Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS61 KRNK 251402
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1002 AM EDT MON MAY 25 2015

.SYNOPSIS...
HIGH PRESSURE BOTH SURFACE AND ALOFT WILL REMAIN OVER THE EASTERN
UNITED STATES TODAY. THIS WILL ENSURE DRY WEATHER FOR THE
REMAINDER OF THE HOLIDAY WEEKEND WITH TEMPERATURE AND HUMIDITY
TRENDING HIGHER. DEEPER MOISTURE WILL RETURN TO THE AREA BY
TUESDAY...WITH SHOWERS AND THUNDERSTORMS DEVELOPING TUESDAY...
BECOMING MORE WIDESPREAD ACROSS THE REGION WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EDT MONDAY...

NO MAJOR CHANGES TO THE OVERALL FORECAST FOR TODAY. IN THE NEAR
TERM...HAVE MADE SOME ADJUSTMENTS TO THE SKY COVER GRIDS FOR THE
NEXT FEW HOURS ALONG THE CREST OF THE BLUE RIDGE ALONG AND
SOUTHWEST OF ROUGHLY ROANOKE. LOW LEVEL MOISTURE WAS BEING
CHANNELED WITHIN THIS AREA...AND A REGION OF CUMULUS AND STATRO-
CUMULUS THAT HAS BEEN IN THIS AREA SINCE JUST BEFORE DAYBREAK...IS
FILLING IN A BIT MORE QUICKLY THAN PREVIOUSLY ADVERTISED. AS THE
DAY CONTINUES TO WARM...THIS REGION IS EXPECTED TO MIX OUT AND WE
WILL START SEEING HIGHER BASED CLOUD DEVELOPMENT BY THIS
AFTERNOON. HAVE ALSO TWEAKED THE LATEST TEMPERATURE...DEW POINT
AND WIND SPEED GRIDS TO REFLECT THE LATEST OBSERVATIONS...AND
EXPECTED TRENDS INTO THE EARLY AFTERNOON.

AS OF 500 AM EDT MONDAY...

SOUTHERLY WINDS ON WESTERN PERIPHERY OF DEPARTING ANTICYCLONE
WILL GRADUALLY ADVECT LOW LEVEL MOISTURE NORTHWARD INTO THE
MOUNTAINS OF NORTH CAROLINA AND FAR SOUTHWEST VIRGINIA TODAY.
THIS WILL PERMIT INCREASING CLOUDINESS OVER OUR FAR SOUTHWEST CWA
TODAY WITH THE POTENTIAL FOR LATE AFTERNOON AND EVENING SHOWERS
WEST OF INTERSTATE 77. THE REMAINDER OF THE CWA WILL CONTINUE TO
BASK IN SUNSHINE PER LINGERING SUBSIDENCE. TEMPERATURES THIS
AFTERNOON ARE EXPECTED TO REACH INTO THE 80S...WITH THE EXCEPTION
OF THE NC MTNS AND HIGHLANDS OF VA/WV WHERE TEMPERATURES WILL TOP
OUT IN THE 70S.

DEEPER MOISTURE WILL OVERSPREAD THE REMAINDER OF THE REGION
TONIGHT INTO TUESDAY...CLOUDS INCREASING. DEWPOINTS WILL BE
TRENDING UP...PROMOTING HIGHER HUMIDITY AND HIGHER NIGHT-TIME
TEMPERATURES.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 400 AM EDT MONDAY...

LOOKING AT A VERY SUMMERLIKE WEATHER PATTERN FOR THE MIDDLE OF THE
WEEK AS THE UPPER LEVEL RIDGE WHICH MADE FOR ABUNDANT SUNSHINE THIS
WEEKEND SHIFTS EAST...LEAVING THE MID ATLANTIC EXPOSED TO A SERIES
OF UPPER LEVEL DISTURBANCES APPROACHING FROM THE LOWER MISSISSIPPI
VALLEY. SOUTHERLY WINDFLOW IN THE LOW LEVELS WILL ALSO BE FIRMLY
ESTABLISHED BY TUESDAY...RETURNING DEEP GULF MOISTURE NORTHWARD
ALONG THE APPALACHIAN CHAIN...WHICH WILL PUSH PERCEPTIBLE WATER
VALUES IN THE 1.3 TO 1.6 INCH RANGE FOR MUCH OF THE PERIOD. SUCH
MOISTURE WILL PROVIDE THE FUEL NECESSARY...WHEN INTERACTING WITH
THE UPPER LEVEL DISTURBANCES...TO TRIGGER SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY.

ON TUESDAY...WILL KEEP AN EYE ON AN INVERTED TROUGH PASSING JUST
WEST OF OUR AREA WHICH WILL SUPPORT SHOWERS AND THUNDERSTORMS...MORE
SO FOR THE MOUNTAINS DURING THE AFTERNOON...WITH SOME OF THIS
ACTIVITY SPILLING INTO THE PIEDMONT DURING THE EVENING. ON
WEDNESDAY...AN UPPER LEVEL TROUGH WILL SHIFT EAST ACROSS THE GREAT
LAKES...PUSHING AN ASSOCIATED WEAK COLD FRONT TOWARD THE OHIO RIVER
WHERE IT WILL EVENTUALLY STALL. THE INCREASED LOW LEVEL CONVERGENCE
AHEAD OF THE FRONT AND GREATER INSTABILITY ALOFT WILL ALLOW FOR MORE
WIDESPREAD COVERAGE OF CONVECTION. ANOTHER UPPER LEVEL RIDGE IS
EXPECTED TO DEVELOP THURSDAY AS A TROUGH DIGS ACROSS THE
INTERMOUNTAIN WEST. INCREASED STABILITY ALOFT COMBINED WITH WINDS
BECOMING MORE WESTERLY/DOWNSLOPE WILL KEEP SHOWER AND THUNDERSTORM
ACTIVITY A LITTLE LESS DEVELOPED/MORE SPOTTY IN NATURE.

DO NOT SEE ANY STRONG SIGNALS FOR ORGANIZED SEVERE THUNDERSTORM
ACTIVITY DURING THE PERIOD...HOWEVER CANNOT RULE OUT A FEW STRONG TO
SEVERE STORMS DEVELOPING DURING EACH AFTERNOON AND EVENING AREAWIDE.
ALSO...WITH A VERY MOIST ATMOSPHERE AND UPPER LEVEL WINDS EXPECTED
TO BECOME LIGHT BY THE MIDDLE OF THE WEEK...WILL HAVE TO WATCH FOR
AREAS OF HEAVY RAIN DUE TO SLOW MOVING STORMS...WHICH MAY PRODUCE
LOCALIZED FLASH FLOODING.

STUCK CLOSE TO MAV GUIDANCE FOR TEMPERATURES...WHICH ARE EXPECTED TO
RANGE FROM THE UPPER 70S/LOW 80S ACROSS THE MOUNTAINS...TO THE MID
80S FURTHER EAST EACH DAY. OVERNIGHT TEMPERATURES WILL RANGE FROM
THE UPPER 50S/LOW 60S WEST...TO THE MID 60S EAST.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 445 AM EDT MONDAY...

A VERY WARM AND MUGGY PERIOD MORE REMINISCENT OF SUMMER LOOKS TO
PREVAIL FOR LATE WEEK INTO NEXT WEEKEND AS A MOIST SOUTH/SW FLOW
PERSISTS BETWEEN HIGH PRESSURE OFFSHORE AND UPPER TROFFINESS TO THE
NW. THIS...PROVIDED STRONG HEATING...SHOULD RESULT IN AT LEAST
DIURNAL SHOWERS AND STORMS ESPCLY OVER THE MOUNTAINS WHERE AIDED BY
OROGRAPHICS AND DIFFERENTIAL HEATING.

UPPER HEIGHTS WILL SLOWLY FLATTEN NEXT WEEKEND AS ANOTHER 5H TROUGH
STARTS TO SINK SOUTH FROM THE UPPER MIDWEST WITH ITS ASSOCIATED COLD
FRONT LIKELY OOZING TOWARD THE AREA BY SUNDAY. MODELS DIFFER ON HOW
FAST THIS BOUNDARY PUSHES SE WITH THE EARLIER EC MORE HUNG UP TO THE
NW PER WAVES ALONG THE FRONT...WHILE THE GFS MORE BACKDOOR FASHION
AND FASTER. HOWEVER APPEARS THAT THE BOUNDARY WILL BE CLOSE ENOUGH
TO PRODUCE MORE WIDESPREAD SHOWERS/STORMS SUNDAY AFTERNOON ESPCLY
NORTHERN/WESTERN SECTIONS...WITH MORE SCATTERING SATURDAY OUTSIDE OF
THE NW WHERE MORE ORGANIZED PRE-FRONTAL BANDS COULD DROP IN LATE.

OTHERWISE OVERALL TREND OF EARLY FOG TO BECOMING PC DURING THE DAY
WITH MORE CLOUDS BY SUNDAY...AND DIURNAL CHANCE POPS...EXCEPT SOME
LIKELY POPS WEST LATER IN THE WEEKEND. EXPECT TEMPS TO SLOWLY CLIMB
EACH DAY WITH HIGHS POSSIBLY TOUCHING 90 OUT EAST OVER THE WEEKEND
WITH MAINLY 80S ELSEWHERE. LOWS LOOK QUITE WARM AND MUGGY..ONLY IN
THE 60S AT BEST GIVEN MOISTURE AROUND.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 230 AM EDT MONDAY...

VFR EXPECTED TO CONTINUE THROUGH THE TAF VALID PERIOD...ALTHOUGH
SOME SUBTLE SIGNS OF BIGGER CHANGES TO TAKE PLACE THROUGH THE
WEEK...WILL BECOME EVIDENT THIS TAF VALID PERIOD. THE UPPER RIDGE
CENTERED OVER THE REGION WILL CONTINUE TO DRIFT SLOWLY EAST
THROUGH TODAY...MOVING TOWARD THE COAST BY TUESDAY. A BROAD
DIFFLUENT UPPER TROUGH ENCOMPASSES MUCH OF THE U.S. WEST OF THE
MISSISSIPPI RIVER...AND THIS WILL BE EXPANDING FARTHER EAST
THROUGH THE MID PART OF THE WEEK. A SERIES OF UPPER SHORT WAVES
WILL TRACK FROM THE MID-SOUTH TO THE NORTHEAST MON-WED...EACH
BREAKING DOWN THE UPPER RIDGE AND FORCING IT TO SHIFT FARTHER
EAST. LOW-LEVEL MOISTURE WILL BE ON THE INCREASE WITH SOUTHWEST
FLOW AROUND A BERMUDA HIGH. THIS WILL RESULT IN INCREASING CU
DEVELOPMENT IN THE 040-060 RANGE MON AFTERNOON WITH PERIODS OF BKN
CLOUD BASES POSSIBLE DURING THE AFTERNOON...ESPECIALLY WEST OF
THE BLUE RIDGE...BUT FEEL THAT THE POTENTIAL FOR SHRA/TSRA WILL
REMAIN WEST OF THE CWA TODAY.

WINDS TODAY WILL BECOME SSW-SW AFT 13Z MON WITH SPEEDS 7-10KTS
AND LOW END GUSTS LIKELY AT BLF/ROA/BCB BY LATE MORNING THROUGH
THE AFTERNOON.

MEDIUM TO HIGH CONFIDENCE IN CEILINGS THROUGH THE TAF VALID
PERIOD. MEDIUM TO HIGH CONFIDENCE IN VISIBILITIES THROUGH THE TAF
VALID PERIOD. MEDIUM TO HIGH CONFIDENCE WIND SPEED/DIRECTION
THROUGH THE TAF VALID PERIOD.

EXTENDED AVIATION DISCUSSION...

SOUTH-SOUTHWEST WINDS WILL CONTINUE TO BRING INCREASING MOISTURE
LEVELS INTO THE REGION...ESPECIALLY WEST OF THE BLUE RIDGE TUESDAY.
MEANWHILE...THE UPPER-LEVEL WILL BECOME INCREASINGLY FAVORABLE FOR
SHOWERS/THUNDERSTORMS AS DISTURBANCES EMANATE FROM A BROAD UPPER
TROUGH ACROSS THE CENTRAL/WESTERN U.S. EXPECT SCATTERED
SHOWERS/THUNDERSTORMS MAINLY THROUGH THE I-77 CORRIDOR TUESDAY
AFTERNOON...SPREADING FARTHER EAST ACROSS MUCH OF THE CWA
WEDNESDAY THROUGH THE END OF THE WEEK. WED-THU AT THIS POINT
APPEAR TO BE THE MOST ACTIVE DAYS FOR THUNDERSTORMS...WITH SOME
STRONG THUNDERSTORMS AND HEAVY RAIN POSSIBLE DURING THIS TIME
FRAME. THE THREAT FOR SHOWERS/THUNDERSTORMS MAY WELL LINGER FOR
SEVERAL SUBSEQUENT DAYS AS A WEAK FRONTAL BOUNDARY/BAROCLINIC ZONE
STALL ACROSS THE REGION WITH ADDITIONAL UPSTREAM ENERGY REMAINING
IN PLACE.

ASIDE FROM SHOWERS/THUNDERSTORMS...CONDITIONS SHOULD GENERALLY BE
VFR OR MVFR AT WORST...BUT INCREASING LIKELIHOOD OF EARLY MORNING
IFR-LIFR CONDITIONS IN BR/FG AND LOW CLOUDS AS MOISTURE LEVELS
INCREASE AND LATE DAY SHOWERS LEAVE WET GROUND IN PLACE.

&&

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

&&

$$
SYNOPSIS...JH/PM
NEAR TERM...DS/PM
SHORT TERM...NF
LONG TERM...JH/NF
AVIATION...PM



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.