Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 311943
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
343 PM EDT MON AUG 31 2015

.SYNOPSIS...
AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL STRENGTHEN OVER THE
APPALACHIANS AND CENTRAL MID ATLANTIC REGION...KEEPING US IN A
RATHER STAGNANT PATTERN WITH A CHANCE FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS THROUGH THE MIDDLE OF THE WORKWEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 330 PM EDT MONDAY...

THE SHORT WAVE WHICH BROUGHT PRECIPITATION TO THE REGION LAST
NIGHT HAS PULLED OFF TO OUR EAST...ALLOWING THE UPPER LEVEL RIDGE
TO REBUILD AND KEEP US IN A WARM AND MOIST ENVIRONMENT WITH LITTLE
IN THE WAY OF DYNAMIC ENERGY TO FOCUS CONVECTIVE DEVELOPMENT. THUS...
WIDELY SCATTERED SHOWERS THAT HAVE DEVELOPED THIS AFTERNOON WILL
BE FADING BY EARLY TONIGHT WITH THE LOSS OF DAYTIME HEATING.
SATELLITE IMAGES SHOW THAT MID AND HIGH CLOUDS WHICH HAVE BEEN
OVER THE REGION FOR THE PAST SEVERAL DAYS HAVE DIMINISHED WHICH
SHOULD ALLOW FOR GOOD COOLING OVERNIGHT. COMBINED WITH A MOIST
AIRMASS IN PLACE WE CAN EXPECT AREAS OF FOG TO DEVELOP TOWARD
DAYBREAK...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE. LOW
TEMPERATURES WILL RANGE FROM THE MIDDLE 60S ACROSS THE PIEDMONT TO
AROUND 60 WEST OF THE RIDGE.

ANY FOG AND LOW CLOUDS WILL DISSIPATE AFTER DAYBREAK ON TUESDAY
AND MORE DIURNAL SHOWERS/POSSIBLY A RUMBLE OF THUNDER WILL DEVELOP
DURING THE AFTERNOON...MAINLY FROM THE BLUE RIDGE WEST WHERE
OROGRAPHIC EFFECTS CAN INITIATE CONVECTION. EVEN WITH PRECIPITABLE
WATER VALUES WELL OVER ONE INCH IT WILL BE HARD TO GENERATE ANY
HEAVY DOWNPOURS DUE TO THE LACK OF INSTABILITY AND DYNAMIC
SUPPORT. HIGH TEMPERATURES TOMORROW WILL BE NEAR 90 DEGREES EAST
OF THE RIDGE AND GENERALLY IN THE LOW/MID 80S WEST.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 330 PM EDT MONDAY...

MODELS WERE CONSISTENT SHOWING A SHORT WAVE OVER THE OHIO VALLEY
TRACKING THROUGH THE MID ATLANTIC STATES ON WEDNESDAY. THIS FEATURES
WILL HELP RE-ENFORCE A SURFACE COASTAL TROUGH THAT WILL EXTEND FROM
NEW JERSEY TO EASTERN NORTH CAROLINA ON WEDNESDAY NIGHT. BEHIND THIS
SHORT WAVE ON WEDNESDAY NIGHT AND THURSDAY 850 WINDS INCREASE TO
AROUND 15 KNOTS FROM THE NORTH-NORTHWEST. WITH THE LACK OF ANY
FORCING ON THURSDAY...BEST PROBABILITY OF PRECIPITATION WITH RETURN
BACK TO THE TYPICAL AFTERNOON AND EVENING TERRAIN ENHANCED LOW
CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LITTLE TO NO CHANGE IN
THE AIR MASS IS EXPECTED THROUGH THE PERIOD. DEW POINTS WILL BE WELL
INTO 60S FOR MOST LOCATIONS WHICH WILL KEEP LOWS MILD. HIGH
TEMPERATURES WILL BE AT OR SLIGHTLY ABOVE NORMAL AND...AS
ALWAYS...WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF CLOUD COVER.
GUIDANCE WAS REASONABLE FOR HIGHS AND LOWS THROUGH THE PERIOD.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 330 PM EDT MONDAY...

WARMER AIR ASSOCIATED WITH THE UPPER RIDGE EVENTUALLY PROGRESSES
EAST INTO THE FORECAST AREA FOR FRIDAY AND SATURDAY. SURFACE HIGH
PRESSURE WILL BE CENTERED OVER PENNSYLVANIA AND NEW YORK AND WILL
WEDGE DOWN THE APPALACHIANS...PRODUCING EAST TO SOUTHEAST WINDS FROM
THE SURFACE THROUGH AT LEAST 850 MB. SO DESPITE THE HIGHER HEIGHTS
ALOFT...LOW LEVEL UPSLOPE CLOUD COVER WILL LIMIT HIGH TEMPERATURES
OVER THE WEEKEND. ECMWF IS SUGGESTING SOME DRIER LOW LEVEL AIR MAY
GET INTO THE EASTERN COUNTY WARNING AREA LATE SUNDAY.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 330 PM EDT MONDAY...

VARIABLE CONDITIONS AT TAF SITES THROUGH THIS FORECAST PERIOD.
SATELLITE IMAGES ARE SHOWING A MAINLY VFR CU FIELD DEVELOP ACROSS
THE REGION...WITH THE EXCEPTIONS BEING ACROSS THE PIEDMONT WHERE
BETTER BETTER LOW LEVEL MOISTURE IS LEADING TO MVFR CIGS. THUS
WILL KEEP FLIGHT CATEGORIES VFR INCLUDING AT KDAN WHERE MVFR CIGS
HAVE MIXED OUT.

RADAR SHOWS SOME DIURNAL CONVECTION FORMING MAINLY ACROSS THE
FAR WESTERN SLOPES OF THE APPALACHIANS IN WHAT CONTINUES TO BE A
STAGNANT AND WEAKLY FORCED PATTERN. EXPECT SCATTERED SHOWERS AND A
FEW RUMBLES OF THUNDER TO BUBBLE UP MAINLY WEST OF THE BLUE RIDGE
BEFORE FADING THE LOSS OF HEATING AFTER SUNSET. WILL GENERALLY USE
VCSH TO COVER THIS ACTIVITY EXCEPT AT KLWB WHERE PREDOMINANT -SHRA
WILL BE MORE REPRESENTATIVE WHERE THE ACTIVITY IS MORE
CONCENTRATED.

BELIEVE CLOUDS WILL SCATTER OUT EARLY TONIGHT AND WITH MODEL
SOUNDINGS CONTINUING TO SHOW A MOIST PROFILE AT ALL SITES...FOG
AND STRATUS FORMATION SEEMS LIKE A GOOD BET. LOOK FOR IFR VSBYS AT
KBLF AND LIFR CONDITIONS AT KLWB AND KBCB BEFORE DAYBREAK. KLYH
SHOULD REMAIN MVFR AND EXPECT IFR CIGS/VSBYS AT KDAN.

FOG/STRATUS WILL LIFT AFTER SUNRISE TUESDAY SO EXPECT VFR CONDITIONS
TOWARD THE END OF THE TAF PERIOD WITH THE NEXT ROUND OF DIURNAL
CONVECTION HOLDING OFF UNTIL TUESDAY AFTERNOON.

EXTENDED AVIATION DISCUSSION...

THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH MIDWEEK...WITH CHANCES FOR DIURNAL CONVECTION
MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR FOG/STRATUS
DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB.

&&

.EQUIPMENT...
AS OF 400 AM EDT MONDAY...

THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.

&&

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

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...MBS/NF
EQUIPMENT...CF



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