Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 301417
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1017 AM EDT MON MAR 30 2015

.SYNOPSIS...
A COLD FRONT WILL SWEEP THROUGH THE REGION TODAY FOLLOWED BY WEAK
HIGH PRESSURE TONIGHT. A DRY COLD FRONT WILL THEN MOVE THROUGH THE
REGION TUESDAY FOLLOWED BY ANOTHER AREA OF WEAK HIGH PRESSURE FOR
WEDNESDAY. ANOTHER COLD FRONT WILL MOVE INTO THE REGION AND STALL
THURSDAY THROUGH FRIDAY...BRINGING AN EXTENDED PERIOD OF RAIN AND
MILD TEMPERATURES TO THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS 1017 AM EDT MONDAY...

ADJUSTED TEMPERATURES WITH LATEST SFC OBS AND TRENDED LATE
MORNING TEMPERATURES INTO THIS AFTERNOON TOWARDS THE LAMP
GUIDANCE. MODIFIED POPS AND WEATHER WITH LATEST WRS-88D RADAR
TRENDS AND BLEND OF HIRES-ARW AND HRRR. COLD FRONT WILL CONTINUE
TO MOVE EAST THIS AFTERNOON. THEN...HIGH PRESSURE WILL BUILD IN
FOR TONIGHT. MORE CHANGES LATER...


AS OF 345 AM EDT MONDAY...

FOCUS TODAY WILL BE ON A STRONG COLD SLATED TO SWEEP THROUGH THE
REGION FROM NORTHWEST TO SOUTHEAST THIS MORNING. THIS FRONT WILL
BRING A BRIEF PERIOD OF RAIN SHOWERS TO THE REGION FOLLOWED BY
GUSTY W-NW WINDS FROM MID-MORNING THROUGH THE AFTERNOON. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION AFTER SUNSET ALLOWING WINDS TO
DIMINISH.

DEWPOINTS REMAIN VERY LOW ACROSS THE REGION IN THE WAKE OF THE
ANTECEDENT ARCTIC HIGH PRESSURE SYSTEM NOW LOCATED JUST SOUTHEAST
OF THE CWA. ALTHOUGH THE UPPER SHORT WAVE IS STRONG...THE LACK OF
SFC-BASED MOISTURE WILL INHIBIT MUCH PRECIPITATION. LATEST MODELS
HAVE TRENDED DOWNWARD WITH FRONTAL ASSOCIATED PRECIPITATION
TODAY...AND THIS SEEMS PRUDENT GIVEN THE DRY AIR MASS IN PLACE.
THE BEST COMBINATION OF MOISTURE/DYNAMICS WILL TRACK TO THE
SOUTHWEST OF THE REGION...HENCE ROBBING THE AREAS TO THE NORTH OF
THE DEEPER MOISTURE AS WELL. DOWNSLOPE WINDS WILL ALSO NOT HELP. FOLLOWED
CLOSELY THE HRRR/GFS WITH RESPECT TO PRECIPITATION POTENTIAL AND
AMOUNTS TODAY...FOCUSING MAINLY ON THE MOUNTAINS FROM EASTERN WV
DOWN TO NORTHWEST NC...WITH A TREND TOWARD ZERO POPS ALL AREAS BY
MID-DAY AS THE SHORT WAVE/FRONT EXIT QUICKLY TO THE EAST. A
SECONDARY AREA OF BETTER POPS MAY BE EXPECTED ACROSS THE NC
PIEDMONT...BUT THIS SHOULD REMAIN MOSTLY SOUTHEAST OF THE CWA.
SERIOUSLY DOUBT THAT MUCH...IF ANY...MEASURABLE PRECIPITATION WILL
MAKE IT EAST OF THE BLUE RIDGE INTO THE VA PIEDMONT. WITH SFC
TEMPS REMAINING ABOVE FREEZING AND 850MB TEMPS ABOVE
FREEZING...THE LIKELIHOOD OF FROZEN PRECIPITATION HAS TRENDED
DOWNWARD. BUFKIT SOUNDINGS FROM BOTH THE NAM AND GFS SUPPORT THE
TREND TOWARD WHATEVER PRECIPITATION FALLS...FALLING AS LIQUID.
HOWEVER...WE ARE SEEING SNOW PELLETS HERE AT BCB/RNK SUGGEST THAT
THE VERY DRY SFC AIR ALLOWED FOR STRONG EVAPORATIVE COOLING TO
SUPPORT -SN/IP AS EARLIER EXPECTED. HOWEVER...BY THE TIME 850MB
TEMPS DROP BELOW 0C...THE PRECIPITATION HAS EXITED THE REGION.
UPSLOPE -SHSN/-SHRA IS EXPECTED TO LIMITED AT BEST WITH SFC WINDS
BEHIND THE FRONT WNW-W...AS OPPOSED TO A BETTER NW
DIRECTION...ALONG WITH INTRUSION OF MORE VERY DRY AIR.

WINDS WILL BE THE MAIN ISSUE TODAY...STOPPING JUST SHORT OF WIND
ADVISORY CRITERIA ALONG AND JUST EAST OF THE CREST OF THE BLUE
RIDGE. A FEW GUSTS FROM LATE MORNING THROUGH THE AFTERNOON OF
30-35KTS CANNOT BE RULED OUT. WILL MENTION IN THE HWO.

WITH DOWNSLOPE WINDS AND INCREASING SUNSHINE...TEMPERATURES EAST
OF THE BLUE RIDGE WILL LIKELY BE EVEN MILDER TODAY THAN THEY WERE
SUNDAY...REACHING THE LOW TO MID 60S. HIGHS IN THE 50S TO THE
WEST...WITH 40S IN THE MOUNTAINS OF WV. THE AIR MASS BEHIND THE
FRONT IS CONSIDERABLY WARMER THAN WHAT WE SAW OVER THE WEEKEND AND
HAS A HIGH PERCENTAGE OF PACIFIC-BASED AIR GIVEN THE INCREASING
ZONAL FLOW ALOFT. THUS...FEW...IF ANY AREAS WILL DROP BELOW
FREEZING TUE MORNING.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM EDT MONDAY...

LOOKING TO START TUESDAY OFF WITH SOUTHWESTERLY FLOW ESTABLISHED
ALONG THE CENTRAL APPALACHIAN CHAIN AS HIGH PRESSURE RESIDES OVER
THE SOUTHEAST STATES...WHILE A DEEP LOW PRESSURE SYSTEM PASSES
RAPIDLY EASTWARD ACROSS THE SOUTHERN GREAT LAKES. THE PRESSURE
GRADIENT ACROSS OUR AREA WILL CONTINUE TO TIGHTEN DURING THE MORNING
AND AFTERNOON AS THE LOW SHIFTS TOWARDS LOWER NEW ENGLAND...
RESULTING IN GUSTY WINDS THROUGH THE DAY...WHERE GUSTS WILL LIKELY
REACH 30 MPH...POSSIBLY AS HIGH AS 40 MPH AT TIMES IN A FEW AREAS.
WITH ABUNDANT SUNSHINE INTO THE EARLY AFTERNOON TO AID IN HEATING...
EXPECT AFTERNOON HIGHS TO REACH INTO THE 60S MOST LOCATIONS...
POSSIBLY 70 OVER THE SOUTHSIDE...JUST BEFORE THE LOW DRAGS A COLD
FRONT ACROSS OUR AREA DURING THE EVENING.

WILL SEE A FEW UPSLOPE RAIN SHOWERS DEVELOP ALONG THE WESTERN RIDGES
DURING TUESDAY EVENING AS THE COLD FRONT ENTERS OUR AREA...BRINGING
A NORTHWESTERLY WIND SHIFT. HIGH PRESSURE MOVING IN BEHIND THE COLD
FRONT WILL CAUSE WINDS TO VEER NORTH TUESDAY NIGHT...BRINGING AN END
TO ANY RESIDUAL SHOWER ACTIVITY AFTER ONLY A FEW HOURS. HIGH
PRESSURE WILL CONTINUE TO PUSH EAST ON WEDNESDAY...BECOMING CENTERED
OVER THE MID ATLANTIC COAST TO BUTT UP AGAINST THE EASTERN FACE OF
THE APPALACHIANS. WITH LITTLE COLD AIR INTRUSION ASSOCIATED WITH
THIS HIGH PRESSURE SYSTEM AND ABUNDANT SUNSHINE IN PLACE...AFTERNOON
HIGHS WILL RANGE FROM THE UPPER 50S ALONG INTERSTATE 64...TO THE
LOW/MID 60S ACROSS NORTHERN NORTH CAROLINA.

HIGH PRESSURE WILL PUSH OFF THE COAST ON THURSDAY...ALLOWING
SOUTHERLY FLOW TO BECOME MORE FIRMLY ESTABLISHED ALONG THE
APPALACHIAN CHAIN AS A STRONG COLD FRONT PASSES ACROSS THE PLAINS.
WILL NOT BE SURPRISED TO SEE A FEW SHOWERS DEVELOP IN THE STRONG
AFTERNOON HEATING ON THURSDAY AS WEAK DISTURBANCES PASS ACROSS THE
AREA. WEATHER MODELS ARE INDICATING MODEST INSTABILITY WHICH COULD
SUPPORT AN ISOLATED THUNDERSTORM OR TWO...BUT NOT ENOUGH CONFIDENCE
IN THAT RIGHT NOW TO PUT IT IN THE FORECAST. EXPECT THURSDAY
AFTERNOON HIGHS TO RANGE FROM THE MID 60S TO THE LOW 70S. RAIN
CHANCES WILL INCREASE THURSDAY NIGHT AS THE COLD FRONT PUSHES SOUTH
OF THE OHIO RIVER TOWARD DAWN ON FRIDAY. OVERNIGHT TEMPERATURES WILL
HOLD IN THE 50S.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 400 AM EDT MONDAY...

ON FRIDAY...A COLD FRONT WORKS SLOWLY SE INTO PA-KY LINE WITH THE
MAIN SFC LOW WELL INTO CANADA. ANOTHER WAVE OR TWO OF LOW PRESSURE
IS EXPECTED TO FORM ALONG THE FRONT FRIDAY AFTERNOON/EVENING. MODELS
SHOW INSTABILITY IN THE WARM SECTOR AND ADDED SOME THUNDER IN MOST
PLACES FRIDAY. STILL NOT GOING TO HAVE LIKELY POPS YET...AS MODELS
ARE NOT CONSISTENT WITH POTENTIAL FOR SEEING A BREAK IN THE ACTION
IN BETWEEN WAVES. AS WE HEAD INTO FRIDAY NIGHT-SATURDAY...THE ECMWF
KICKS THE FRONT EAST FAST BY ABOUT 5-8 HOURS...WITH GFS SLOWLY
EDGING IT SOUTHWARD WITH WEAKER LOW. WILL MAINTAIN SHOWER CHANCES
WITH HIGHER POPS FRIDAY NIGHT BEFORE WE START TO SEE DRYING BY SAT
AFTERNOON. A BRIEF SHOT OF COOLER/DRIER AIR...THOUGH CLOSER TO
NORMAL FOLLOWS THIS FRONT SAT NIGHT-SUNDAY.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...

FRONT APPEARS TO BE NEAR AN EKN-BLF-TRI LINE AT THIS HOUR. GUSTY
WEST WINDS ALREADY IN PLACE AT BLF...BUT TAKING A WHILE TO DEVELOP
EASTWARD AND AT LOWER ELEVATIONS. FRONT WILL PROGRESS QUICKLY TO
EAST OF THE BLUE RIDGE BY 15Z...WITH GUSTY W-WNW WINDS DEVELOPING
BEHIND THE FRONT. SCATTERED -SHRA AND EVEN BRIEF -SHSN/SHPL
OBSERVED AT THE ONSET OF THE PRECIPITATION IN THE VERY DRY
AIR...BUT THIS HAS PRETTY MUCH ALL ENDED NOW...WITH EITHER -RA/-DZ
THE MAIN P-TYPE AT THIS HOUR. SEVERAL MODELS SHOW PRECIPITATION
DISSIPATING EAST OF THE BLUE RIDGE...AS BEING VERIFIED BY
RADAR...WITH WEAK UPSLOPE DEVELOPING ACROSS THE WESTERN MOUNTAINS
THROUGH MID-MORNING AND A POSSIBLE BRIEF SURGE OF -SHRA INTO THE
SOUTHEAST PART OF THE CWA THROUGH MID-MORNING. QPF MOST AREAS
EXPECTED TO BE AROUND 0.01 INCH FROM THIS POINT FORWARD. CIGS
MOSTLY ACROSS THE MOUNTAINS OF EASTERN WV...LOW END VFR EAST OF
THE BLUE RIDGE...AND MVFR IN BETWEEN...I.E...BCB. CLEARING/DRYING
EAST OF THE ALLEGHANY FRONT WILL BE QUICK AFTER MID-MORNING AS
DOWNSLOPE WINDS DEVELOP...WHILE UPSLOPE CLOUDS AND IFR-MVFR CIGS
WILL LINGER ACROSS EASTERN WEST VIRGINIA INTO EARLY
AFTERNOON...THEN CLEARING IS EXPECTED THERE AS WELL. VFR CIGS ARE
EXPECTED AFT 00Z ALL SITES WITH JUST SCT 250. VFR VISIBILITIES ARE
EXPECTED...EXCEPT FOR A BRIEF PERIOD THROUGH 15Z ACROSS THE
MOUNTAINS OF EASTERN WEST VIRGINIA OF MVFR VSBYS IN -RA/-DZ.
WINDS...BECOMING WNW 10-15KTS WITH GUSTS 20-27KTS THROUGH LATE
AFTERNOON...BACKING TO THE SW 5-8KTS AFT 00Z.

MEDIUM CONFIDENCE IN CIGS THROUGH 00Z...THEN HIGH CONFIDENCE IN
VFR CIGS THROUGH THE REMAINDER OF THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID
PERIOD.

EXTENDED AVIATION FORECAST...

ANOTHER CLIPPER LIKE SYSTEM WILL TRACK ACROSS THE REGION TUE
INTO WED. STRONG/GUSTY WINDS WILL BE POSSIBLE WITH THIS
SYSTEM...BUT LITTLE CLOUD COVER/PRECIPITATION IS EXPECTED AS
ASSOCIATED LOW PRESSURE PASSES BY WELL TO THE NORTH OF THE REGION.
A QUASI-STATIONARY FRONTAL BOUNDARY WILL SET UP ACROSS THE REGION
FOR THE LATER HALF OF THE WEEK...LEAVING AN UNSETTLED PATTERN IN
PLACE UNTIL THE FRONT IS PUSHED SOUTH BY HIGH PRESSURE MOVING EAST
FROM THE MIDWEST. AN EXTENDED PERIOD OF MVFR TO LOCALLY IFR CIGS
AND LOCALLY/BRIEF MVFR VSBYS APPEAR POSSIBLE IN -SHRA DURING THE
THU-FRI TIME FRAME. IMPROVED AVIATION CONDITIONS ARE EXPECTED BY
SAT/SUN.

&&

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

&&

$$
SYNOPSIS...RAB
NEAR TERM...RAB
SHORT TERM...KK/NF
LONG TERM...WP
AVIATION...RAB


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