FXUS61 KRNK 270539
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1239 AM EST FRI NOV 27 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THE APPALACHIANS THIS
EVENING...BRINGING MUCH COLDER AIR ALONG WITH GUSTY WINDS AND
MOUNTAIN SNOW SHOWERS INTO FRIDAY NIGHT. HIGH PRESSURE WILL BUILD
EAST ACROSS THE SOUTHEAST STATES DURING THE WEEKEND ALLOWING FOR A
MODERATION IN TEMPERATURES THROUGH SUNDAY. THE NEXT FRONTAL SYSTEM
BRINGING THE NEXT CHANCE FOR RAIN WILL APPROACH FROM THE WEST
EARLY MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
LOW PRESSURE HAS SLOWED DOWN OVER THE ERN SECTIONS OF THE VA/NC
AREA WITH SHOWERS LOCKED IN PLACE OVER MY ERN CWA. AS THE UPPER
SHORTWAVE PUSHES INTO THE MID ATLANTIC OVERNIGHT...THESE SHOWERS
SHOULD EXIT. ON THE BACKSIDE...REGIONAL RADAR IS SHOWING PRECIP
MAKING IT TOWARD THE VA/KY BORDER. WIND HAS ALREADY PICKED UP
ACROSS THE NC MTNS WITH GUSTS UP TO 38 KNOTS OCCURRING. THE
CURRENT WIND ADVISORY AND HIGH WIND WARNING APPEAR IN GOOD
SHAPE...WITH STRONGEST WIND FIELDS STILL EXPECTED TO ARRIVE IN THE
09-15Z TIME FRAME PER THE 18Z NAM CROSS SECTIONS.
WITH THE LOW LEVEL WINDS TURNING MORE WESTERLY BY FRIDAY WILL SEE
ADVISORY SPEEDS FARTHER NORTH ALONG THE BLUE RIDGE ESPCLY GIVEN
DEEPER MIXING BY MIDDAY FRIDAY. THIS IN CONJUNCTION WITH THE VERY
WET SOILS MAY LEAD TO MORE FALLEN TREES AS WELL. THUS WILL BE
UPGRADING THE GOING ADVISORY TO A HIGH WIND WARNING ACROSS PARTS
OF THE NW NC MOUNTAINS FROM MID EVENING THRU FRIDAY EVENING...AND
KEEP AN ADVISORY FROM ALLEGHANY CTY NC TO ROANOKE VA FOR THE SAME
PERIOD.
AS FOR SNOWFALL...THE ACTIVITY IS DELAYED BY A FEW HOURS...BUT
HOLDING ONTO LIKELY SNOWFALL OVER THE SE WV MTNS LATE TONIGHT.
GROUND IS RELATIVELY WARM AND ACCUMULATING SNOW WILL PROBABLY
WAIT UNTIL AFTER MIDNIGHT...AND BEST WINDOW PROBABLY 09Z THROUGH
15Z FRIDAY. TRIMMED SNOW ACCUMULATIONS ACROSS THE SOUTH BUT HELD
ONTO THE 4-5 INCHES AMOUNTS ACROSS THE HIGHEST ELEVATIONS AND WEST
FACING SLOPES IN THE SNOW ADVISORY AREA.
KEPT TEMPERATURES TONIGHT CLOSE TO PREVIOUS SHIFT FROM THE UPPER
20S IN THE NORTHWEST TO THE UPPER 30S IN THE SOUTHEAST. WITH
STRONG CAA...PLAYED TEMPERATURES CLOSER TO ADJMAV WITH READINGS
FROM LOWER 30S IN THE WEST TO NEAR 50 DEGREES IN SOUTHSIDE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
UPSLOPE EVENT WILL BE WINDING DOWN FRIDAY NIGHT AS THE AXIS OF
DEEPER RH PULLS OUT IN WAKE OF THE EXITING COLD POOL...AND THE FLOW
GOES MORE ANTICYCLONIC AHEAD OF SURFACE RIDGING BUILDING IN FROM THE
SW. MAY STILL HAVE A BAND OF LIGHTER SNOW SHOWERS ONGOING MAINLY
WESTERN GREENBRIER CTY DURING THE EVENING BEFORE THINGS TAPER TO
FLURRIES OR JUST CLOUDS OVERNIGHT. THUS HAVE CUT POPS BACK MORE WITH
ONLY LOW CHANCES MAINLY SE WVA ZONES DURING THE EVENING AND
BASICALLY DRY AFTER MIDNIGHT. HOWEVER WITH YET ANOTHER S/W ROTATING
AROUND THE 5H TROF EXPECT WINDS TO REMAIN GUSTY DURING THE EVENING
WITH SPEEDS ALONG PARTS OF THE BLUE RIDGE POSSIBLY STILL NEAR
ADVISORY/WARNING LEVELS EARLY ON SO WILL EXTEND THE NPW PRODUCTS TO
9 PM. OTRW SKIES MAINLY CLEAR AWAY FROM THE UPSLOPE NW OVERNIGHT BUT
COLD WITH LOWS LOW/MID 20S WEST TO LOW 30S SE DESPITE SOME WIND
GRADIENT REMAINING THRU SAT MORNING.
UPPER FLOW QUICKLY TRANSITIONS TO MORE ZONAL FLOW FOR THE WEEKEND
WITH LOTS OF WARM AIR FLOODING BACK INTO THE AREA PER HIGH PRESSURE
TO THE SOUTH AND DEEP WESTERLY FLOW ALOFT. LOTS OF DRY AIR THRU THE
COLUMN SUPPORTS A SUNNY BUT STILL RATHER BREEZY AND MILDER AFTERNOON
WITH HIGHS AROUND 50 SE WVA TO 55-60 SE. NEXT COLD FRONT WILL BE
APPROACHING FROM THE NW SUNDAY AS THE SURFACE HIGH SLIDES OFF THE SE
COAST. MODELS SHOW SOME INCREASE IN HIGH CLOUDS SUNDAY AFTERNOON IN
RESPONSE TO BACKING ALOFT AND RH ADVECTION OTRW STILL MAINLY SUNNY.
GIVEN PROGGED 85H TEMPS NEAR +10C EXPECT HIGHS TO REACH THE LOW/MID
60S PIEDMONT AND MID/UPPER 50S WEST. CLOUDS SHOULD INCREASE ESPCLY
WESTERN HALF SUNDAY NIGHT AS THE FRONT EDGES INTO THE OHIO VALLEY
BUT STILL DRY FOR NOW GIVEN LINGERING DRY LOW LEVELS OFF FCST RAOBS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
TWO CHANCES FOR RAIN NEXT WEEK...MONDAY AND WEDNESDAY. THE ONE
SET FOR MONDAY WILL BE WITH A SLOW MOVING COLD FRONT. THE ONE FOR
WEDNESDAY WILL BE AN OVER RUNNING EVENT THAT COULD LINGER INTO
THURSDAY MORNING. BOTH WILL HAVE ABUNDANT GULF MOISTURE ASSOCIATED
WITH IT AND MODERATE RAIN COULD FALL. TEMPERATURES MONDAY WILL RUN
ABOVE NORMAL WITH THE FRONT MOVING SLOWLY TO THE EAST. AS TYPICAL
WITH AN AUTUMN SEASON OVER RUNNING EVENT...WEDNESDAY AFTERNOON
TEMPERATURES WILL BE ABOUT 10 DEGREES BELOW NORMAL. FOR THE MOST
PART...TEMPERATURES SHOULD REMAIN ABOVE FREEZING WHEN THE RAIN IS
FALLING. WILL NEED TO WATCH TUESDAY NIGHT/WEDNESDAY MORNING
TEMPERATURES AND DEW POINTS BECAUSE IF RAIN ENTERS PRIOR TO
DAWN...FROZEN P-TYPE IS POSSIBLE. AT THIS TIME...GROUND
TEMPERATURES STILL FAIRLY MILD...IN THE 40S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
NW FLOW INCREASING OVERNIGHT WITH SCT SNOW SHWRS MOVING INTO THE
WEST AROUND 09Z. CIGS HAVE LOWERED TO MVFR AT BLF/LWB ALREADY AND
SHOULD REMAIN THERE THROUGH MUCH OF DAY FRIDAY. NOT ANTICIPATING
THE SNOW SHWRS TO LOWER VSBYS VERY MUCH AT BLF...AND PROBABYL ONLY
FLURRIES AT LWB...BUT THERE COULD BE BRIEF PERIODS OF TIME AT BLF
WITH MVFR VSBYS AND SOME HEAVIER SNOW SHWRS. MAYBE DUSTING OF
ACCUM BETWEEN 09 AND 15Z. THE MAIN AVIATION IMPACT FURTHER EAST
WILL BE THE STRONGER WINDS. LOOKING AT GUSTS AS HIGH AS 45 KNOTS
POSSIBLE INVOF ROANOKE...ESPECIALLY DURING THE 09-15Z TIME FRAME.
CIGS WILL START TO IMPROVE LATE FRIDAY MORNING...WITH VFR
CONDITIONS RETURNING TO BLF...AND LWB BY 17Z-21Z.
GUSTY WINDS MAY CONTINUE THROUGH FRIDAY NIGHT AS GRADIENT REMAINS
STRONG...BEFORE EVENTUALLY HIGH PRESSURE BUILDS BACK INTO THE
REGION BY SATURDAY AND SUNDAY. THIS WILL END THE UPSLOPE CLOUDS
AND PRECIPITATION AND RETURN BLF BACK TO VFR CONDITIONS. NEXT
FRONTAL SYSTEM WITH A CHANCE OF RAIN AND POSSIBLE IFR CONDITIONS
APPROACHES FROM THE WEST ON MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ016-017-022.
HIGH WIND WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ015.
NC...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR NCZ002.
HIGH WIND WARNING UNTIL 9 PM EST THIS EVENING FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ042-043-045.
&&
$$
SYNOPSIS...JH/SK
NEAR TERM...JH/KK/WP
SHORT TERM...JH
LONG TERM...RCS
AVIATION...KK/SK/WP
