Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 310225
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1025 PM EDT THU JUL 30 2015

.SYNOPSIS...
A COLD FRONT WILL SLIDE EAST OF OUR REGION TONIGHT...STALLING
ALONG THE SOUTHEAST COAST FRIDAY INTO SATURDAY. THIS WILL ALLOW
FOR HIGH PRESSURE TO KEEP MOST OF THE AREA DRY THROUGH THE
WEEKEND...AS IT MOVES IN FROM THE WEST.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1020 PM EDT THURSDAY...

DRIER AIR WILL BE OVERSPREADING MUCH OF OUR COUNTY WARNING AREA
TONIGHT BEHIND A COLD FRONT THAT WAS MOVING THROUGH THE FAR
EASTERN PART OF THE FORECAST AREA THIS EVENING. THE FRONT SLOWS
DOWN TO THE EAST AND KEEPS THE HIGHER DEWPOINTS LINGERING LONGER
OVER THE PIEDMONT. SHOWERS AND THUNDERSTORMS WILL MOVE OUT OF THE
PIEDMONT BY MIDNIGHT...WITH SKIES CLEARING. LIGHT WINDS AND COOLER
AIR MAY RESULTS IN SOME PATCHY FOG ALONG THE RIVERS EARLY FRIDAY
MORNING.

HIGH PRESSURE BUILDS EAST FROM THE CENTRAL PLAINS FRIDAY. THE
HIGH CENTER WILL BRING WITH IT DRIER AIR...PUSHING DEWPOINTS INTO
THE 50S AND LOWER 60S. THE LOWER RELATIVE HUMIDITIES WILL BE A
WELCOME CHANGE FOR MANY. HIGH TEMPERATURES FRIDAY AFTERNOON WILL
BE IN THE MID 70S IN THE NORTHWEST MOUNTAINS TO AROUND 90 DEGREES
IN THE PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 215 PM EDT THURSDAY...

A QUIET AND RATHER COMFORTABLE PERIOD LOOKS IN STORE UNDER BROAD UPPER
TROFFINESS ENHANCED VIA SURFACE HIGH PRESSURE BUILDING OVERHEAD THROUGH
THE WEEKEND. THIS SHOULD RESULT IN MAINLY SUNNY WARM DAYS AND
CLEAR/PLEASANT NIGHTS GIVEN DRIER DEWPOINTS AND SUBSEQUENT LOWER
HUMIDITY THROUGH AT LEAST SUNDAY. ONLY EXCEPTIONS COULD BE WITH MORE
CLOUDS AND POSSIBLY A FEW LIGHT SHOWERS NW UNDER SLIGHTLY BETTER
UPSLOPE LATE SATURDAY...AND THEN PERHAPS OVER THE WESTERN HALF SUNDAY
EVENING WITH A PASSING MID LEVEL SHORTWAVE. HOWEVER GIVEN PROGGED
DRYNESS AND LIKELY ISOLATED NATURE TO ANY SHOWERS OPTING TO LEAVE OUT
ANY POPS OR SHOWER MENTION FOR NOW.

TEMPS LOOK TO REMAIN QUITE PERSISTENT THROUGH THE PERIOD WITH WEAK
DOWNSLOPE/HEATING OF DRY AIR ALLOWING HIGHS TO REMAIN IN THE 85-90
RANGE EAST...AND MOSTLY LOW/MID 80S MOUNTAINS DESPITE THE COOLER/DRIER
AIRMASS. BETTER IMPACT OF THE DRY AIR TO BE FELT DURING THE OVERNIGHTS
WITH LOWS IN THE 50S VALLEYS AND LOW/MID 60S ELSEWHERE. COOLEST NIGHT
AT THIS POINT LOOKS TO BE EARLY SUNDAY WITH THE PASSING OF THE 85H
TROUGH...AND HIGH PRESSURE ABOUT OVERHEAD POSSIBLY ALLOWING A FEW 40S
IN THE DEEPEST NW VALLEYS PENDING ANY RIVER FOG LATE.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 1230 PM EDT THURSDAY...

MEAN 5H TROUGH TO REMAIN ACROSS THE MID ATLANTIC REGION THROUGH MUCH OF
NEXT WEEK WITH STEADY NW FLOW ALOFT BETWEEN UPPER LEVEL LOW PRESSURE
WELL TO THE NORTH AND STRONG RIDGING OVER THE SW STATES. THIS SHOULD
ALLOW FOR AN OVERALL PERSISTENCE TYPE FORECAST THROUGH THE EXTENDED
WITH TOLERANT HUMIDITY LEVELS ALONG WITH LOWS MOSTLY IN THE 60S AND
HIGHS 80S TO LOWER 90S. COVERAGE OF SHOWERS AND STORMS ALSO LIKELY
LIMITED PENDING PROGRESSION OF THE NEXT POSSIBLE COOL SURGE LATE IN THE
PERIOD. HOWEVER WILL ALSO HAVE TO WATCH LINGERING MOISTURE WITH THE
RESIDUAL FRONT NEAR THE COAST WHICH COULD BE LIFTED BACK NORTH BY
APPROACH OF WEAK IMPULSES ALOFT ESPECIALLY EARLY NEXT WEEK. THIS ALONG
WITH HEATING MAY BE ENOUGH TO SPARK ISOLATED CONVECTION MAINLY SOUTH
MONDAY...AND ALONG A PASSING SHORTWAVE TROUGH AXIS CROSSING FROM THE NW
TUESDAY...BUT LOW POPS AT BEST BOTH DAYS.

UPPER TROUGH JUST NORTH OF THE LAKES WILL DEEPEN AGAIN BY MIDWEEK AS
MORE SHORTWAVE ENERGY ROTATES THROUGH AND SLIDES AN ASSOCIATED COLD
FRONT SOUTH TOWARD/INTO THE REGION. HOWEVER MODELS DISAGREE ON THE
AMPLITUDE OF THE DIGGING TROUGH WITH THE GFS MOST AGGRESSIVE WHILE
OTHER SOLUTIONS SLOWER/WEAKER WHILE MAINTAINING MORE CONVECTION ALONG
THE BOUNDARY. FOR NOW WILL GO WITH A WEAKER/SLOWER SCENARIO BUT LEAN
TOWARD THE GFS IN DRIVING THE COOL ADVECTION IN BY THE END OF THE
PERIOD SINCE IT HAS BEEN BEST OF LATE.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 740 PM EDT THURSDAY...

A COLD FRONT WILL CONTINUE TO MOVE EAST ACROSS THE REGION THIS
EVENING. ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG
THE FRONT. RADAR SHOWED A STORM UPSTREAM OF KDAN AND AT CURRENT
SPEED AND DIRECTION...THIS FEATURE WILL REACH THE AIRPORT AROUND
01Z. NO CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE OTHER LOCAL
TAF SITES...WHICH WERE BEHIND THE FRONT.

WITH DRIER AIR WORKING IN TONIGHT AND SURFACE DEW POINTS LOWERING
INTO THE LOWER 50S TO LOWER 60S...THE FOG THREAT SHOULD BE
MINIMIZED...THOUGH THERE IS A SMALL CHANCE THAT LWB/BCB COULD FOG
IN GIVEN SOME SLIGHTLY COOLER AIR OVER THE NEW AND GREENBRIER
RIVERS.

VFR CONDITIONS EXPECTED FRIDAY. HIGH CONFIDENCE IN CEILINGS...VISIBILITIES
AND WINDS DURING THE PERIOD.

EXTENDED AVIATION FORECAST...

UNDER HIGH PRESSURE...DRY AND VFR FRIDAY NIGHT THROUGH SUNDAY.
THE NEXT CHANCE OF MVFR CONDITIONS WILL BE ON MONDAY AND TUESDAY
AS MOISTURE AND A LOW PROBABILITY OF SHOWERS AND THUNDERSTORMS
RETURN TO THE REGION.

&&

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

&&

$$
SYNOPSIS...AMS/KK
NEAR TERM...AMS/KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...AMS/KK


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