Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 010517
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
117 AM EDT TUE SEP 1 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 TODAY/...
AS OF 1000 PM EDT MONDAY...

SHOWERS ARE GONE...AND WILL SEE MORE CLEARING THAN PREVIOUSLY
FORECAST...SO CUT BACK ON CLOUD COVER. WILL SEE A SETUP FOR FOG TO
FORM IN THE VALLEYS AND ACROSS PORTIONS OF THE PIEDMONT...AND KEPT
IN THE GRIDS. NO OTHER MAJOR CHANGES WERE MADE TO THE FORECAST.

PREVIOUS VALID DISCUSSION...

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 /TONIGHT 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 /06Z TUESDAY THROUGH SATURDAY/...
AS OF 100 AM EDT TUESDAY...

SKIES MAINLY CLEAR ACROSS THE REGION TONIGHT WITH PATCHY FOG
STARTING TO DEVELOP IN THE LOW SPOTS/VALLEYS WITH STRATUS JUST
EAST OF THE REGION IN SPOTS CLOSER TO THE COAST. LATEST MODELS
SUGGEST MUCH OF THE STRATUS TO STAY TO THE EAST WHILE STILL
EXPECTING SOME DEVELOPMENT OF FOG IN THE VALLEYS ALONG WITH AREAS
OF STRATUS. THUS KEEPING THE GOING SCENARIO OF SEEING LIFR/IFR AT
KBCB/KLWB BY DAYBREAK AND SPOTTY MVFR TO IFR AT TIMES ACROSS THE
EAST.

FOG/STRATUS WILL LIFT AFTER SUNRISE TUESDAY SO EXPECT VFR CONDITIONS
TO TAKE SHAPE BY MID/LATE MORNING WITH THE NEXT ROUND OF DIURNAL
CONVECTION HOLDING OFF UNTIL TUESDAY AFTERNOON. THUS KEPT VCSH AT
KBLF/KLWB WITH BKN VFR CIGS AT 4-6KFT. MAY SEE SOME BROKEN VFR
CIGS ELSEWHERE ALONG THE BLUE RIDGE BUT KEEPING LOCATIONS AROUND
KBCB/KROA DRY FOR NOW.

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.

FOR FRIDAY INTO SATURDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS.

&&

.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/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JH/MBS/NF/WP
EQUIPMENT...



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