Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 281409
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1009 AM EDT MON JUL 28 2014

.SYNOPSIS...
COOLER DRIER CANADIAN AIR WILL MOVE INTO THE MID ATLANTIC BEHIND A
COLD FRONT TODAY. AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE
GREAT LAKES WILL BRING GUSTY WINDS TO THE FORECAST REGION LATE
THIS MORNING AND THIS AFTERNOON...IN ADDITION TO SPOTTY UPSLOPE
SHOWERS ALONG THE WESTERN RIDGES. COOLER CONDITIONS WILL REMAIN
ACROSS THE AREA THROUGH MUCH OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT MONDAY...

HAVE MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST THIS MORNING.
HAVE REMOVED ISOLATED TO SCATTERED SHOWERS ACROSS THE WESTERN PART
OF THE AREA FOR ABOUT THEN NEXT 2 TO 3 HOURS. EXPECTING MORE OF A
NOON TO 100 PM INITIATION TIME FOR ANY SHOWER ACTIVITY IN THIS
REGION. CURRENT COVERAGE HAS WANED TO ONLY A FEW SPRINKLES OVER
WESTERN GREENBRIER COUNTY WV. HAVE ALSO ADJUSTED TEMPERATURE AND
DEW POINT TO REFLECT THE LATEST OBSERVATIONS AND EXPECTED TRENDS
INTO THE EARLY AFTERNOON.

AS OF 400 AM EDT MONDAY...

ASIDE FROM A FEW SPRINKLES LEFT OVER ACROSS THE MOUNTAINS THIS
MORNING...ALL SHOWER ACTIVITY HAS EXITED THE AREA FOR THE TIME
BEING. THE COLD FRONT CONTINUES TO MAKE STEADY PROGRESS ACROSS
WEST VIRGINIA AS THE PARENT SURFACE LOW SHIFTS EAST OVER EASTERN
PENNSYLVANIA...AND EXPECT THE COLD FRONT TO ENTER OUR SOUTHEAST
WEST VIRGINIA COUNTIES BY AROUND SUNRISE...PUSHING RAPIDLY EAST
THROUGH THE MORNING.

THE MAIN CONCERN FOR THE MORNING WILL BE GUSTY WINDS ACROSS THE
MOUNTAINS BEHIND THE FRONT AS A DEEP UPPER LEVEL DISTURBANCE
PASSES ACROSS THE EASTERN GREAT LAKES. STRONG WINDS WRAPPING
AROUND THE SOUTHERN END OF THE DISTURBANCE WILL PUSH ACROSS THE
MOUNTAINS DURING LATE MORNING AND EARLY AFTERNOON...AND EXPECT
GUSTS TO MAX OUT AS HIGH AS 40 MPH AT TIMES AT ELEVATIONS OF 30OO
FEET AND UP. THE MAIN ENERGY MOVING AROUND THE UPPER DISTURBANCE
WILL SHIFT EAST OF THE AREA DURING MID AFTERNOON...AND EXPECT TO
SEE WIND SPEEDS GRADUALLY DIMINISH THEREAFTER.

WITH WINDS SHIFTING NORTHWESTERLY AROUND THE BACKSIDE OF THE
DISTURBANCE DURING EARLY AFTERNOON...WILL ALSO SEE SPOTTY UPSLOPE
SHOWER ACTIVITY DEVELOP ACROSS OUR WESTERN RIDGELINES OF SOUTHEAST
WEST VIRGINIA INTO THE NORTH CAROLINA MOUNTAINS. LAPSE RATES WILL
BECOME STEEP ENOUGH FOR A FEW HOURS DURING THE AFTERNOON THAT
WOULD NOT BE SURPRISED TO SEE A FEW SHOWERS DEVELOP INTO
THUNDERSTORMS...BUT BELIEVE THOSE WILL BE FEW AND FAR IN BETWEEN
AT BEST. SHOWER ACTIVITY WILL DECREASE INTO THE EVENING AS WIND
SPEEDS CONTINUE TO DIMINISH...BUT EXPECT A FEW SHOWERS TO LINGER
INTO EARLY TUESDAY.

TEMPERATURES WILL BE COOLER ACROSS THE MOUNTAINS TODAY ONCE THE
FRONT PASSES...HOWEVER THERE WILL BE TIME FOR DECENT HEATING
BEFORE THE FRONT ARRIVES ACROSS THE PIEDMONT CONSIDERING THE
DECREASING CLOUD COVER AND DRY DOWNSLOPE WESTERLY WINDS. EXPECT
HIGHS TO RANGE FROM THE LOW 70S ACROSS THE WESTERN RIDGES TO THE
UPPER 80S ACROSS THE SOUTHSIDE. LOWS TONIGHT WILL FALL INTO THE
LOW 50S WEST AND THE LOW 60S EAST.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM EDT MONDAY...

MODELS ARE IN GOOD AGREEMENT THAT A FULL LATITUDE UPPER TROF WILL
COVER THE EASTERN HALF OF THE U.S. DURING THE SHORT TERM
PERIOD...KEEPING TEMPERATURES WELL BELOW AVERAGE FOR LATE JULY.

WITH ONLY A THIN LAYER OF MOISTURE EXPECTED BETWEEN 5-10KT
TUESDAY...PRECIPITATION WILL BE HARD TO COME BY...BUT KEPT A SMALL
CHANCE IN FAR SOUTHWEST VA AND NW NC...AS A WEAK UPPER LEVEL
IMPULSE ROUNDS THE BASE OF THE UPPER TROF. OTHERWISE...ONLY SOME
CUMULUS CLOUDS WILL COVER THE REGION. TUESDAY SHOULD BE THE
COOLEST DAY DURING THIS PERIOD WITH THE GEFS FORECASTING 850MB
TEMPS 2-3 STANDARD DEVIATIONS BELOW NORMAL. MODEL GUIDANCE HAS
BEEN VERY CONSISTENT FROM RUN TO RUN WITH ITS HIGH TEMPERATURE
FORECAST....SO STRAYED LITTLE FROM THE UPPER 60S/LOWER 70S
FORECAST IN THE MOUNTAINS TO UPPER 70S/LOWER 80S EAST OF THE BLUE
RIDGE.

A WEAK LOW THAT FORMS OFF THE CAROLINA COAST TUESDAY LIFTS NORTHEAST
INTO THE ATLANTIC SHOULD REMAIN FAR ENOUGH EAST TO NOT INFLUENCE OUR
WEATHER. SFC HIGH PRESSURE BUILDS INTO THE WESTERN PORTION OF THE
FORECAST AREA BY 12Z (8 AM EDT) WEDNESDAY. GOOD RADIATIONAL COOLING
CONDITIONS SHOULD ALLOW LOW TEMPS TO FALL INTO THE 40S IN SOME
LOCATIONS IN THE MOUNTAINS TO THE MID TO UPPER 50S IN THE EAST.
THESE VALUES WILL BE CLOSE TO THE RECORDS FOR JULY 30TH. SEE CLIMATE
SECTION BELOW FOR RECORD LOWS FOR WEDNESDAY.

UPPER TROF RELAXES SOME ON WEDNESDAY...ALLOWING 850MB TEMPS TO WARM
A COUPLE OF DEGREES VERSUS TUESDAY. STILL...TEMPS WILL BE WELL BELOW
NORMAL. THE 00Z NAM AND 21Z SREF APPEAR BULLISH ON DEVELOPING
UPSLOPE SHOWERS WEDNESDAY AFTERNOON. CONSIDERING THE AMOUNT OF DRY
AIR IN PLACE...KEPT THE FORECAST DRY. SFC HIGH PRESSURE FORECAST TO
SIT OVER THE WESTERN HALF OF THE FORECAST AREA WEDNESDAY
NIGHT...BUT WITH DEW POINTS SLIGHTLY HIGHER...LOWS WILL BE A
DEGREE OR TWO WARMER THURSDAY MORNING...BUT STILL WELL BELOW
NORMAL AND CLOSE TO RECORD LOWS IN SOME LOCATIONS LIKE LWB.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1200 PM EDT SUNDAY...

A SURFACE HIGH THURSDAY OVER SOUTHERN MICHIGAN WILL SHIFT EAST
TOWARDS NEW ENGLAND BY FRIDAY AND SATURDAY. AT THE MID LEVELS A
PERSISTENT TROUGH IS SET UP OVER THE EASTERN US WITH A RIDGE OVER
THE WESTERN US. THURSDAY LACKS LOW AND MID LEVEL MOISTURE SO EXPECT
THE DAY TO BE DRY. MOISTURE AND INSTABILITY INCREASE FOR FRIDAY AND
THROUGH THE REST OF THE PERIOD AS SEVERAL DISTURBANCES PIVOT ACROSS
THE REGION AROUND THE BASE OF THE TROUGH. EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP EACH AFTERNOON/EVENING AND TAPER OFF TO
JUST SCATTERED SHOWERS DURING THE EVENING. FOCUS OF THE HIGHEST
CHANCE POPS ARE OVER THE MOUNTAINS WHERE THE BEST CONVERGENCE WILL
BE LOCATED...WITH LOWER CHANCE POPS OUT EAST.

THURSDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH 850MB TEMPS
AROUND +16C. THIS WILL CORRESPOND TO SURFACE HIGH TEMPS IN THE MID
80S OUT EAST AND NEAR 80 ACROSS THE MOUNTAINS. AS THE HIGH SHIFTS
EAST ON FRIDAY THE WINDS WILL SHIFT FROM N/NW TO AN EASTERLY
DIRECTION. THIS WILL WEDGE THE AREA IN THROUGH THE REMAINDER OF THE
PERIOD. WITH THE INCREASED LOW/MID LEVEL MOISTURE EXPECT CLOUDY
CONDITIONS. THIS ALONG WITH EXPECTED SCATTERED PRECIP AND 850MB
TEMPS FALLING TO +11-14C...SURFACE HIGH TEMPS WILL BE 5-10 DEGREES
BELOW NORMAL FRIDAY THROUGH SUNDAY.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 715 AM EDT MONDAY...

A COLD FRONT IN SOUTHEAST WV EARLY THIS MORNING WILL MOVE EAST
THROUGH THE FORECST AREA BY 18Z. UPSLOPE IFR/MVFR CIGS IN SE
WV/FAR SW VA...INCLUDING KBLF WILL GRADUALLY LIFT TO A VFR CIG BY
LATE MORNING.

THE BIGGEST AVIATION CONCERN TODAY IS THE GUSTY WINDS ASSOCIATED
WITH A STRONG LOW PRESSURE SYSTEM LIFTING NORTHEAST INTO NEW
ENGLAND. GUSTS OVER 25KTS POSSIBLE IN THE MOUNTAINS AND
FOOTHILLS...INCLUDING KROA...KBLF...AND KBCB WITH 15-25KT GUSTS
ESLEWHERE.

OTHERWISE...ENERGY ROTATING THROUGH THE UPPER TROF WILL COMBINE
WITH UPSLOPE AND INSTABILITY BELOW THE SUBSIDENCE INVERSION AND
STEEPISH LAPSE RATES AS SEEN ON MODEL SOUNDINGS TO SQUEEZE OUT A
FEW SPRINKLES AT KLWB AND KBLF THROUGH THE DAY.

WINDS WILL DIMINISH IN THE LATE AFTERNOON AS LOW PRESSURE EXITS
THE REGION. MVFR CIGS AGAIN FORECAST TO DEVELOP ALONG THE WESTERN
SLOPES...INCLUDING KLWB...KBLF AND PERHAPS KBCB LATE
TONIGHT...ALONG WITH PATCHY FOG OVER THE THE CLIMATOLOGICAL
FAVORED AREAS SUCH AT KLWB.


EXTENDED AVIATION DISCUSSION...
DRIER AIR PUSHING IN FOR TUESDAY-WEDNESDAY WILL BRING MAINLY VFR
CONDITIONS...BUT CANNOT RULE OUT LATE NIGHT FOG AT KBCB/KLWB...
ALTHOUGH THE LOW LEVELS MAY STAY DRY ENOUGH FOR LESS FOG COVERAGE.

VARIABLE CIGS EXPECTED UNDER ANOMALOUS UPPER LOW THROUGHOUT THE
REST OF THE WEEK. A FEW -SHRA NOT COMPLETELY OUT OF THE QUESTION
ACROSS EASTERN WV...ALONG WITH OCCASIONAL MVFR CIGS. TYPICAL FOG
POTENTIAL LESS THAN NORMAL FOR THIS TIME OF YEAR THROUGHOUT THE
WEEK BECAUSE OF TURBULENT MIXING AND PREVAILING CYCLONIC FLOW.
TOWARD THE END OF THE WEEK...AS THE UPPER LOW RETROGRADES JUST
WEST OF THE REGION...INCREASING POTENTIAL FOR SHRA/TSRA BUT MAINLY
SW OF THE TAF SITES INTO FRIDAY.

&&

.CLIMATE...
JULY 30TH RECORD LOWS:

ROANOKE......54...1997
BLUEFIELD....50...1981
DANVILLE.....60...1972/81/83/2013
LEWISBURG....46...2013
LYNCHBURG....52...1997
BLACKSBURG...50...1973/81


JULY 31ST RECORD LOWS:

ROANOKE......49...1914
BLUEFIELD....49...1997
DANVILLE.....55...1966
LEWISBURG....48...1997
LYNCHBURG....49...1997
BLACKSBURG...44...1997

&&

.EQUIPMENT...
THE WEATHER RADIO AT HINTON WEST VA TRANSMITTING ON FREQUENCY
162.425 MHZ REMAINS OFF THE AIR LIKELY DUE TO PHONE LINE PROBLEMS.
RESTORATION OF SERVICE IS NOT EXPECTED BEFORE NOON ON MONDAY.

&&

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

&&

$$
SYNOPSIS...DS/NF
NEAR TERM...DS/NF
SHORT TERM...PH
LONG TERM...CF
AVIATION...NF/PH
CLIMATE...PH
EQUIPMENT...JH


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