVENING. MLCAPE
VALUES ON FRIDAY MAY CLIMB TO 500 TO 1000 J/KG...WITH 0-6KM SHEAR
WEAK AROUND 20 KTS. LOWERED HIGHS A FEW DEGREES FRIDAY WITH VALUES
FROM THE LOWER 70S IN THE WEST TO THE LOWER 80S IN THE EAST. ALLOWED
FOR SOME SHOWERS WITH SHORTWAVE MAINLY ACROSS THE NORTH FRIDAY
NIGHT. FRIDAY NIGHT WILL BE MILD WITH READINGS FROM THE LOWER 50S IN
THE MOUNTAINS TO THE LOWER 60S IN THE EAST. INCREASED POPS TO LIKELY
ON SATURDAY WITH NAM...GFS AND ECMWF ALL SUPPORTING THUNDERSTORMS.
ROBUST CAPES OFF THE GFS FROM 1 TO 3K J/KG LEAD TO POTENTIAL FOR
STRONGER STORMS IN SOUTHSIDE. A PULSE TYPE SEVERE STORM MAY BE
POSSIBLE WITH WIND AND RAIN. TRAINING OF ECHOES COULD RESULT IN
FLOODING PROBLEMS WITH HIGHER PWAT VALUES. WENT WITH COOLER HIGHS
FOR SATURDAY IN THE 70S WITH BETTER COVERAGE AND THICK CLOUDS. HELD
ON TO CHANCE OF SHOWERS SATURDAY NIGHT...WITH LOWS FROM THE MID 50S
IN THE MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SUNDAY...BIT WITH A
SHORT WAVE OVER THE SOUTHERN APPALACHIANS. MODELS DIFFER IN THE
SURFACE REFLECTION OF THE SOUTHERN WAVE. MAIN FRONT WILL BE TO THE
NORTH OF THE FORECAST AREA BUT INFLUENCE OF THE SOUTHERN
APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN BETTER AREAL
COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 200 PM EDT THURSDAY...
CONDITIONS STILL VFR THIS AFTERNOON...ALTHOUGH CLOUDS CONTINUE TO
LOWER AS A COLD FRONT AND ASSOCIATED CONVECTION SINKS IN FROM THE
NORTH. BEST CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY THIS
EVENING WILL BE AT LWB...WITH SLIGHT CHANCE FOR BLF...BCB...ROA
AND LYH. STILL LOOKING FOR WESTERLY DOWNSLOPE WINDFLOW TO KEEP
CONVECTION CAPPED THROUGH SUNSET UNTIL WINDS DIE DOWN...AT WHICH
POINT EXPECT TO SEE SHOWERS AND A FEW THUNDERSTORMS BECOME MORE
SPREAD ACROSS THE FORECAST AREA. THAT SAID...CONVECTION SHOULD BE
SHORTLIVED WITH THE LOSS OF DAYTIME HEATING...WITH ONLY SPOTTY
SHOWER ACTIVITY LINGERING AFTER MIDNIGHT. ANY LOCATIONS WHERE
THUNDERSTORM ACTIVITY DOES PASS CAN EXPECT BRIEF PERIODS OF
IFR CONDITIONS...WITH VISIBILITIES DROPPING TO 1/4SM OR LESS IN
HEAVY RAIN.
OVERNIGHT...THE COLD FRONT WILL PUSH SOUTHWARD EAST OF THE BLUE
RIDGE...PASSING ACROSS LYH AND DAN...AND ADVANCING CLOSE TO ROA.
WITH THE WEAKLY STABLE AIRMASS IN PLACE...EXPECT A LIGHT
NORTHEASTERLY FLOW...WITH PATCHY FOG DEVELOPING ACROSS THE AREA.
WITH DAYTIME HEATING...THE FRONTAL BOUNDARY DRAPED ACROSS OUR AREA
WILL PROVIDE THE FOCUS FOR SCATTERED SHOWERS DURING THE
MORNING...WITH SOME INTENSIFYING INTO THUNDERSTORMS BY EARLY
AFTERNOON. MAIN AREAS TO WATCH WILL BE WHERE SUNSHINE BREAKS DOWN
TO THE SURFACE. WHILE SKIES WILL BE MOSTLY CLOUDY TO START THE
DAY...EXPECT TO SEE A FEW LOCATIONS BREAK OUT DURING THE
MORNING...ALLOWING SURFACE TEMPERATURES TO SPIKE UP QUICKLY.
THE FRONT WILL LINGER ACROSS THE AREA INTO EARLY NEXT WEEK...
RESULTING IN A PERSISTENT PATTERN OF SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES PASS
ACROSS...OFFERING UPPER LEVEL SUPPORT. PERIODS OF MVFR/IFR ARE
EXPECTED DURING ANY SHOWERS AND THUNDERSTORMS. PATCHY EARLY
MORNING FOG CAN ALSO BE EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF
000
FXUS61 KRNK 161434
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1034 AM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT IN THE OHIO VALLEY WILL DRIFT SLOWLY SOUTH ACROSS THE
MID ATLANTIC REGION TODAY BEFORE REACHING THE BLUE RIDGE FRIDAY
INTO FRIDAY NIGHT. THIS FRONT WILL REMAIN IN THE AREA THROUGH THE
WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 252 AM EDT THURSDAY...
LOOKING AT SCATTERED MID AND HIGH CLOUDS MAKING THEIR WAY ACROSS
THE AREA THIS MORNING...WHILE SHOWER AND THUNDERSTORM ACTIVITY
ASSOCIATED WITH AN APPROACHING COLD FRONT CONTINUES TO PUSH SOUTH
FROM NEAR THE OHIO RIVER VALLEY. MAY SEE A FEW SPRINKLES REACH
INTO BATH...ROCKBRIDGE AND PERHAPS BUCKINGHAM COUNTIES THIS
MORNING AS A WAVE PASSES ALONG THE FRONT...BUT THE VAST MAJORITY
OF RAIN IS EXPECTED TO STAY TO THE NORTH THROUGH MID AFTERNOON PER
LATEST SET OF MODELS. EVEN AS CONVECTION ENTERS THE AREA...EXPECT
THE RAINFALL TO BE A LITTLE MORE ON THE SPOTTY SIDE AS DEEP
WESTERLY FLOW KEEPS THE MID LEVELS OF THE ATMOSPHERE DRY TO START.
THEREFORE ADJUSTED RAIN CHANCES IN THE FORECAST TO REFLECT THIS
THINKING. AT ANY RATE...HIGH CLOUDS ARE THIN ENOUGH TO ALLOW
ABUNDANT SUNSHINE TO REACH THE SURFACE ACROSS THE PIEDMONTS...WITH
TEMPERATURES ALREADY NEAR 80 DEGREES AND CLIMBING. CLOUD COVER IS
THICKER ACROSS THE MOUNTAINS...AND CURRENTLY OBSERVING UPPER 60S
TO MID 70S.
BETTER CONVECTIVE COVERAGE WILL COME SHORTLY BEFORE SUNSET ONCE
MIXING DECREASES...ALLOWING MORE CONVERGENCE TO DEVELOP AS
DEWPOINTS RISE. MAIN FOCUS WOULD AGAIN BE OVER THE NORTHWEST AND
FAR EAST...CLOSER TO THE FRONT...WITH MORE WIDELY SCATTERED
COVERAGE ELSEWHERE AS SUGGESTED BY THE RATHER WET LOCAL RNK-WRF
SOLUTION. INSTABILITY APPEARS TO QUICKLY WANE AFTER MIDNIGHT AS
THE WEAK UPPER IMPULSE EXITS...SO DECREASING RAIN CHANCES TO MORE
ISOLATED COVERAGE LATE TONIGHT. SHOULD BE A WARM/MUGGY NIGHT WITH
SOME PATCHY FOG AROUND AND TEMPERATURES MAINLY UPPER 50S TO LOWER
60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT THURSDAY...
UNSETTLED WEATHER EXPECTED ALONG AND SOUTH OF A FRONTAL BOUNDARY
WHICH DROPS SOUTH ACROSS THE MID ATLANTIC REGION THROUGH SATURDAY
NIGHT. THIS FRONT ENTERS NORTHERN PORTIONS OF OUR AREA FRIDAY AND
PUSHES TO THE VIRGINIA/NORTH CAROLINA BORDER ON SATURDAY.
CUT BACK POPS INITIALLY FRIDAY MORNING USING A BLEND OF THE GFS/NAM
WITH SCATTERED CONVECTION MAINLY IN THE WEST WITH LIGHTER CHANCES IN
THE EAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS
THE ENTIRE REGION FRIDAY AFTERNOON INTO FRIDAY EVENING. MLCAPE
VALUES ON FRIDAY MAY CLIMB TO 500 TO 1000 J/KG...WITH 0-6KM SHEAR
WEAK AROUND 20 KTS. LOWERED HIGHS A FEW DEGREES FRIDAY WITH VALUES
FROM THE LOWER 70S IN THE WEST TO THE LOWER 80S IN THE EAST. ALLOWED
FOR SOME SHOWERS WITH SHORTWAVE MAINLY ACROSS THE NORTH FRIDAY
NIGHT. FRIDAY NIGHT WILL BE MILD WITH READINGS FROM THE LOWER 50S IN
THE MOUNTAINS TO THE LOWER 60S IN THE EAST. INCREASED POPS TO LIKELY
ON SATURDAY WITH NAM...GFS AND ECMWF ALL SUPPORTING THUNDERSTORMS.
ROBUST CAPES OFF THE GFS FROM 1 TO 3K J/KG LEAD TO POTENTIAL FOR
STRONGER STORMS IN SOUTHSIDE. A PULSE TYPE SEVERE STORM MAY BE
POSSIBLE WITH WIND AND RAIN. TRAINING OF ECHOES COULD RESULT IN
FLOODING PROBLEMS WITH HIGHER PWAT VALUES. WENT WITH COOLER HIGHS
FOR SATURDAY IN THE 70S WITH BETTER COVERAGE AND THICK CLOUDS. HELD
ON TO CHANCE OF SHOWERS SATURDAY NIGHT...WITH LOWS FROM THE MID 50S
IN THE MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SUNDAY...BIT WITH A
SHORT WAVE OVER THE SOUTHERN APPALACHIANS. MODELS DIFFER IN THE
SURFACE REFLECTION OF THE SOUTHERN WAVE. MAIN FRONT WILL BE TO THE
NORTH OF THE FORECAST AREA BUT INFLUENCE OF THE SOUTHERN
APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN BETTER AREAL
COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 655 AM EDT THURSDAY...
VFR CONDITIONS WILL CONTINUE TO PREVAIL INTO THIS AFTERNOON WITH
PERIODIC PASSING MID AND HIGH CLOUDS ESPCLY THIS MORNING. MAY SEE
SOME LOWER STRATO-CU CLIP KLWB THIS MORNING ASSOCIATED WITH
CONVECTION TO THE NORTH BUT STILL APPEARS ABOVE MVFR LEVELS FOR
NOW. WEST WINDS WILL AGAIN BECOME STRONG ESPCLY ALONG THE RIDGES
THIS AFTERNOON WITH GUSTS TO 15-25 KTS.
OTRW EXPECTING A BROAD AREA OF SCTD/BKN CI/AC TO INIT
THIS MORNING...THEN MORE CU AS HEATING DEVELOPS AHEAD OF A COLD
FRONT SAGGING IN FROM THE NORTH. THIS BOUNDARY SHOULD ALSO ACT TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS BY MID AFTERNOON AND
EVENING. AT THIS POINT APPEARS LOCATIONS ACROSS SE WVA...NAMELY
KLWB...AND OUT EAST AROUND KLYH HAVE THE BEST SHOT AT SEEING A
BAND OF LATE DAY SHRA/TSRA. THUS INCLUDED A VCTS/CB MENTION AT
THESE LOCATIONS AFTER 21Z/5PM AND A PREVAILING -SHRA MENTION AT
KLWB DURING THE EARLY EVENING. ELSW LOW CONFIDENCE IN SEEING TSRA
GIVEN DEEP WESTERLY FLOW BUT IF CONVECTION CAN ORGANIZE INTO MORE
OF A LINE FEATURE TO THE NORTH THEN ISOLATED -TSRA COULD AFFECT
MUCH OF THE REGION ESPCLY AFTER 00Z/8PM. OTRW APPEARS ANY AREAS OF
MVFR IN SHRA/TSRA SHOULD END LATE THURSDAY EVENING WITH MAINLY VFR
CIGS AND SOME LATE NIGHT MVFR/IFR VSBYS IN FOG PENDING LOCATIONS
OF EARLIER RAINFALL.
FRIDAY INTO EARLY NEXT WEEK WILL BE A PERSISTENT PATTERN OF
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK
IMPULSES PASSING ALOFT WILL OFFER UPPER LEVEL SUPPORT. PERIODS OF
MVFR/IFR ARE POSSIBLE DURING ANY TIMES OF SHOWERS AND
THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KK
LONG TERM...AMS
AVIATION...CF/JH
000
FXUS61 KRNK 161122
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
722 AM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT IN THE OHIO VALLEY WILL DRIFT SLOWLY SOUTH ACROSS THE
MID ATLANTIC REGION TODAY BEFORE REACHING THE BLUE RIDGE FRIDAY
INTO FRIDAY NIGHT. THIS FRONT WILL REMAIN IN THE AREA THROUGH THE
WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 252 AM EDT THURSDAY...
MAIN CONCERN WITH CONVECTIVE CHANCES TODAY AS THE COLD FRONT TO THE
NORTH SAGS SOUTH TOWARD NRN VA BY THIS EVENING AND TO JUST EAST OF
THE BLUE RIDGE LATE TONIGHT. MODELS SHOWING QUITE A BIT OF DEBRIS
CLOUDS OVER THE AREA THIS MORNING IN ADVANCE OF THE BAND OF
CONVECTION NOW ALONG THE BOUNDARY IN THE OHIO VALLEY BEFORE MIXING
THINGS OUT TO SOME DEGREE THIS AFTERNOON. DEEP WESTERLY FLOW AHEAD
OF THE FRONT COMBINED WITH A WEAK IMPULSE SHEARING EAST FROM THE
UPPER SYSTEM TO THE SW LIKELY TO SLOW THE SRN PROGRESS DOWN A BIT.
HOWEVER PWATS LOOK TO INCREASE LATER THIS AFTERNOON UNDER ONLY A
WEAK RESIDUAL CAP AND MORE OF AN INVERTED V SOUNDING PROVIDED ENOUGH
HEATING TAKES SHAPE. APPEARS SOME SORT OF DIFF HEATING BOUNDARY FROM
EARLY MORNING LEFTOVER CLOUDS TO THE NORTH MAY ACT TO FIRE MORE
BANDS OF TSRA ESPCLY NW LATER ON PER WESTERLY CONVERGENCE...AND
PERHAPS ACROSS THE NORTH/NE SECTIONS GIVEN BETTER INSTABILITY IF CAN
OVERCOME DOWNSLOPING. THIS MORE IN LINE WITH THE LATEST SPC WRF AND
HIRES ARW WHICH TEND TO SPLIT PRECIP BETWEEN THESE AREAS WHERE JUST
TOO MUCH WEST WIND UNTIL THIS EVENING. THUS HAVE SLOWED POPS DOWN
SOME UNTIL LATE MORNING/EARLY AFTERNOON NORTH...AND LIMITED CHANCES
NEW RIVER VALLEY...AND JUST OFF THE BLUE RIDGE WITH LOW LIKELYS FAR
NORTH/NW...AND MAINLY CHANCE TO SLIGHTS ELSW. DECENT PROGGED DCAPE
AND UNIDIRECTIONAL WESTERLY FLOW SUPPORTIVE OF SOME WIND THREAT FROM
NORTH TO SOUTH IF A BROKEN LINE CAN ORGANIZE SO WILL MENTION WIND
POTENTIAL IN THE HWO IN SPOTS. WARM START AND WEST WIND COMPRESSION
SHOULD AGAIN ALLOW THE PIEDMONT TO PUSH 90 PROVIDED ENOUGH
INSOLATION WITH 80S ELSW EXCEPT 70S EXTREME WEST-NW FOR HIGHS.
BETTER CONVECTIVE COVERAGE MAY COME DURING THE EARLY EVENING ONCE
MIXING DECREASES ALLOWING MORE CONVERGENCE TO DEVELOP AS DEWPOINTS
RISE. MAIN FOCUS WOULD AGAIN BE OVER THE NW AND FAR EAST CLOSER TO
THE FRONT WITH MORE SCATTERED NATURE COVERAGE ELSW AS SUGGESTED BY
THE RATHER WET LOCAL RNK-WRF SOLUTION WHICH LOOKS OVERDONE.
INSTABILITY APPEARS TO QUICKLY WANE AFTER MIDNIGHT AS THE WEAK
UPPER IMPULSE EXITS SO DECREASING POPS TO MORE ISOLATED COVERAGE
LATE AFTER MAINLY CHANCE COVERAGE DURING THE EVENING. SHOULD BE A
WARM/MUGGY NIGHT WITH SOME PATCHY FOG AROUND AND TEMPS MAINLY
UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT THURSDAY...
UNSETTLED WEATHER EXPECTED ALONG AND SOUTH OF A FRONTAL BOUNDARY
WHICH DROPS SOUTH ACROSS THE MID ATLANTIC REGION THROUGH SATURDAY
NIGHT. THIS FRONT ENTERS NORTHERN PORTIONS OF OUR AREA FRIDAY AND
PUSHES TO THE VIRGINIA/NORTH CAROLINA BORDER ON SATURDAY.
CUT BACK POPS INITIALLY FRIDAY MORNING USING A BLEND OF THE GFS/NAM
WITH SCATTERED CONVECTION MAINLY IN THE WEST WITH LIGHTER CHANCES IN
THE EAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS
THE ENTIRE REGION FRIDAY AFTERNOON INTO FRIDAY EVENING. MLCAPE
VALUES ON FRIDAY MAY CLIMB TO 500 TO 1000 J/KG...WITH 0-6KM SHEAR
WEAK AROUND 20 KTS. LOWERED HIGHS A FEW DEGREES FRIDAY WITH VALUES
FROM THE LOWER 70S IN THE WEST TO THE LOWER 80S IN THE EAST. ALLOWED
FOR SOME SHOWERS WITH SHORTWAVE MAINLY ACROSS THE NORTH FRIDAY
NIGHT. FRIDAY NIGHT WILL BE MILD WITH READINGS FROM THE LOWER 50S IN
THE MOUNTAINS TO THE LOWER 60S IN THE EAST. INCREASED POPS TO LIKELY
ON SATURDAY WITH NAM...GFS AND ECMWF ALL SUPPORTING THUNDERSTORMS.
ROBUST CAPES OFF THE GFS FROM 1 TO 3K J/KG LEAD TO POTENTIAL FOR
STRONGER STORMS IN SOUTHSIDE. A PULSE TYPE SEVERE STORM MAY BE
POSSIBLE WITH WIND AND RAIN. TRAINING OF ECHOES COULD RESULT IN
FLOODING PROBLEMS WITH HIGHER PWAT VALUES. WENT WITH COOLER HIGHS
FOR SATURDAY IN THE 70S WITH BETTER COVERAGE AND THICK CLOUDS. HELD
ON TO CHANCE OF SHOWERS SATURDAY NIGHT...WITH LOWS FROM THE MID 50S
IN THE MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SUNDAY...BIT WITH A
SHORT WAVE OVER THE SOUTHERN APPALACHIANS. MODELS DIFFER IN THE
SURFACE REFLECTION OF THE SOUTHERN WAVE. MAIN FRONT WILL BE TO THE
NORTH OF THE FORECAST AREA BUT INFLUENCE OF THE SOUTHERN
APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN BETTER AREAL
COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 655 AM EDT THURSDAY...
VFR CONDITIONS WILL CONTINUE TO PREVAIL INTO THIS AFTERNOON WITH
PERIODIC PASSING MID AND HIGH CLOUDS ESPCLY THIS MORNING. MAY SEE
SOME LOWER STRATO-CU CLIP KLWB THIS MORNING ASSOCIATED WITH
CONVECTION TO THE NORTH BUT STILL APPEARS ABOVE MVFR LEVELS FOR
NOW. WEST WINDS WILL AGAIN BECOME STRONG ESPCLY ALONG THE RIDGES
THIS AFTERNOON WITH GUSTS TO 15-25 KTS.
OTRW EXPECTING A BROAD AREA OF SCTD/BKN CI/AC TO INIT
THIS MORNING...THEN MORE CU AS HEATING DEVELOPS AHEAD OF A COLD
FRONT SAGGING IN FROM THE NORTH. THIS BOUNDARY SHOULD ALSO ACT TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS BY MID AFTERNOON AND
EVENING. AT THIS POINT APPEARS LOCATIONS ACROSS SE WVA...NAMELY
KLWB...AND OUT EAST AROUND KLYH HAVE THE BEST SHOT AT SEEING A
BAND OF LATE DAY SHRA/TSRA. THUS INCLUDED A VCTS/CB MENTION AT
THESE LOCATIONS AFTER 21Z/5PM AND A PREVAILING -SHRA MENTION AT
KLWB DURING THE EARLY EVENING. ELSW LOW CONFIDENCE IN SEEING TSRA
GIVEN DEEP WESTERLY FLOW BUT IF CONVECTION CAN ORGANIZE INTO MORE
OF A LINE FEATURE TO THE NORTH THEN ISOLATED -TSRA COULD AFFECT
MUCH OF THE REGION ESPCLY AFTER 00Z/8PM. OTRW APPEARS ANY AREAS OF
MVFR IN SHRA/TSRA SHOULD END LATE THURSDAY EVENING WITH MAINLY VFR
CIGS AND SOME LATE NIGHT MVFR/IFR VSBYS IN FOG PENDING LOCATIONS
OF EARLIER RAINFALL.
FRIDAY INTO EARLY NEXT WEEK WILL BE A PERSISTENT PATTERN OF
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK
IMPULSES PASSING ALOFT WILL OFFER UPPER LEVEL SUPPORT. PERIODS OF
MVFR/IFR ARE POSSIBLE DURING ANY TIMES OF SHOWERS AND
THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...AMS
AVIATION...CF/JH
000
FXUS61 KRNK 160736
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
336 AM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT IN THE OHIO VALLEY WILL DRIFT SLOWLY SOUTH ACROSS THE
MID ATLANTIC REGION TODAY BEFORE REACHING THE BLUE RIDGE FRIDAY
INTO FRIDAY NIGHT. THIS FRONT WILL REMAIN IN THE AREA THROUGH THE
WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 252 AM EDT THURSDAY...
MAIN CONCERN WITH CONVECTIVE CHANCES TODAY AS THE COLD FRONT TO THE
NORTH SAGS SOUTH TOWARD NRN VA BY THIS EVENING AND TO JUST EAST OF
THE BLUE RIDGE LATE TONIGHT. MODELS SHOWING QUITE A BIT OF DEBRIS
CLOUDS OVER THE AREA THIS MORNING IN ADVANCE OF THE BAND OF
CONVECTION NOW ALONG THE BOUNDARY IN THE OHIO VALLEY BEFORE MIXING
THINGS OUT TO SOME DEGREE THIS AFTERNOON. DEEP WESTERLY FLOW AHEAD
OF THE FRONT COMBINED WITH A WEAK IMPULSE SHEARING EAST FROM THE
UPPER SYSTEM TO THE SW LIKELY TO SLOW THE SRN PROGRESS DOWN A BIT.
HOWEVER PWATS LOOK TO INCREASE LATER THIS AFTERNOON UNDER ONLY A
WEAK RESIDUAL CAP AND MORE OF AN INVERTED V SOUNDING PROVIDED ENOUGH
HEATING TAKES SHAPE. APPEARS SOME SORT OF DIFF HEATING BOUNDARY FROM
EARLY MORNING LEFTOVER CLOUDS TO THE NORTH MAY ACT TO FIRE MORE
BANDS OF TSRA ESPCLY NW LATER ON PER WESTERLY CONVERGENCE...AND
PERHAPS ACROSS THE NORTH/NE SECTIONS GIVEN BETTER INSTABILITY IF CAN
OVERCOME DOWNSLOPING. THIS MORE IN LINE WITH THE LATEST SPC WRF AND
HIRES ARW WHICH TEND TO SPLIT PRECIP BETWEEN THESE AREAS WHERE JUST
TOO MUCH WEST WIND UNTIL THIS EVENING. THUS HAVE SLOWED POPS DOWN
SOME UNTIL LATE MORNING/EARLY AFTERNOON NORTH...AND LIMITED CHANCES
NEW RIVER VALLEY...AND JUST OFF THE BLUE RIDGE WITH LOW LIKELYS FAR
NORTH/NW...AND MAINLY CHANCE TO SLIGHTS ELSW. DECENT PROGGED DCAPE
AND UNIDIRECTIONAL WESTERLY FLOW SUPPORTIVE OF SOME WIND THREAT FROM
NORTH TO SOUTH IF A BROKEN LINE CAN ORGANIZE SO WILL MENTION WIND
POTENTIAL IN THE HWO IN SPOTS. WARM START AND WEST WIND COMPRESSION
SHOULD AGAIN ALLOW THE PIEDMONT TO PUSH 90 PROVIDED ENOUGH
INSOLATION WITH 80S ELSW EXCEPT 70S EXTREME WEST-NW FOR HIGHS.
BETTER CONVECTIVE COVERAGE MAY COME DURING THE EARLY EVENING ONCE
MIXING DECREASES ALLOWING MORE CONVERGENCE TO DEVELOP AS DEWPOINTS
RISE. MAIN FOCUS WOULD AGAIN BE OVER THE NW AND FAR EAST CLOSER TO
THE FRONT WITH MORE SCATTERED NATURE COVERAGE ELSW AS SUGGESTED BY
THE RATHER WET LOCAL RNK-WRF SOLUTION WHICH LOOKS OVERDONE.
INSTABILITY APPEARS TO QUICKLY WANE AFTER MIDNIGHT AS THE WEAK
UPPER IMPULSE EXITS SO DECREASING POPS TO MORE ISOLATED COVERAGE
LATE AFTER MAINLY CHANCE COVERAGE DURING THE EVENING. SHOULD BE A
WARM/MUGGY NIGHT WITH SOME PATCHY FOG AROUND AND TEMPS MAINLY
UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT THURSDAY...
UNSETTLED WEATHER EXPECTED ALONG AND SOUTH OF A FRONTAL BOUNDARY
WHICH DROPS SOUTH ACROSS THE MID ATLANTIC REGION THROUGH SATURDAY
NIGHT. THIS FRONT ENTERS NORTHERN PORTIONS OF OUR AREA FRIDAY AND
PUSHES TO THE VIRGINIA/NORTH CAROLINA BORDER ON SATURDAY.
CUT BACK POPS INITIALLY FRIDAY MORNING USING A BLEND OF THE GFS/NAM
WITH SCATTERED CONVECTION MAINLY IN THE WEST WITH LIGHTER CHANCES IN
THE EAST. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS
THE ENTIRE REGION FRIDAY AFTERNOON INTO FRIDAY EVENING. MLCAPE
VALUES ON FRIDAY MAY CLIMB TO 500 TO 1000 J/KG...WITH 0-6KM SHEAR
WEAK AROUND 20 KTS. LOWERED HIGHS A FEW DEGREES FRIDAY WITH VALUES
FROM THE LOWER 70S IN THE WEST TO THE LOWER 80S IN THE EAST. ALLOWED
FOR SOME SHOWERS WITH SHORTWAVE MAINLY ACROSS THE NORTH FRIDAY
NIGHT. FRIDAY NIGHT WILL BE MILD WITH READINGS FROM THE LOWER 50S IN
THE MOUNTAINS TO THE LOWER 60S IN THE EAST. INCREASED POPS TO LIKELY
ON SATURDAY WITH NAM...GFS AND ECMWF ALL SUPPORTING THUNDERSTORMS.
ROBUST CAPES OFF THE GFS FROM 1 TO 3K J/KG LEAD TO POTENTIAL FOR
STRONGER STORMS IN SOUTHSIDE. A PULSE TYPE SEVERE STORM MAY BE
POSSIBLE WITH WIND AND RAIN. TRAINING OF ECHOES COULD RESULT IN
FLOODING PROBLEMS WITH HIGHER PWAT VALUES. WENT WITH COOLER HIGHS
FOR SATURDAY IN THE 70S WITH BETTER COVERAGE AND THICK CLOUDS. HELD
ON TO CHANCE OF SHOWERS SATURDAY NIGHT...WITH LOWS FROM THE MID 50S
IN THE MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SUNDAY...BIT WITH A
SHORT WAVE OVER THE SOUTHERN APPALACHIANS. MODELS DIFFER IN THE
SURFACE REFLECTION OF THE SOUTHERN WAVE. MAIN FRONT WILL BE TO THE
NORTH OF THE FORECAST AREA BUT INFLUENCE OF THE SOUTHERN
APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN BETTER AREAL
COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 105 AM EDT THURSDAY...
HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE OVERNIGHT INTO
MUCH OF THURSDAY WITH JUST SOME MID/HIGH CLOUDS THROUGH EARLY
MORNING. MAY SEE SOME LOWER STRATO-CU REACH KLWB AROUND DAYBREAK
ASSOCIATED WITH CONVECTION TO THE NORTH BUT STILL APPEARS ABOVE
MVFR LEVELS FOR NOW. WEST WINDS WILL REMAIN GUSTY ALONG THE RIDGES
OVERNIGHT AND MAY SEE PERIODIC GUSTS AT KROA LINGER THRU MORNING.
OTRW SHOULD SEE LIGHTER WINDS OVERNIGHT BEFORE ONCE AGAIN GUSTING
15-25 KTS DURING THE DAY ON THURSDAY.
EXPECT A BROAD AREA OF SCTD/BKN CI/AC TO INIT THURSDAY...THEN MORE
CU AS HEATING DEVELOPS AHEAD OF A COLD FRONT SAGGING IN FROM THE
NORTH. THIS BOUNDARY SHOULD ALSO ACT TO PRODUCE SCATTERED SHOWERS
AND THUNDERSTORMS BY MID AFTERNOON AND EVENING ON THURSDAY. AT
THIS POINT APPEARS LOCATIONS ACROSS SE WVA...NAMELY KLWB...AND OUT
EAST AROUND KLYH HAVE THE BEST SHOT AT SEEING A BAND OF LATE DAY
SHRA/TSRA. THUS INCLUDED A VCTS/CB MENTION AT THESE LOCATIONS
AFTER 19Z/3PM AND A PREVAILING -SHRA MENTION AT KLWB DURING THE
EARLY EVENING. ELSW LOW CONFIDENCE IN SEEING TSRA GIVEN DEEP
WESTERLY FLOW BUT IF CONVECTION CAN ORGANIZE INTO MORE OF A LINE
FEATURE TO THE NORTH THEN ISOLATED -TSRA COULD AFFECT MUCH OF THE
REGION ESPCLY AFTER 00Z/8PM. OTRW APPEARS ANY AREAS OF MVFR IN
SHRA/TSRA SHOULD END LATE THURSDAY EVENING WITH MAINLY VFR CIGS
AND SOME LATE NIGHT MVFR VSBYS IN FOG PENDING EARLIER RAINFALL.
FRIDAY THROUGH THE WEEKEND WILL BE A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASSING ALOFT WILL OFFER UPPER LEVEL SUPPORT. PERIODS OF MVFR/IFR
ARE POSSIBLE DURING ANY TIMES OF SHOWERS AND THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...AMS
AVIATION...CF/JH
000
FXUS61 KRNK 160522
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
122 AM EDT THU MAY 16 2013
.SYNOPSIS...
A COLD FRONT IN THE OHIO VALLEY WILL DRIFT SLOWLY SOUTH ACROSS THE
MID ATLANTIC REGION THURSDAY BEFORE REACHING THE BLUE RIDGE FRIDAY
INTO FRIDAY NIGHT. THIS FRONT WILL REMAIN IN THE AREA THROUGH THE
WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER AND THUNDERSTORM
ACTIVITY...MAINLY EACH AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 400 PM EDT WEDNESDAY...
LOOKING AT RELATIVELY CLEAR SKIES THROUGH THE REMAINDER OF THE
EVENING NOW THAT MID LEVEL CLOUDS ARE EXITING THE EAST. MAY SEE A
FEW CLOUDS POP UP ALONG THE RIDGELINES...HOWEVER THESE WILL
DIMINISH AT SUNSET AS DAYTIME HEATING ENDS. WEST WINDS REMAIN
GUSTY AND CHINOOK-LIKE THIS AFTERNOON...AND WHEN COMBINED WITH
UPPER LEVEL RIDGING ALONG THE APPALACHIAN CHAIN HAVE ALLOWED HIGHS
TODAY TO CLIMB FROM THE MID 80S TO NEAR 90 EAST...AND THE UPPER
70S TO LOW 80S ACROSS THE MOUNTAINS.
OVERNIGHT...SURFACE WINDS WILL DECREASE WITH THE LOSS OF DAYTIME
HEATING...BUT WILL AGAIN SEE WINDS BECOME SOMEWHAT GUSTY ALONG THE
RIDGES AS ANOTHER WEAK TROUGH PASSES ACROSS THE REGION...REACHING
35 TO 40 MPH AT TIMES AT THE HIGHEST PARTS OF THE NORTH CAROLINA
MOUNTAINS INTO GRAYSON COUNTY. WILL ALSO SEE HIGH CLOUDS INCREASE
THROUGH THE NIGHT AS A COLD FRONT SINKS FROM THE GREAT LAKES
TOWARD THE OHIO RIVER VALLEY...AND EXPECT TO SEE A CANOPY OF
CIRRUS ACROSS THE AREA AT SUNRISE. DESPITE UPPER LEVEL RIDGING
BREAKING DOWN OVERNIGHT...WILL STILL SEE WARM AIR BUILD IN AHEAD
OF THE APPROACHING COLD FRONT...WITH OVERNIGHT LOWS RANGING FROM
THE MID 50S TO LOW 60S MOST AREAS.
CLOUD COVER AND SHOWER ACTIVITY WILL INCREASE THROUGH THE DAY ON
THURSDAY AS THE COLD FRONT CONTINUES ITS SOUTHWARD PUSH. MAY SEE A
FEW THUNDERSTORMS DEVELOP ACROSS THE MOUNTAINS WITH AFTERNOON
HEATING...A FEW OF WHICH MAY BECOME STRONG FOR BRIEF PERIODS OF
TIME...HOWEVER BETTER INSTABILITY IS EXPECTED TO REMAIN TO THE
NORTH OF OUR AREA. INCREASED CLOUD COVER WILL HELP LIMIT
HEATING...ALTHOUGH AFTERNOON HIGHS WILL STILL BE WARM...RANGING
FROM THE UPPER 70S WEST TO THE MID/UPPER 80S EAST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
SIMILAR TO PAST FEW DAYS HIGHEST PROBABILITY OF PRECIPITATION WILL
LINE UP ALONG AND JUST SOUTH OF THE FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES WITH THE BEST AREAL COVERAGE IN THE AFTERNOON
AND EVENING. GFS AND NAM BROUGHT FRONT AND HIGHER CONVECTIVE
AVAILABLE POTENTIAL ENERGY INTO THE NORTHERN COUNTY WARNING AREA ON
FRIDAY THEN CLOSER TO THE VIRGINIA/NORTH CAROLINA BORDER ON
SATURDAY. 850MB BOUNDARY DOES NOT ADVANCE AS FAR SOUTH SO IT SEEMS
FORECAST AREA WILL BE IN THE BAROCLINIC ZONE. SHORT WAVE COMING OUT
OF THE SOUTHERN PLAINS AND MCS ACTIVITY MAY ALSO INFLUENCE POSITION
OF THE FRONT AND THEREFORE THE MOST LIKELY LOCATION FOR
PRECIPITATION.
LITTLE CHANGE IN AIR MASS THIS TIME FRAME. OF COURSE VARIATION IN
DAYTIME HIGH TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND
LOCATION OF RAINFALL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SATURDAY NIGHT AND
SUNDAY...BIT WITH A SHORT WAVE OVER THE SOUTHERN APPALACHIANS.
MODELS DIFFER IN THE SURFACE REFLECTION OF THE SOUTHERN WAVE.
MAIN FRONT WILL BE TO THE NORTH OF THE FORECAST AREA BUT INFLUENCE
OF THE SOUTHERN APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN
BETTER AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AS OF 105 AM EDT THURSDAY...
HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE OVERNIGHT INTO
MUCH OF THURSDAY WITH JUST SOME MID/HIGH CLOUDS THROUGH EARLY
MORNING. MAY SEE SOME LOWER STRATO-CU REACH KLWB AROUND DAYBREAK
ASSOCIATED WITH CONVECTION TO THE NORTH BUT STILL APPEARS ABOVE
MVFR LEVELS FOR NOW. WEST WINDS WILL REMAIN GUSTY ALONG THE RIDGES
OVERNIGHT AND MAY SEE PERIODIC GUSTS AT KROA LINGER THRU MORNING.
OTRW SHOULD SEE LIGHTER WINDS OVERNIGHT BEFORE ONCE AGAIN GUSTING
15-25 KTS DURING THE DAY ON THURSDAY.
EXPECT A BROAD AREA OF SCTD/BKN CI/AC TO INIT THURSDAY...THEN MORE
CU AS HEATING DEVELOPS AHEAD OF A COLD FRONT SAGGING IN FROM THE
NORTH. THIS BOUNDARY SHOULD ALSO ACT TO PRODUCE SCATTERED SHOWERS
AND THUNDERSTORMS BY MID AFTERNOON AND EVENING ON THURSDAY. AT
THIS POINT APPEARS LOCATIONS ACROSS SE WVA...NAMELY KLWB...AND OUT
EAST AROUND KLYH HAVE THE BEST SHOT AT SEEING A BAND OF LATE DAY
SHRA/TSRA. THUS INCLUDED A VCTS/CB MENTION AT THESE LOCATIONS
AFTER 19Z/3PM AND A PREVAILING -SHRA MENTION AT KLWB DURING THE
EARLY EVENING. ELSW LOW CONFIDENCE IN SEEING TSRA GIVEN DEEP
WESTERLY FLOW BUT IF CONVECTION CAN ORGANIZE INTO MORE OF A LINE
FEATURE TO THE NORTH THEN ISOLATED -TSRA COULD AFFECT MUCH OF THE
REGION ESPCLY AFTER 00Z/8PM. OTRW APPEARS ANY AREAS OF MVFR IN
SHRA/TSRA SHOULD END LATE THURSDAY EVENING WITH MAINLY VFR CIGS
AND SOME LATE NIGHT MVFR VSBYS IN FOG PENDING EARLIER RAINFALL.
FRIDAY THROUGH THE WEEKEND WILL BE A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASSING ALOFT WILL OFFER UPPER LEVEL SUPPORT. PERIODS OF MVFR/IFR
ARE POSSIBLE DURING ANY TIMES OF SHOWERS AND THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...NF
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...CF/JH
000
FXUS61 KRNK 152352
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
752 PM EDT WED MAY 15 2013
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM PASSING NORTH OF THE GREAT LAKES WILL
DRAG A COLD FRONT SOUTHWARD TOWARDS THE OHIO RIVER VALLEY
TONIGHT...ON ITS WAY TO THE NORTHERN PORTION OF OUR FORECAST
REGION THURSDAY NIGHT AND FRIDAY. THIS FRONT WILL REMAIN IN THE
AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY EACH AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 400 PM EDT WEDNESDAY...
LOOKING AT RELATIVELY CLEAR SKIES THROUGH THE REMAINDER OF THE
EVENING NOW THAT MID LEVEL CLOUDS ARE EXITING THE EAST. MAY SEE A
FEW CLOUDS POP UP ALONG THE RIDGELINES...HOWEVER THESE WILL
DIMINISH AT SUNSET AS DAYTIME HEATING ENDS. WEST WINDS REMAIN
GUSTY AND CHINOOK-LIKE THIS AFTERNOON...AND WHEN COMBINED WITH
UPPER LEVEL RIDGING ALONG THE APPALACHIAN CHAIN HAVE ALLOWED HIGHS
TODAY TO CLIMB FROM THE MID 80S TO NEAR 90 EAST...AND THE UPPER
70S TO LOW 80S ACROSS THE MOUNTAINS.
OVERNIGHT...SURFACE WINDS WILL DECREASE WITH THE LOSS OF DAYTIME
HEATING...BUT WILL AGAIN SEE WINDS BECOME SOMEWHAT GUSTY ALONG THE
RIDGES AS ANOTHER WEAK TROUGH PASSES ACROSS THE REGION...REACHING
35 TO 40 MPH AT TIMES AT THE HIGHEST PARTS OF THE NORTH CAROLINA
MOUNTAINS INTO GRAYSON COUNTY. WILL ALSO SEE HIGH CLOUDS INCREASE
THROUGH THE NIGHT AS A COLD FRONT SINKS FROM THE GREAT LAKES
TOWARD THE OHIO RIVER VALLEY...AND EXPECT TO SEE A CANOPY OF
CIRRUS ACROSS THE AREA AT SUNRISE. DESPITE UPPER LEVEL RIDGING
BREAKING DOWN OVERNIGHT...WILL STILL SEE WARM AIR BUILD IN AHEAD
OF THE APPROACHING COLD FRONT...WITH OVERNIGHT LOWS RANGING FROM
THE MID 50S TO LOW 60S MOST AREAS.
CLOUD COVER AND SHOWER ACTIVITY WILL INCREASE THROUGH THE DAY ON
THURSDAY AS THE COLD FRONT CONTINUES ITS SOUTHWARD PUSH. MAY SEE A
FEW THUNDERSTORMS DEVELOP ACROSS THE MOUNTAINS WITH AFTERNOON
HEATING...A FEW OF WHICH MAY BECOME STRONG FOR BRIEF PERIODS OF
TIME...HOWEVER BETTER INSTABILITY IS EXPECTED TO REMAIN TO THE
NORTH OF OUR AREA. INCREASED CLOUD COVER WILL HELP LIMIT
HEATING...ALTHOUGH AFTERNOON HIGHS WILL STILL BE WARM...RANGING
FROM THE UPPER 70S WEST TO THE MID/UPPER 80S EAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
SIMILAR TO PAST FEW DAYS HIGHEST PROBABILITY OF PRECIPITATION WILL
LINE UP ALONG AND JUST SOUTH OF THE FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES WITH THE BEST AREAL COVERAGE IN THE AFTERNOON
AND EVENING. GFS AND NAM BROUGHT FRONT AND HIGHER CONVECTIVE
AVAILABLE POTENTIAL ENERGY INTO THE NORTHERN COUNTY WARNING AREA ON
FRIDAY THEN CLOSER TO THE VIRGINIA/NORTH CAROLINA BORDER ON
SATURDAY. 850MB BOUNDARY DOES NOT ADVANCE AS FAR SOUTH SO IT SEEMS
FORECAST AREA WILL BE IN THE BAROCLINIC ZONE. SHORT WAVE COMING OUT
OF THE SOUTHERN PLAINS AND MCS ACTIVITY MAY ALSO INFLUENCE POSITION
OF THE FRONT AND THEREFORE THE MOST LIKELY LOCATION FOR
PRECIPITATION.
LITTLE CHANGE IN AIR MASS THIS TIME FRAME. OF COURSE VARIATION IN
DAYTIME HIGH TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND
LOCATION OF RAINFALL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SATURDAY NIGHT AND
SUNDAY...BIT WITH A SHORT WAVE OVER THE SOUTHERN APPALACHIANS.
MODELS DIFFER IN THE SURFACE REFLECTION OF THE SOUTHERN WAVE.
MAIN FRONT WILL BE TO THE NORTH OF THE FORECAST AREA BUT INFLUENCE
OF THE SOUTHERN APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN
BETTER AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 750 PM EDT WEDNESDAY...
HIGH CONFIDENCE THAT VFR CONDITIONS WILL PERSIST THROUGH THE 00Z
FRIDAY TAF PERIOD. ALL LOCATIONS ARE EITHER CLEAR OR JUST HAVE A FEW
LOW LEVEL CU HANGING AROUND. W/SW WINDS HAVE REMAINED
GUSTY...RANGING 15-20 KTS AT TIMES. EXPECT THE WINDS TO LIGHTEN UP A
BIT OVERNIGHT BEFORE ONCE AGAIN GUSTING 15-20KTS DURING THE DAY ON
THURSDAY. MAY SEE SOME LOW LEVEL CU APPROACH LWB THURSDAY MORNING
AHEAD OF AN APPROACHING COLD FRONT FROM THE NORTH.
SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION MID
AFTERNOON AND EVENING ON THURSDAY. AT THIS POINT CHANCES ARE TOO LOW
TO MENTION IN TAFS WITH THE EXCEPTION OF LWB...WHERE VCSH IS
MENTIONED BEGINNING AT 18Z. MID TO UPPER 50S DWPTS WILL ALLOW FOR
PATCHY FOG TO DEVELOP OVERNIGHT THURSDAY INTO FRIDAY MORNING IN
AREAS THAT RECEIVE RAINFALL TOMORROW.
FRIDAY THROUGH THE WEEKEND WILL BE A PERSISTENT PATTERN OF SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS AS WEAK IMPULSES
PASSING ALOFT WILL OFFER UPPER LEVEL SUPPORT. PERIODS OF MVFR/IFR
ARE POSSIBLE DURING ANY TIMES OF SHOWERS AND THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...CF
000
FXUS61 KRNK 152013 CCA
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT WED MAY 15 2013
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM PASSING NORTH OF THE GREAT LAKES WILL
DRAG A COLD FRONT SOUTHWARD TOWARDS THE OHIO RIVER VALLEY
TONIGHT...ON ITS WAY TO THE NORTHERN PORTION OF OUR FORECAST
REGION THURSDAY NIGHT AND FRIDAY. THIS FRONT WILL REMAIN IN THE
AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY EACH AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 400 PM EDT WEDNESDAY...
LOOKING AT RELATIVELY CLEAR SKIES THROUGH THE REMAINDER OF THE
EVENING NOW THAT MID LEVEL CLOUDS ARE EXITING THE EAST. MAY SEE A
FEW CLOUDS POP UP ALONG THE RIDGELINES...HOWEVER THESE WILL
DIMINISH AT SUNSET AS DAYTIME HEATING ENDS. WEST WINDS REMAIN
GUSTY AND CHINOOK-LIKE THIS AFTERNOON...AND WHEN COMBINED WITH
UPPER LEVEL RIDGING ALONG THE APPALACHIAN CHAIN HAVE ALLOWED HIGHS
TODAY TO CLIMB FROM THE MID 80S TO NEAR 90 EAST...AND THE UPPER
70S TO LOW 80S ACROSS THE MOUNTAINS.
OVERNIGHT...SURFACE WINDS WILL DECREASE WITH THE LOSS OF DAYTIME
HEATING...BUT WILL AGAIN SEE WINDS BECOME SOMEWHAT GUSTY ALONG THE
RIDGES AS ANOTHER WEAK TROUGH PASSES ACROSS THE REGION...REACHING
35 TO 40 MPH AT TIMES AT THE HIGHEST PARTS OF THE NORTH CAROLINA
MOUNTAINS INTO GRAYSON COUNTY. WILL ALSO SEE HIGH CLOUDS INCREASE
THROUGH THE NIGHT AS A COLD FRONT SINKS FROM THE GREAT LAKES
TOWARD THE OHIO RIVER VALLEY...AND EXPECT TO SEE A CANOPY OF
CIRRUS ACROSS THE AREA AT SUNRISE. DESPITE UPPER LEVEL RIDGING
BREAKING DOWN OVERNIGHT...WILL STILL SEE WARM AIR BUILD IN AHEAD
OF THE APPROACHING COLD FRONT...WITH OVERNIGHT LOWS RANGING FROM
THE MID 50S TO LOW 60S MOST AREAS.
CLOUD COVER AND SHOWER ACTIVITY WILL INCREASE THROUGH THE DAY ON
THURSDAY AS THE COLD FRONT CONTINUES ITS SOUTHWARD PUSH. MAY SEE A
FEW THUNDERSTORMS DEVELOP ACROSS THE MOUNTAINS WITH AFTERNOON
HEATING...A FEW OF WHICH MAY BECOME STRONG FOR BRIEF PERIODS OF
TIME...HOWEVER BETTER INSTABILITY IS EXPECTED TO REMAIN TO THE
NORTH OF OUR AREA. INCREASED CLOUD COVER WILL HELP LIMIT
HEATING...ALTHOUGH AFTERNOON HIGHS WILL STILL BE WARM...RANGING
FROM THE UPPER 70S WEST TO THE MID/UPPER 80S EAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
SIMILAR TO PAST FEW DAYS HIGHEST PROBABILITY OF PRECIPITATION WILL
LINE UP ALONG AND JUST SOUTH OF THE FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES WITH THE BEST AREAL COVERAGE IN THE AFTERNOON
AND EVENING. GFS AND NAM BROUGHT FRONT AND HIGHER CONVECTIVE
AVAILABLE POTENTIAL ENERGY INTO THE NORTHERN COUNTY WARNING AREA ON
FRIDAY THEN CLOSER TO THE VIRGINIA/NORTH CAROLINA BORDER ON
SATURDAY. 850MB BOUNDARY DOES NOT ADVANCE AS FAR SOUTH SO IT SEEMS
FORECAST AREA WILL BE IN THE BAROCLINIC ZONE. SHORT WAVE COMING OUT
OF THE SOUTHERN PLAINS AND MCS ACTIVITY MAY ALSO INFLUENCE POSITION
OF THE FRONT AND THEREFORE THE MOST LIKELY LOCATION FOR
PRECIPITATION.
LITTLE CHANGE IN AIR MASS THIS TIME FRAME. OF COURSE VARIATION IN
DAYTIME HIGH TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND
LOCATION OF RAINFALL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SATURDAY NIGHT AND
SUNDAY...BIT WITH A SHORT WAVE OVER THE SOUTHERN APPALACHIANS.
MODELS DIFFER IN THE SURFACE REFLECTION OF THE SOUTHERN WAVE.
MAIN FRONT WILL BE TO THE NORTH OF THE FORECAST AREA BUT INFLUENCE
OF THE SOUTHERN APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN
BETTER AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM EDT WEDNESDAY...
EXPECT VFR CONDITIONS FOR ALL AIRPORTS THROUGH THE 15/18Z TAF
PERIOD.
THROUGH THE REMAINDER OF WEDNESDAY...SCT MID LEVEL CLOUDS IN THE
VICINITY OF DAN AND LYH WILL CONTINUE EAST...MAKING FOR CLEAR TO
MOSTLY CLEAR SKIES...POSSIBLY WITH A FEW AFTERNOON CU. WINDS WILL
REMAIN GUSTY FROM THE WEST...OCCASIONALLY REACHING 25KTS FOR ROA
AND POINTS WESTWARD...AND 20KTS AT DAN AND LYH. WIND SPEEDS WILL
DIMINISH WITH SUNSET.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE TONIGHT WITH
A RIBBON OF LOWER CEILINGS LIKELY PRECEDING THE BOUNDARY ACROSS
THE FAR NORTH AROUND 16/12Z. MID AND HIGH CLOUDS WILL THICKEN
AFTER SUNRISE THURSDAY...AND LOW CLOUDS MAY APPROACH CLOSE ENOUGH
TO LWB FOR A LOW END VFR STRATO-CU DECK TO SETTLE ACROSS THE
FIELD.
SHOWER ACTIVITY WILL INCREASE FROM THE NORTH ON THURSDAY AS THE
FRONT SINKS FURTHER TO THE SOUTH...WITH SOME SHOWERS DEVELOPING
INTO THUNDERSTORMS DURING LATE MORNING WITH DAYTIME HEATING. AT
THIS TIME...BELIEVE BEST COVERAGE OF CONVECTION WILL BE DURING MID
AFTERNOON AND EVENING...WITH BETTER CHANCES ACROSS THE MOUNTAINS.
THURSDAY BEGINS A PERIOD OF SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY THAT WILL LAST THROUGH THE WEEKEND AS THE FRONT STALLS
JUST NORTH OF THE FORECAST AREA...WITH WEAK IMPULSES PASSING ALOFT
TO OFFER UPPER LEVEL SUPPORT. APPEARS THE AFTERNOON AND EARLY
EVENING HOURS WOULD HAVE THE BEST CHANCE OF SEEING PERIODS OF
MVFR/IFR IN SHRA/TSRA...ESPECIALLY FRIDAY INTO SUNDAY AFTERNOON
PENDING WHERE THE FRONT ENDS UP. WILL ALSO SEE PATCHY FOG DURING
THE OVERNIGHTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JH/NF
000
FXUS61 KRNK 151957
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT WED MAY 15 2013
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM PASSING NORTH OF THE GREAT LAKES WILL
DRAG A COLD FRONT SOUTHWARD TOWARDS THE OHIO RIVER VALLEY
TONIGHT...ON ITS WAY TO THE NORTHERN PORTION OF OUR FORECAST
REGION THURSDAY NIGHT AND FRIDAY. THIS FRONT WILL REMAIN IN THE
AREA THROUGH THE WEEKEND...PROVIDING THE FOCUS FOR SPOTTY SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY EACH AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 400 PM EDT WEDNESDAY...
LOOKING AT RELATIVELY CLEAR SKIES THROUGH THE REMAINDER OF THE
EVENING NOW THAT MID LEVEL CLOUDS ARE EXITING THE EAST. MAY SEE A
FEW CLOUDS POP UP ALONG THE RIDGELINES...HOWEVER THESE WILL
DIMINISH AT SUNSET AS DAYTIME HEATING ENDS. WEST WINDS REMAIN
GUSTY AND CHINOOK-LIKE THIS AFTERNOON...AND WHEN COMBINED WITH
UPPER LEVEL RIDGING ALONG THE APPALACHIAN CHAIN HAVE ALLOWED HIGHS
TODAY TO CLIMB FROM THE MID 80S TO NEAR 90 EAST...AND THE UPPER
70S TO LOW 80S ACROSS THE MOUNTAINS.
OVERNIGHT...SURFACE WINDS WILL DECREASE WITH THE LOSS OF DAYTIME
HEATING...BUT WILL AGAIN SEE WINDS BECOME SOMEWHAT GUSTY ALONG THE
RIDGES AS ANOTHER WEAK TROUGH PASSES ACROSS THE REGION...REACHING
35 TO 40 MPH AT TIMES AT THE HIGHEST PARTS OF THE NORTH CAROLINA
MOUNTAINS INTO GRAYSON COUNTY. WILL ALSO SEE HIGH CLOUDS INCREASE
THROUGH THE NIGHT AS A COLD FRONT SINKS FROM THE GREAT LAKES
TOWARD THE OHIO RIVER VALLEY...AND EXPECT TO SEE A CANOPY OF
CIRRUS ACROSS THE AREA AT SUNRISE. DESPITE UPPER LEVEL RIDGING
BREAKING DOWN OVERNIGHT...WILL STILL SEE WARM AIR BUILD IN AHEAD
OF THE APPROACHING COLD FRONT...WITH OVERNIGHT LOWS RANGING FROM
THE MID 50S TO LOW 60S MOST AREAS.
CLOUD COVER AND SHOWER ACTIVITY WILL INCREASE THROUGH THE DAY ON
THURSDAY AS THE COLD FRONT CONTINUES ITS SOUTHWARD PUSH. MAY SEE A
FEW THUNDERSTORMS DEVELOP ACROSS THE MOUNTAINS WITH AFTERNOON
HEATING...A FEW OF WHICH MAY BECOME STRONG FOR BRIEF PERIODS OF
TIME...HOWEVER BETTER INSTABILITY IS EXPECTED TO REMAIN TO THE
NORTH OF OUR AREA. INCREASED CLOUD COVER WILL HELP LIMIT
HEATING...ALTHOUGH AFTERNOON HIGHS WILL STILL BE WARM...RANGING
FROM THE UPPER 70S WEST TO THE MID/UPPER 80S EAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
SIMILAR TO PAST FEW DAYS HIGHEST PROBABILITY OF PRECIPITATION WILL
LINE UP ALONG AND JUST SOUTH OF THE FRONT ACROSS THE OHIO VALLEY AND
MID ATLANTIC STATES WITH THE BEST AREAL COVERAGE IN THE AFTERNOON
AND EVENING. GFS AND NAM BROUGHT FRONT AND HIGHER CONVECTIVE
AVAILABLE POTENTIAL ENERGY INTO THE NORTHERN COUNTY WARNING AREA ON
FRIDAY THEN CLOSER TO THE VIRGINIA/NORTH CAROLINA BORDER ON
SATURDAY. 850MB BOUNDARY DOES NOT ADVANCE AS FAR SOUTH SO IT SEEMS
FORECAST AREA WILL BE IN THE BAROCLINIC ZONE. SHORT WAVE COMING OUT
OF THE SOUTHERN PLAINS AND MCS ACTIVITY MAY ALSO INFLUENCE POSITION
OF THE FRONT AND THEREFORE THE MOST LIKELY LOCATION FOR
PRECIPITATION.
LITTLE CHANGE IN AIR MASS THIS TIME FRAME. OF COURSE VARIATION IN
DAYTIME HIGH TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND
LOCATION OF RAINFALL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM EDT WEDNESDAY...
LARGE SCALE UPPER RIDGE OVER THE FORECAST AREA SATURDAY NIGHT AND
SUNDAY...BIT WITH A SHORT WAVE OVER THE SOUTHERN APPALACHIANS.
MODELS DIFFER IN THE SURFACE REFLECTION OF THE SOUTHERN WAVE. MAIN FRONT WILL BE TO THE NORTH OF THE FORECAST AREA BUT INFLUENCE OF THE SOUTHERN APPALACHIANS FEATURE MAY BE ENOUGH TO RESULT IN BETTER AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY.
UPPER LOW CUTS OFF OVER THE DAKOTAS ON MONDAY. THE LOW MOVES EAST
THROUGH WEDNESDAY AND WILL PUSH A COLD FRONT INTO THE AREA BY
WEDNESDAY OR THURSDAY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM EDT WEDNESDAY...
EXPECT VFR CONDITIONS FOR ALL AIRPORTS THROUGH THE 15/18Z TAF
PERIOD.
THROUGH THE REMAINDER OF WEDNESDAY...SCT MID LEVEL CLOUDS IN THE
VICINITY OF DAN AND LYH WILL CONTINUE EAST...MAKING FOR CLEAR TO
MOSTLY CLEAR SKIES...POSSIBLY WITH A FEW AFTERNOON CU. WINDS WILL
REMAIN GUSTY FROM THE WEST...OCCASIONALLY REACHING 25KTS FOR ROA
AND POINTS WESTWARD...AND 20KTS AT DAN AND LYH. WIND SPEEDS WILL
DIMINISH WITH SUNSET.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE TONIGHT WITH
A RIBBON OF LOWER CEILINGS LIKELY PRECEDING THE BOUNDARY ACROSS
THE FAR NORTH AROUND 16/12Z. MID AND HIGH CLOUDS WILL THICKEN
AFTER SUNRISE THURSDAY...AND LOW CLOUDS MAY APPROACH CLOSE ENOUGH
TO LWB FOR A LOW END VFR STRATO-CU DECK TO SETTLE ACROSS THE
FIELD.
SHOWER ACTIVITY WILL INCREASE FROM THE NORTH ON THURSDAY AS THE
FRONT SINKS FURTHER TO THE SOUTH...WITH SOME SHOWERS DEVELOPING
INTO THUNDERSTORMS DURING LATE MORNING WITH DAYTIME HEATING. AT
THIS TIME...BELIEVE BEST COVERAGE OF CONVECTION WILL BE DURING MID
AFTERNOON AND EVENING...WITH BETTER CHANCES ACROSS THE MOUNTAINS.
THURSDAY BEGINS A PERIOD OF SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY THAT WILL LAST THROUGH THE WEEKEND AS THE FRONT STALLS
JUST NORTH OF THE FORECAST AREA...WITH WEAK IMPULSES PASSING ALOFT
TO OFFER UPPER LEVEL SUPPORT. APPEARS THE AFTERNOON AND EARLY
EVENING HOURS WOULD HAVE THE BEST CHANCE OF SEEING PERIODS OF
MVFR/IFR IN SHRA/TSRA...ESPECIALLY FRIDAY INTO SUNDAY AFTERNOON
PENDING WHERE THE FRONT ENDS UP. WILL ALSO SEE PATCHY FOG DURING
THE OVERNIGHTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JH/NF
000
FXUS61 KRNK 151816
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
216 PM EDT WED MAY 15 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST AND OFFSHORE THE SOUTHEAST COAST
TODAY ALLOWING FOR A RETURN SOUTHWEST FLOW OF VERY WARM AIR INTO
THIS AFTERNOON. DEEP LOW PRESSURE PASSING ACROSS THE NORTHERN
GREAT LAKES WILL LIFT AN ASSOCIATED WARM FRONT NORTH OF THE AREA
LATER TODAY WITH AN ASSOCIATED COLD FRONT APPROACHING FROM THE
NORTH BY EARLY THURSDAY. THIS FRONTAL BOUNDARY WILL DROP SOUTH
INTO THE REGION LATER THURSDAY BEFORE STALLING OVER OR NEAR THE
AREA INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT WEDNESDAY...
SURFACE OBSERVATIONS INDICATE THAT WIND SPEEDS ACROSS THE NORTH
CAROLINA MOUNTAINS INTO GRAYSON COUNTY ARE COMING DOWN
SIGNIFICANTLY FROM THE STRONGER GUSTS OF THE OVERNIGHT...AND
THEREFORE HAVE CANCELLED THE WIND ADVISORY FOR THAT AREA. THAT
STATED...THE PRESSURE GRADIENT BETWEEN A DEEP LOW PRESSURE SYSTEM
NORTH OF THE GREAT LAKES AND HIGH PRESSURE OFF THE COAST WILL
REMAIN TIGHT TODAY...AND WE CAN EXPECT ANOTHER ROUND OF GUSTY WEST
WINDS THROUGH THE DAY...OCCASIONALLY REACHING 25 MPH AT TIMES.
THIS DOWNSLOPE WIND...WHEN COMBINED WITH INCREASED RIDGING IN THE
UPPER LEVELS...WILL RESULT IN SOME OF THE WARMEST TEMPERATURES
THIS FAR INTO THE YEAR...WITH AFTERNOON HIGHS PUSHING THE UPPER
80S TO 90 EAST OF THE BLUE RIDGE...AND UPPER 70S TO MID 80S ACROSS
THE MOUNTAINS. SCATTERED CLOUDS SOUTH OF THE INTERSTATE 81
CORRIDOR ARE EXPECTED TO PUSH OUT OF THE AREA BY EARLY
AFTERNOON...MAKING FOR MOSTLY SUNNY SKIES THEREAFTER.
UPPER RIDGING WILL BREAKDOWN SOMEWHAT OVERNIGHT AS A COLD FRONT
TO THE NORTH SAGS SOUTH. WINDS ABOVE THE SURFACE AHEAD OF THE
FRONT WILL AGAIN INCREASE AS A WEAK MID LEVEL TROF SWINGS BY TO
THE NORTHEAST OVERNIGHT. HOWEVER SOUNDINGS SHOW LESS MIXING DOWN
ACROSS THE HIGHER ELEVATIONS WITH MORE MOISTURE IN PLACE SO NOT
EXPECTING A REPEAT OF THIS EARLY MORNINGS GUSTS OVER THE MOUNTAINS.
OTHERWISE...CLOUDS AHEAD OF THE BOUNDARY WILL INCREASE SOME
LATE...WITH PERHAPS A THIN BAND OF SHOWERS NEARING THE FAR
NORTHWEST. SINCE LATEST MODELS ARE SLOWER GIVEN THE STRONG
RIDGING...ONLY KEPT A VERY LOW CHANCE OF RAIN...WITH SKIES
MAINLY CLEAR OVER THE SOUTHERN HALF OF THE FORECAST AREA THROUGH
MORNING AND BECOMING PARTLY CLOUDY ELSEWHERE. QUITE A WARM AND
ALMOST MUGGY NIGHT WITH DEWPOINTS JUMPING INTO THE 50S AND LIGHT
MIXING/WARM ADVECTION KEEPING LOWS 60-65 ON THE RIDGES AND...WITH
ONLY THE VALLEYS SEEING SOME 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
UNSETTLED PERIOD WITH FRONTAL BOUNDARY TRAVELING ACROSS
OUR REGION. WITH BROAD MID LEVEL RIDGING OVER THE AREA
INITIALLY...SLOWED DOWN THE ADVANCE OF POPS THURSDAY
MORNING. BY THURSDAY AFTERNOON...H5 TROUGH WILL ROLL
ACROSS THE MISSISSIPPI RIVER VALLEY. FRONTAL BOUNDARY
WILL SLOW DROP SOUTH THURSDAY. PLACED THE HIGHEST POPS
ACROSS THE NORTHWEST ON THURSDAY. HIGH TEMPERATURES ON
THURSDAY WILL BE COOLER THAN TODAY BECAUSE OF ADDITIONAL
CLOUD COVER WITH READINGS FROM THE UPPER 60S IN THE
NORTHWEST TO THE MID 80S IN THE SOUTHEAST.
A WEAKENING AREA OF LOW PRESSURE WILL TRAVEL EAST ACROSS THE
TENNESSEE VALLEY THURSDAY NIGHT...THEN MOVES INTO THE SOUTHERN
APPALACHIANS FRIDAY. MOISTURE WILL INCREASE AND CLOUDS THICKEN
AND LOWER THURSDAY NIGHT. KEPT THE HIGHER POPS IN THE WEST.
EXPECT A MILD THURSDAY NIGHT WITH CLOUDS AND SOUTHERLY
FLOW...WITH LOWS FROM LOWER 50S IN THE WEST TO LOWER 60S IN THE
EAST.
ON FRIDAY...A SHORTWAVE ROTATING THROUGH THE UPPER TROUGH OVER
NEW ENGLAND WILL PUSH THE FRONTAL BOUNDARY SOUTH...THEN IT
RETREATS BACK NORTHWARD BY FRIDAY NIGHT. COMBINATION OF BOTH THE
SHORT WAVE AND FRONT WILL BRING THE MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS INTO THE AREA. HIGHS ON FRIDAY WILL VARY FROM
UPPER 60S IN THE NORTHWEST TO LOWER TO MID 80S IN THE SOUTHEAST.
HARD TO PIN POINT POPS FOR FRIDAY NIGHT...BUT SHAPE TOWARDS
ECMWF/GFS BLEND WITH HIGHER POPS IN THE EAST. ANOTHER MILD AND
HUMID NIGHT WITH LOWS IN MID 50S TO LOWER 60S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
SEEING SIGNIFICANT DIFFERENCES BETWEEN THE 00Z/14 ECMWF AND
GFS BY SUNDAY WITH THE LONG WAVE TROF IN THE CENTRAL UNITED
STATES. ECMWF SHOWED A DISTINCT SOUTHERN PIECE OF THE TROF
AND WAS MUCH SLOWER THAN THE GFS.
STARTING OUT SATURDAY MORNING WITH THE SURFACE FRONT FROM
WISCONSIN INTO NORTHWESTERN VIRGINIA. BY SUNDAY THE FRONT HAS
MOVED BACK NORTH. LEANING TOWARD THE SLOWER ECMWF KEEPS THE
FORECAST AREA DEEP IN THE WARM UNSTABLE AIR THROUGH TUESDAY.
MODELS ALSO ARE TAKING THE UPPER LOW ACROSS THE ROCKIES...THEN
THE TENNESSEE VALLEY...THEN INTO THE SOUTHERN APPALACHIANS SUNDAY
NIGHT. SUSPECT THE DETAILS MAY NOT BE CORRECT THIS FAR OUT BUT
IDEA OF A SHORT WAVE CUTTING INTO THE EASTERN UPPER RIDGE IS
REASONABLE. MAY HAVE ENHANCED PROBABILITY OF PRECIPITATION WITH
ANY FEATURE LIKE THIS SATURDAY THROUGH TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM EDT WEDNESDAY...
EXPECT VFR CONDITIONS FOR ALL AIRPORTS THROUGH THE 15/18Z TAF
PERIOD.
THROUGH THE REMAINDER OF WEDNESDAY...SCT MID LEVEL CLOUDS IN THE
VICINITY OF DAN AND LYH WILL CONTINUE EAST...MAKING FOR CLEAR TO
MOSTLY CLEAR SKIES...POSSIBLY WITH A FEW AFTERNOON CU. WINDS WILL
REMAIN GUSTY FROM THE WEST...OCCASIONALLY REACHING 25KTS FOR ROA
AND POINTS WESTWARD...AND 20KTS AT DAN AND LYH. WIND SPEEDS WILL
DIMINISH WITH SUNSET.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE TONIGHT WITH
A RIBBON OF LOWER CEILINGS LIKELY PRECEDING THE BOUNDARY ACROSS
THE FAR NORTH AROUND 16/12Z. MID AND HIGH CLOUDS WILL THICKEN
AFTER SUNRISE THURSDAY...AND LOW CLOUDS MAY APPROACH CLOSE ENOUGH
TO LWB FOR A LOW END VFR STRATO-CU DECK TO SETTLE ACROSS THE
FIELD.
SHOWER ACTIVITY WILL INCREASE FROM THE NORTH ON THURSDAY AS THE
FRONT SINKS FURTHER TO THE SOUTH...WITH SOME SHOWERS DEVELOPING
INTO THUNDERSTORMS DURING LATE MORNING WITH DAYTIME HEATING. AT
THIS TIME...BELIEVE BEST COVERAGE OF CONVECTION WILL BE DURING MID
AFTERNOON AND EVENING...WITH BETTER CHANCES ACROSS THE MOUNTAINS.
THURSDAY BEGINS A PERIOD OF SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY THAT WILL LAST THROUGH THE WEEKEND AS THE FRONT STALLS
JUST NORTH OF THE FORECAST AREA...WITH WEAK IMPULSES PASSING ALOFT
TO OFFER UPPER LEVEL SUPPORT. APPEARS THE AFTERNOON AND EARLY
EVENING HOURS WOULD HAVE THE BEST CHANCE OF SEEING PERIODS OF
MVFR/IFR IN SHRA/TSRA...ESPECIALLY FRIDAY INTO SUNDAY AFTERNOON
PENDING WHERE THE FRONT ENDS UP. WILL ALSO SEE PATCHY FOG DURING
THE OVERNIGHTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF
| 
