Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 030540
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
140 AM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL DRIFT SLOWLY EAST TONIGHT AND THROUGH THE
CENTRAL APPALACHIANS BY EARLY TUESDAY. LOW PRESSURE WILL DEVELOP
ALONG THE FRONT TONIGHT AND MOVE NORTHEAST TOWARD THE MID-
ATLANTIC COAST BY TUESDAY MORNING. WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL ACCOMPANY THESE FEATURES. FOR WEDNESDAY THROUGH
FRIDAY...A DEEP UPPER LOW PRESSURE AREA WILL SAG SOUTHWARD FROM
THE GREAT LAKES INTO THE APPALACHIANS KEEPING AN UNSETTLED AND
UNSEASONABLY COOL WEATHER PATTERN ACROSS THE REGION.

&&

.NEAR TERM /THROUGH TODAY/...
AS 900 PM EDT MONDAY...

SEVERE THUNDERSTORM WATCH 138 REMAINS IN EFFECT UNTIL 10 PM
FOR VA/NC ALONG AND EAST OF THE BLUE RIDGE. SEVERE THUNDERSTORM
WATCH HAS BEEN CANCELLED IN WV AND WEST OF THE BLUE RIDGE IN VA.
FLASH FLOOD WATCH FOR GREENBRIER COUNTY HAS BEEN CANCELLED.

AS OF 900 PM...LINE OF DEEP CONVECTION EXTENDS FROM LYNCHBURG VA
TO WILKESBORO NC. MAIN THREAT GOING FORWARD IS PRIMARILY RAIN AND
LIGHTNING. STRONGER CELL CORES HAVE BEEN WEAKENING...VIL TRENDS
ARE DOWN. WITH LOSS OF DAYTIME HEATING...THIS DOWNWARD TREND
SHOULD CONTINUE WITH HAIL/WIND THREAT CONTINUING TO WANE.

A LITTLE CONCERNED THAT FORWARD MOVEMENT OF LINE WILL SLOW
RESULTING IN TRAINING OF CELLS OVER THE VA/NC PIEDMONT...SO DON`T
BE SURPRISED IF WE ISSUE A WARNING OR TWO FOR FLOODING. WILL HAVE
TO MONITOR THIS CLOSELY. AT THE VERY LEAST...HEALTHY SLUG OF WATER
IS GOING TO DRAIN INTO THE DAN RIVER BASIN...WHICH WILL RESULT IN
A SIGNIFICANT RISE ALONG THE DAN RIVER TUESDAY.

THE ACTUAL SURFACE COLD FRONT IS STILL WEST OF THE MOUNTAINS AND
IS NOT PROGGED TO MOVE EAST OF THE REGION UNTIL TUESDAY. THIS WILL
KEEP OUR FORECAST AREA IN THE WARM SECTOR FOR THE REMAINDER OF THE
NIGHT...TEMPERATURES REMAINING RELATIVELY MILD. WITH THE MOIST
BOUNDARY LAYER...ANY CLEARING WILL PROMOTE FOG FORMATION...SO
AREAS OF FOG/STRATUS CAN BE EXPECTED FOR SUNRISE TUESDAY.

LOW TEMPERATURES WILL RANGE FROM THE LOWER 50S IN THE WEST TO THE
LOWER 60S IN THE EAST. CONVECTION WILL MOVE EAST TUESDAY AND TAPER
OFF TUESDAY AFTERNOON INTO TUESDAY EVENING. HIGH TEMPERATURES
TUESDAY WILL RANGE FROM THE UPPER 50S IN THE NORTHWEST MOUNTAINS
TO THE MID 70S IN THE PIEDMONT.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 230 PM EDT MONDAY...

TUESDAY NIGHT INTO WEDNESDAY...AN UPPER LEVEL TROUGH OVER EASTERN
CANADA WILL BEGIN TO DIG SOUTHWARD INTO THE EASTERN GREAT LAKES.
THIS WILL SEND ANOTHER SURFACE FRONT THROUGH THE FORECAST AREA LATE
WEDNESDAY...BEGINNING A TREND TOWARD COOLER TEMPERATURES FOR THE
LATER HALF OF THE WEEK.  FRONTAL LIFT WILL PROVIDE A GOOD CHANCE OF
SHOWERS WEDNESDAY EVENING. PRIOR TO THE ARRIVAL OF THE FRONT LATE
WENDESDAY...TEMPERATURES FAVOR EARLY MAY NORMALS.

AFTER THE FRONTAL PASSAGE WEDNESDAY EVENING TEMPERATURES WILL TAKE A
SIGNIFICANT TUMBLE AS HIGH AMPLITUDE UPPER LEVEL TROUGH SINKS SOUTH
FROM THE GREAT LAKES AND A CUTOFF LOW DEVELOPS OVER THE MID ATLANTIC
REGION.  85H TEMPS OF 0 TO +5 DEG C ARE PROGGED TO BE OVER THE
FORECAST AREA BY THURSDAY NIGHT...SUPPRESSING TEMPERATURES AT LEAST
10 TO 15 DEGREES BELOW NORMAL.  AS THE UPPER LOW PASSES
OVERHEAD...COLD POOL ALOFT WILL COMBINE WITH DAYTIME HEATING FOR A
DAILY THREAT OF INSTABILITY SHOWERS AND CONSIDERABLE CLOUDINESS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...

CUTOFF WILL BE OVER THE AREA FRIDAY...THEN BEGIN TO WEAKEN AND DRIFT
EAST THIS WEEKEND AS FLOW ALOFT SLOWLY EVOLVES INTO A MORE
PROGRESSIVE PATTERN FOR THE SECOND WEEK OF MAY.  THE WEEKEND WILL BE
OUR TRANSITION BETWEEN THE TWO PATTERNS SO LOOK FOR SATURDAY TO BE
THE COOLER OF THE TWO DAYS BUT STILL RESEMBLING SOMETHING CLOSER TO
NORMAL WITH RESPECT TO TEMPERATURE...THEN TRENDING ABOVE NORMAL FOR
SUNDAY AND MONDAY.

CLOUDS AND SHOWERS WILL BE FOUND REGIONWIDE FRIDAY COURTESY OF THE
UPPER LOW. HIGHEST ELEVATIONS...SUCH AS MOUNT ROGERS...MAY EVEN TOY
WITH TEMPERATURES IN THE 30S. FOR THE WEEKEND...INCREASING
SUBSIDENCE IN THE WAKE OF THE UPPER LOW FAVORS MAINLY DRY
CONDITIONS...ALTHOUGH CAN`T RULE OUT A POP-UP SHOWER IN THE
MOUNTAINS.  SINCE POPS LESS THAN 20 PERCENT...REMOVED SHOWER THREAT
FOR ALL BUT THE WV HIGHLANDS. MODELS DO HINT AT ANOTHER FRONTAL
ENCROACHMENT MONDAY, SO MAINTAINED CHANCE THREAT MONDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM EDT TUESDAY...

A COLD FRONT IS SLOWLY PUSHING THROUGH THE MID ATLANTIC TONIGHT.
RAIN SHOWERS WILL CONTINUE AT KLYH AND KDAN FOR THE NEXT SEVERAL
HOURS. MOST TAF SITES ARE AT VFR NOW...BUT IT WILL NOT LAST AS ANY
CLEARING FROM THE RAIN COULD LEAD TO LOW CLOUDS AND PATCHY FOG.
SOME IFR/MVFR CONDITIONS ARE POSSIBLE ACROSS THE ENTIRE AREA...BUT
CONFIDENCE ON THE TIMING AND INTENSITY OF THE DETERIORIATING
FLYING WEATHER IS QUESTIONABLE. TO ACCOUNT FOR THE VARIABILITY OF
CONDITIONS TONIGHT...TEMPO GROUPS WERE ADDED FOR LOWER CEILINGS
AND VISIBILITIES AT ALL TAF SITES DURING THE REST OF THE NIGHT.

BY TUESDAY MORNING...CONDITIONS WILL SLOWLY IMPROVE WEST OF THE
BLUE RIDGE TO MVFR...WHILE THE PIEDMONT MAY REACH VFR FASTER. THE
COLD FRONT SLOWLY REACHES THE EAST COAST...AND BRINGS MORE SHOWERS
FOR KLYH AND KDAN DURING THE AFTERNOON. INSTABILITY IS CERTAINLY
MUCH WEAKER ON TUESDAY COMPARED TO MONDAY...WHICH RESULTS IN
THUNDER BEING LEFT OUT OF THESE TAFS DUE TO LOWER CONFIDENCE.
MEANWHILE...AN UPSLOPE NORTHWEST FLOW OVER THE MOUNTAINS COULD
BRING SCATTERED SHOWERS FOR KBLF AND KLWB BY THE AFTERNOON...BUT
THESE SHOWERS SHOULD NOT IMPEDE CONDITIONS TOO MUCH.

EXTENDED AVIATION DISCUSSION...

THE COLD FRONT DEPARTS OFFSHORE ON TUESDAY NIGHT...WHICH WILL
ALLOW ALL TAF SITES TO RETURN TO VFR. HOWEVER...A DEEP UPPER
LEVEL LOW FROM THE HUDSON BAY IN CANADA...SHOULD DIVE SOUTHWARD
TOWARD THE MID ATLANTIC ON WEDNESDAY. THIS UPPER LEVEL LOW SETTLES
OVER THE MID ATLANTIC THROUGH THE REMAINDER OF THIS WEEK. FLYING
CONDITIONS SHOULD REMAIN RATHER POOR DURING THIS TIME DUE TO
PERIODIC SHOWERS...LOW CEILINGS...AND PATCHY FOG.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...KK/RAB
NEAR TERM...KK/PM
SHORT TERM...PM
LONG TERM...PM
AVIATION...PW



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