Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 111416
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1016 AM EDT FRI APR 11 2014

.SYNOPSIS...
A COLD FRONT EXTENDED FROM NEW YORK TO SOUTHERN MISSOURI THIS
MORNING AND WILL CROSS THE OHIO VALLEY INTO NORTHEAST UNITED
STATES ON TODAY. THIS FRONT WILL WEAKEN AND STALL OVER THE MID
ATLANTIC REGION TONIGHT AND SATURDAY...BEFORE MOVING BACK NORTH
BY THE END OF THE WEEKEND. A MUCH STRONGER COLD FRONT WILL PUSH
THROUGH THE AREA FROM THE WEST ON MONDAY NIGHT AND TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT FRIDAY...

A WAVE OF LOW PRESSURE WAS ACROSS OHIO THIS MORNING WITH A
TRAILING COLD FRONT EXTENDED SOUTHWARD ALONG THE OHIO RIVER.
REGIONAL RADAR SHOWED THE MAIN BATCH OF PRECIPITATION IN EASTERN
OHIO AND WESTERN KENTUCKY. THIS FRONT WILL WEAKEN AS IT MOVES
SOUTHEAST THIS AFTERNOON AND STALLS OVER THE MID ATLANTIC REGION
TONIGHT. THE BEST CHANCE OF ANY RAIN WILL BE ACROSS NORTHWEST
PORTIONS OF CWA THIS AFTERNOON. MADE SOME MINOR ADJUSTMENTS IN
TEMPERATURES AND DEW POINTS FOR THIS MORNING INTO THIS AFTERNOON.
MORE ADJUSTMENT LATER...


AS OF 330 PM EDT THURSDAY...

ZONAL FLOW AT 500 MB TODAY AND TONIGHT. ELONGATED SHORT WAVE MOVES
EAST FROM THE OHIO VALLEY BUT NOT VERY FAR SOUTH. HAVE SLOWED DOWN
ARRIVAL OF PRECIPITATION IN THE NORTHWEST COUNTY WARNING AREA UNTIL
18Z/2PM. NAM AND RAP GUIDANCE SUGGESTING THAT PROBABILITY OF
PRECIPITATION FOR MUCH OF THE NORTHERN COUNTY WARNING AREA WILL
EVEN BE AFTER 00Z/8PM. RIGHT ALONG THE FRONT....SURFACE DEW POINTS
WILL BE CLOSE TO 50 DEGREES WITH PRECIPITABLE WATER VALUES AROUND
ONE INCH. SOUTH OF THE BOUNDARY...THE AIR MASS WILL BE DRIER.
SOUTHWEST WINDS WILL BECOME GUSTY THIS AFTERNOON...ESPECIALLY EAST
OF THE BLUE RIDGE.

STARTING OUT WARMER THIS MORNING THAN ON THURSDAY SO EXPECTING
MAXIMUM TEMPERATURES WILL ALSO BE WARMER. ENOUGH SUN IN ALL BUT THE
FAR NORTHWEST COUNTIES OF THE FORECAST AREA TO REACH VALUES CLOSE
TO MAV GUIDANCE. CLOUDS WILL LIMIT DROP IN TEMPERATURES TONIGHT.
WINDS WILL DIMINISH BUT STILL ENOUGH WIND SPEED MOST LOCATIONS FOR
NEAR SURFACE AIR TO STAY MIXED.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EDT FRIDAY...

DEEPENING TROUGH THROUGH THE WEST COAST AND ROCKIES SENDS
IMPRESSIVELY WARM AIR OUR WAY THIS WEEKEND. 80F IS POSSIBLE FOR THE
WARMER SPOTS BOTH SATURDAY AND SUNDAY. ALTHOUGH SURFACE WINDS WILL
CONTAIN MORE SOUTHERLY COMPONENT THIS WEEKEND...FOLLOWED THE DRIER
DEWPOINTS WITH DEEP MIXING EXPECTED BOTH DAYS. CLOUDS WILL INCREASE
SUNDAY NIGHT AHEAD OF A STRONG COLD FRONT ARRIVING EARLY NEXT WEEK.
CONSENSUS OF THE LONG RANGE MODEL SUITE HAS SLOWED DOWN ARRIVAL OF
PRECIP...SO KEEPING THE HIGHER POPS IN THE MONDAY NIGHT PERIOD. DEEP
SSE UPSLOPE FLOW MAY LEAD TO SHOWERS DEVELOPING ALONG THE SPINE OF
THE SOUTHERN BLUE RIDGE A LITTLE EARLIER ON MONDAY. DESPITE THE
CLOUDS AND AFTERNOON SHOWER CHANCES MAINLY ACROSS SW VA AND SE WEST
VA...TEMPS MAY SHOULD STILL REACH THE MIDDLE 60S BUT 70F AGAIN FOR
THE NC/VA PIEDMONT. MUCH COOLER ALONG THE SOUTHERN BLUE RIDGE WITH
THE UPSLOPE COMPONENT AND MORE PERSISTENT CLOUDS. WAVES OF LOW
PRESSURE MAY MOVE ALONG THE BOUNDARY LATE MONDAY NIGHT...STALLING
THE COLD FRONTAL PASSAGE UNTIL LATER TUESDAY...PERHAPS.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 114 PM EDT THURSDAY...

SOUTHWEST FLOW WILL LEAD TO INCREASING MOISTURE/DEWPOINTS AS WE HEAD
INTO MONDAY AHEAD OF A STRONG STORM SYSTEM MOVING FROM THE PLAINS
SUNDAY NIGHT INTO THE EASTERN U.S. BY TUESDAY. SYSTEM HAS TWO
DISTINCT STREAMS TO WORK WITH...AND QUESTION WILL BE WHETHER PHASING
OF NRN AND SRN STREAM OCCURS. 00Z ECMWF KEEP THE STREAMS UNPHASED
BUT SHOULD STILL SEE PLENTY OF GULF INFLOW AHEAD OF THE SRN STREAM
TO BRING AN INCREASED THREAT OF SHOWERS AND A FEW THUNDERSTORMS
MONDAY...WITH LIKELY TO CATEGORICAL POPS ARRIVING MONDAY
NIGHT/EARLY TUESDAY.

SEVERAL WAVES OF LOW PRESSURE ADVANCE NE ALONG THE FRONT AS IT
MOVES ACROSS OUR AREA MONDAY NIGHT-TUESDAY. A STRONGER SFC LOW
DEVELOPS OFF THE SOUTHEAST COAST/GA/FL TUESDAY NIGHT...WITH UPPER
SYSTEM CLOSING OFF HERE AS WELL WHICH COULD HANG THE FRONT UP
SOME. KEPT POPS IN THE EAST INTO TUESDAY NIGHT WITH DRY WX TAKING
PLACE WED-THU. APPEARS COLDER AIR WILL BE LAGGING ENOUGH TO KEEP
SNOW OUT OF THE FORECAST...BUT POTENTIAL EXISTS IF THE STORM
STRENGTHENS OR PHASES TO GET SOME WET SNOW IN THE HIGHER
ELEVATIONS OF THE SOUTHERN APPALACHIANS.

THERE WILL BE A STRONG SFC HIGH BUILDING SOUTH FROM QUEBEC BY
WEDNESDAY AFTERNOON...WITH FLOW TURNING NE. WEDGE SETS UP BUT CLOUD
COVER LOOKS MINIMAL SO ONLY A MODEST EFFECT ON TEMPS. AT THIS
TIME...KEEPING IT DRY THURSDAY WITH MOSTLY SUNNY SKIES BUT POTENTIAL
FOR RETURN MOISTURE INTO THE PIEDMONT EXISTS AS FLOW TURNS IN FROM
THE ATLANTIC.

TEMPS OVERALL THIS PERIOD WILL BE AT OR ABOVE NORMAL.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 135 AM EDT FRIDAY...

HIGH CONFIDENCE FOR VFR CEILINGS AND VISIBILITY THROUGH THE END
OF THE 06Z TAF FORECAST PERIOD. A WEAK COLD FRONT WILL APPROACH
FROM THE GREAT LAKES THIS AFTERNOON. CEILINGS WILL GRADUALLY LOWER
WITH INCREASING MID AND HIGH CLOUDS FROM THE WEST BUT WILL REMAIN
VFR. ENOUGH DEEP MIXING IS EXPECTED BY MID MORNING TO RESULT IN 20
TO 25 KNOT WIND GUSTS FROM THE SOUTHWEST.

ALTHOUGH NOT MENTIONED IN THE TAFS FOR LWB AND BLF...THERE WILL
BE A SLOWLY INCREASING THREAT FOR SCATTERED SHOWERS TOWARD
EVENING. AT THE MOMENT...THE CHANCE FOR THUNDER IS TOO LOW TO
MENTION.

.EXTENDED AVIATION DISCUSSION...
THE WEAK FRONT WILL STALL OVER SOUTHERN VIRGINIA FRIDAY NIGHT
INTO SATURDAY...BEFORE RETREATING NORTH BY SUNDAY. DUE TO WEAK
FORCING...IT APPEARS THAT CEILINGS AND VISIBILITIES MAY STAY
MOSTLY VFR. HOWEVER...THE THREAT FOR SHOWERS WILL LINGER WHILE THE
FRONT IS IN CLOSER TO BLF AND LWB. NO SIGNIFICANT IMPACT TO
AVIATION IS EXPECTED AT THE OTHER TAF SITES.

SUNDAY AND EARLY MONDAY SHOULD SEE A RETURN TO VFR FOR ALL SITES.
BY MONDAY AFTERNOON...A POTENT COLD FRONT WILL ARRIVE FROM THE
WEST TO TRIGGER A MORE WIDESPREAD CHANCE OF SHOWERS AND
THUNDERSTORMS...SOME WITH IFR/MVFR CONDITIONS. SHOWERS MAY
CONTINUE INTO TUESDAY...BUT THE LONG RANGE MODELS DIFFER
SIGNIFICANTLY ON HOW QUICKLY THE COLD FRONT WILL DEPART.

&&

.FIRE WEATHER...
AS OF 415 AM EDT FRIDAY...

BREEZY SOUTHWEST WINDS ARE EXPECTED TODAY AHEAD OF A SLOWLY
APPROACHING COLD FRONT. SOUTHWEST WINDS OF 10-15 MPH WITH GUSTS 20
TO 25 MPH WILL BE COMMON THIS AFTERNOON. AIR TEMPERATURES EAST OF
THE BLUE RIDGE WILL ALSO APPROACH 80 DEGREES WITH HUMIDITY VALUES
LOWERING TO AROUND 25 PERCENT. THESE CONDITIONS COUPLED WITH A HIGH
FIRE DANGER CLASS SUGGEST GREATER POTENTIAL FOR WILDLAND FIRE
ACTIVITY. WILL ISSUES A SPECIAL WEATHER STATEMENT FOR THE ENHANCED
THREAT.

&&

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

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...KM
LONG TERM...WP
AVIATION...AMS/PW
FIRE WEATHER...AMS/PM



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