Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 251738
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
138 PM 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 1250 PM EDT MONDAY...

NO MAJOR CHANGES TO THE FORECAST THE REMAINDER OF TODAY AND INTO
THE EARLY EVENING HOURS. CLOUD COVER WILL BE THE MOST ABUNDANT THE
NEXT COUPLE OF HOURS WHERE IT IS CURRENTLY ONGOING...ONE TIER OF
COUNTIES EITHER SIDE THE CREST OF THE BLUE RIDGE. AS DAYTIME
HEATING CONTINUES...CLOUD COVER WILL CONTINUE TO EXPAND IN
COVERAGE...ESPECIALLY WESTWARD OF THE CURRENT CONCENTRATION. A
SMALL OPPORTUNITY WILL EXIST FOR THE DEVELOPMENT OF FIRST ISOLATED
SHOWERS ACROSS PARTS OF THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...NORTHWARD INTO SOUTHWEST SECTIONS OF THE MOUNTAIN
EMPIRE REGION OF SOUTHWEST VIRGINIA. AN ISOLATED THUNDERSTORM OR
TWO WILL ALSO BE POSSIBLE IN THIS REGION HEADING INTO THE EVENING
HOURS. HAVE LOWERED EXPECTED HIGH TEMPERATURES BY A COUPLE OF
DEGREES WITHIN THE REGION WHERE CLOUD COVER CURRENTLY THE MOST
ABUNDANT.

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 /18Z MONDAY THROUGH SATURDAY/...
AS OF 125 PM EDT MONDAY...

VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF THE
AFTERNOON INTO THE THE FIRST HALF OF THE OVERNIGHT HOURS. ISOLATED
SHOWERS OR THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON INTO THE
EARLY EVENING ALONG AND WEST OF A KBLF-KUKF LINE.

LATE TONIGHT INTO TUESDAY MORNING...INCREASING LOW LEVEL MOISTURE
WILL BECOME TRAPPED UNDER THE NOCTURNAL INVERSION AND YIELD
IFR/MVFR CIGS AND PATCHY MVFR LIGHT FOG. ONCE THE INVERSION BREAKS
BY LATE MORNING...LOOK FOR AN IMPROVEMENT TO LOW END VFR CIGS
THROUGH MID-DAY. ISOLATED SHOWERS WILL CONTINUE TO BE A POTENTIAL
ACROSS THE WESTERN QUARTER OF THE FORECAST REGION LATE TONIGHT
INTO TUESDAY MORNING.

EXTENDED AVIATION DISCUSSION...

AN UPPER LEVEL TROUGH ACROSS THE CENTRAL PORTION OF THE COUNTRY
WILL MAKE STEADY PROGRESS EASTWARD DURING THE WEEK...AND TRY TO
SQUELCH THE INFLUENCE OF THE UPPER RIDGE PARKED OVER THE EAST
COAST OF THE U.S. THIS WILL ALLOW FOR AN INCREASING OPPORTUNITY
FOR SHOWERS AND STORMS ACROSS THE AREA...WITH THE FOCUS FOR THE
BEST COVERAGE REMAINING ACROSS THE WESTERN PORTIONS OF THE
FORECAST AREA.

CHANCES WILL INCREASE THROUGH THURSDAY. FRIDAY INTO
SATURDAY...TROUGHINESS REFOCUSES ACROSS THE CENTRAL PART OF THE
COUNTRY AND THE UPPER RIDGE IN THE EAST REINTENSIFIES OVER THE
EAST COAST. THIS WILL RETURN OUR PATTERN TO ONE OF MORE HEAT AND
HUMIDITY WITH DIURNALLY FIRED SHOWERS AND STORMS IN THE WEST...AS
COMPARED TO THE ONES WITH MORE UPPER LEVEL DYNAMICS INVOLVED MID-
WEEK.

&&

.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...DS


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