Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 270606
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
106 AM EST THU NOV 27 2014

.SYNOPSIS...
A FAST MOVING AREA OF LOW PRESSURE WILL BRING MORE PRECIPITATION
TO THE REGION OVERNIGHT AND INTO THE MORNING...MAINLY IN THE FORM
OF SNOW WEST OF THE BLUE RIDGE AND RAIN TO THE EAST. UPSLOPE SNOW
SHOWERS WILL THEN CONTINUE ALONG THE FAR WESTERN SLOPES OF THE
RIDGE THROUGH FRIDAY MORNING AS HIGH PRESSURE BUILDS IN...BRINGING
QUIET WEATHER TO THE FORECAST THROUGH SATURDAY. A WEAK FRONT WILL
APPROACH FROM THE NORTHWEST AND BRING A CHANCE OF SHOWERS BACK TO
THE FORECAST AS WE CLOSE OUT THE WEEKEND AND HEAD INTO THE NEW
WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 950 PM EST WEDNESDAY...

AN AREA OF MAINLY MIXED PRECIPITATION ACROSS THE TENNESSEE VALLEY
MAKING ITS WAY EASTWARD IN ASSOCIATION WITH A STRONG SHORT-WAVE
DIGGING THROUGH THE UPPER TROUGH. PUSHED BACK THE ARRIVAL OF
PRECIP TO AROUND 2 AM IN THE WEST AND TRANSITING MAINLY THE
SOUTHERN PORTIONS OF THE CWA THROUGH MID-MORNING. WINTER WEATHER
ADVISORY STILL GOES INTO EFFECT AFTER MIDNIGHT BUT MAY BE HARD TO
REACH THE 4-INCH AMOUNTS AT LEAST AT THE LOWER ELEVATIONS WHERE
MOST PEOPLE LIVE...MORE LIKE 1 TO 2 INCHES SEEMS PROBABLE. TEMPS
WILL BE EXTREMELY MARGINAL FOR ACCUMULATING

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 330 PM EST WEDNESDAY...

UPSLOPE SNOW SHOWERS WILL CONTINUE FOR THE FAR WESTERN SLOPES AS
HIGH PRESSURE BUILDS IN...BEFORE DISSIPATING EARLY FRIDAY
MORNING. THIS HIGH WILL BRING US QUIET WEATHER INTO THE WEEKEND
BEFORE IT SLIDES OFF TO OUR EAST AND SLY RETURN FLOW SETS UP A
WARM AIR ADVECTION PATTERN. MAIN THRUST OF ANY LIFT AND MOISTURE
CAPABLE OF SQUEEZING OUT PRECIPITATION REMAINS OFF TO OUR WEST AHEAD
OF NEXT WEAK APPROACHING FRONT. THIS SHOULD KEEP US DRY INTO THE
LATTER PORTION OF THE WEEKEND.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 PM EST WEDNESDAY...

A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER FLORIDA LIMITING
GULF AND ATLANTIC MOISTURE FROM ENTERING THE REGION SUNDAY AND
MONDAY. THIS RIDGE WILL ALSO ALLOW THE REGION TO WARM TO 10F ABOVE
NORMAL. MONDAY AFTERNOON INTO MONDAY NIGHT...A BACK DOOR FRONT WILL
TRY AND PUSH SOUTH OF THE AREA. WITH A STRONG AND BROAD RIDGE ACROSS
THE SOUTH...EXPECTING LATER MODEL RUNS TO DELAY THE FRONTAL PASSAGE
UNTIL SOMETIME TUESDAY. SINCE THE ECM/GFS HAS THIS FRONT ENTERING
THE AREA MONDAY AND MONDAY NIGHT...WILL HAVE SLIGHT/CHANCE POPS FOR
RAIN SHOWERS OVER THE AREA. ALSO HAVE SLIGHT/CHANCE POPS TUESDAY FOR
A POSSIBLE FRONTAL PASSAGE OR FOR THE FRONT STALLING IN THE REGION.
EITHER WAY AND/OR EITHER DAY...TEMPERATURES AND THICKNESSES ARE WARM
TO KEEP ANY PRECIPITATION FALLING AS RAIN. SURFACE HIGH PRESSURE
WILL MOVE OVER NEW ENGLAND FOLLOWING THE FRONTAL PASSAGE AND REMAIN
IN THE AREA TROUGH THE REMAINDER OF THE WORKWEEK. EVEN THOUGH THIS
WEDGE IS STRONG (1035MB)...MODELS REMAINING WARM AND CLOSE TO
SEASONAL TEMPERATURES.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM EST THURSDAY...

SURFACE OBSERVATIONS INDICATE A LOW PRESSURE SYSTEM OVER FAR
WESTERN VIRGINIA THIS MORNING...TRAVELING EAST. THE LOW IS BRINGING
WITH IT BANDS A LIGHT SNOW THAT WILL SPREAD ACROSS THE MOUNTAINS
THROUGH THE NIGHT. CEILINGS ACROSS THE AREA ARE VARIABLE...
RANGING FROM IFR TO MOSTLY CLEAR. HOWEVER...PATCHY DENSE FOG IS
DEVELOPING WHERE CEILINGS SCATTER...MAKING MOST OF THE REGION LOW
MVFR/IFR AS A NET RESULT.

POOR FLIGHT CONDITIONS WILL PERSIST THROUGH MUCH OF THE NIGHT AS
SNOW BANDS PASS ACROSS THE MOUNTAINS...CHANGING OVER TO RAIN IN
THE WARMER AIR EAST OF THE BLUE RIDGE. ONCE THE LOW PASSES EAST
LATE THURSDAY MORNING...HIGH PRESSURE WILL BEGIN TO BUILD INTO THE
AREA...WITH WIND SPEEDS FROM THE WEST GUSTING 15KT TO 25KT...
TOPPING 30KT AT TIMES. CEILINGS WILL ALSO IMPROVE TO VFR FOR
ROA/LYH/DAN...HOWEVER THE TRANSITION TO VFR WILL BE MORE GRADUAL
FOR BLF/BCB/LWB...TAKING UNTIL LATE EVENING.

EXTENDED DISCUSSION...
HIGH PRESSURE WILL PASS ACROSS THE REGION FRIDAY...RESULTING IN
VFR CONDITIONS AREAWIDE. A COLD FRONT WILL PASS ACROSS THE REGION
ON MONDAY...BRINGING A RETURN OF SUB-VFR CONDITIONS.

&&

.HYDROLOGY...
STORM TOTAL PRECIPITATION AMOUNTS RANGED FROM ABOUT 0.50 TO 1.25
INCHES OF LIQUID EQUIVALENT WITH A FEW GAGES PICKING UP IN EXCESS
OF 1.50 INCHES MAINLY ACROSS PARTS OF THE NEW RIVER AND UPPER
ROANOKE AND DAN RIVER BASINS. THE LESSER AMOUNTS WERE GENERALLY
OBSERVED OVER THE WESTERN BASINS INCLUDING THE GREENBRIER AND
UPPER JAMES. RADAR PRECIPITATION ESTIMATES EXTREMELY CONTAMINATED
BY BRIGHT BAND EFFECTS. RUNOFF CAUSING SMALLER STREAMS TO SHOW
SOME NICE RISES BUT ALL WELL WITHIN BANKS.

&&

.EQUIPMENT...
AS OF 1030 AM EST WEDNESDAY...

VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WAS MALFUNCTIONING
AGAIN. PARTS HAVE BEEN ORDER BUT THE REPAIR MAY NOT BE UNTIL
MONDAY. THE VISIBILITY AT KLYH WILL BE AUGMENTED BY STAFF WHEN THE
CONTROL TOWER IS OPEN...OTHERWISE THE VISIBILITY WILL BE MISSING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009-
     015.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ508.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/PC
SHORT TERM...MBS
LONG TERM...RCS
AVIATION...NF/PC
HYDROLOGY...PC
EQUIPMENT...AMS



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