FXUS61 KRNK 060004
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
704 PM EST SAT DEC 5 2009
.SYNOPSIS...
LOW PRESSURE IS MOVING RAPIDLY NORTHEAST ALONG THE JERSEY COAST
AND WILL MOVE AWAY FROM THE AREA TONIGHT. COLD HIGH PRESSURE WILL
BUILD IN BEHIND THE SYSTEM FOR SUNDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
ALL HEADLINES HAVE EXPIRED.
MAIN CONCERN GOING FORWARD IS FALLING TEMPS AND POTENTIAL FOR
REFREEZE OF SNOWMELT. AS COLDER AIR POURS INTO THE REGION ON THE
NORTHWEST WINDS TEMPS WILL SLIP BLO FREEZING. BY MIDNIGHT...TEMPS
WILL LIKELY BE IN THE LOWER 20S ACROSS THE MTNS...AND WITH THE
SNOW COVER...CLEARING SKIES AND WEAKENING WINDS...WILL DROP INTO
THE TEENS AFTER MIDNIGHT.
SUNDAY WILL FEATURE LOTS OF SUN AND LIGHT WINDS...BUT WITH A COLD
AIRMASS IN PLACE AND SNOW COVER IN THE MTNS...I HAVE GONE WITH
HIGH ON THE COOL SIDE OF GUIDANCE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
RIDGING AT THE SURFACE AND ALOFT WILL PUSH EAST OVER THE ATLANTIC
OVERNIGHT SUNDAY. MODELS HAVE BEEN SLOWER WITH A WEAK SHORTWAVE
PUSHING ACROSS THE FORECAST AREA. A SOUTHERLY FLOW WILL BRING IN
MOISTURE AHEAD OF THIS FEATURE INCREASING CLOUD COVER MONDAY. THE
LATEST MODEL RUNS HAVE MINOR DIFFERENCES ON THE TIMING OF THE
PRECIP. HAVE LEANED TOWARD THE SLOWER SOLUTION HAVING SLIGHT CHANCE
ALONG AND WEST OF THE BLUE RIDGE MOUNTAINS BEGINNING AT 18Z MONDAY.
HOWEVER...WOULD NOT BE SURPRISED TO SEE THIS SLOW DOWN A BIT IN
LATER RUNS.
TEMPERATURES WILL NOT BE QUITE AS COLD SUNDAY NIGHT AS THE PREVIOUS
NIGHT...AS 850MB TEMPERATURES SEEM TO RISE A BIT WITH A LIGHT
SOUTHERLY FLOW PUSHING SLIGHTLY WARMER AIR INTO THE COUNTY WARNING
AREA. HOWEVER...CLOUD COVERAGE WILL BE LOW AND WINDS WILL REMAIN
LIGHT WHICH WILL ALLOW TEMPERATURES TO FALL INTO THE MID TO UPPER 20
RANGE ACROSS THE BOARD.
EXPECT THE SLIGHT CHANCE POPS IN THE WEST CONTINUING THROUGH TUESDAY
MORNING THEN INCREASING TO CHANCE FOR THE AFTERNOON. WITH WARM AIR
ADVECTION CONTINUING...TEMPERATURES WILL RISE INTO THE MID TO UPPER
40S ACROSS THE FORECAST AREA.
MOST OF THE ENERGY LOOKS TO APPROACH THE AREA TUESDAY NIGHT THUS
HAVE MAINTAINED THE LIKELY POPS LATE. COLD AIR ADVECTION WILL BE
FILTERING IN BRIEFLY FROM THE NORTHWEST TUESDAY NIGHT WITH A WIDE
RANGE OF 850MB TEMPS RANGING FROM PLUS 5 TO MINUS 7 FROM
SOUTHEAST TO NORTHWEST RESPECTIVELY. BUFKIT SOUNDINGS SUPPORT NEAR
TO BELOW FREEZING TEMPERATURES FROM THE UPPER LEVELS DOWN TO THE
SURFACE AT MOST ALL OF OUR SITES...WITH THE EXCEPTION OF DANVILLE
AND LYNCHBURG WHICH WILL HOVER CLOSE TO FREEZING AT THE SURFACE.
EXPECT RAIN CHANGING TO SNOW AFTER SUNSET TUESDAY AND WITH A WARM
NOSE ADVECTING IN NEAR 850MB...THE PRECIP WILL THEN CHANGE TO A
WINTRY MIX ENCOMPASSING SNOW...SLEET AND FREEZING RAIN. DANVILLE
AND THE PIEDMONT AREAS OF VIRGINIA AND NORTH CAROLINA WILL BE THE
AREAS MOST LIKELY TO SEE ALL RAIN UNTIL JUST BEFORE SUNRISE BEFORE
ANY FREEZING RAIN BEGINS. LYNCHBURG WILL ALSO REMAIN MOSTLY RAIN
BUT HAS A HIGHER PROBABILITY OF SEEING A MIX OF SLEET AND FREEZING
RAIN TOWARD DAWN.
HAVE LEANED TOWARD THE MOS GUIDANCE FOR TEMPERATURES TUESDAY NIGHT
DUE TO THE COLD AIR ADVECTION PUSHING OVER THE AREA BUT MOST OF THE
COLDER AIR WILL BANK UP AGAINST THE APPALACHIANS OF SOUTHEAST WEST
VIRGINIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A HYBRID DAMMING EVENT IS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY. GFS
WAS INDICATING SOME WINTRY MIXTURE OF SLEET...FREEZING RAIN AND RAIN
FOR EARLY WEDNESDAY BECOMING A COLD RAIN. THE ECMWF IS WARMER AND
DEPICTS ONLY RAIN ACROSS THE ENTIRE CWA. WILL ALLOW FOR SOME WINTRY
MIX EARLY WEDNESDAY WITH THE CONSISTENCY OF THE MODELS.
HIGH PRESSURE OVER THE REGION ON TUESDAY INTO WEDNESDAY SLIDES
EAST...WHILE STRONG LOW PRESSURE WILL TRACK FROM THE PLAINS
NORTHEASTWARD OVER THE GRTLKS/OH VALLEY REGION. AS THE LOW LIFTS
NORTHEAST A COLD FRONT WILL PUSH EAST ACROSS OUR REGION WEDNESDAY
AND INTO THE ATLANTIC OCEAN ON WEDNESDAY NIGHT. KEEP THE BEST POPS
CHANCE IN THE NORTH WESTERN MOUNTAINS WEDNESDAY NIGHT INTO THURSDAY.
HIGH PRESSURE WILL BUILD EAST INTO THE AREA FROM THE TENNESSEE
VALLEY ON THURSDAY INTO THURSDAY NIGHT. KEPT SOME CHCY POPS IN THE
WEST WITH THE PASSAGE OF A WARM FRONT ON FRIDAY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MVFR CONDITIONS WITH ISOLD IFR IN LOW CLOUDS AND PCPN WILL
GRADUALLY RISE TO VFR OVERNIGHT. THE AREA OF RAIN AND SNOW WILL
EXIT OUR CWA EARLY TONIGHT...AS THE LOW PRESSURE CENTER MOVES
QUICKLY NORTHEAST. CLOUDS WILL BECOME SCATTERED EAST OF THE BLUE
RIDGE AROUND 06Z WITH ROA...LYH AND DAN ALL VFR BY MORNING. THE
CLEARING WILL BE SLOWER AT BLF AND LWB DUE TO A WEST TO NORTHWEST
LOW LEVEL WIND AND RESIDUAL LOW LEVEL MOISTURE. A FEW SNOW
FLURRIES ARE POSSIBLE EARLY TONIGHT IN THE WEST. ALL SITES SHOULD
BECOME VFR BETWEEN AROUND 10Z SUNDAY.
HIGH PRESSURE WILL CONTINUE THE VFR CONDITIONS INTO MONDAY.
A WEAK COLD FRONT MAY BRING BRIEF MVFR CONDITIONS IN CLOUDS AND
POSSIBLY LIGHT PRECIP BY MONDAY NIGHT INTO TUESDAY IN THE MOUNTAINS.
IFR CONDITIONS MAY BE POSSIBLE TUESDAY NIGHT AND WEDNESDAY WITH A
LARGER LOW PRESSURE SYSTEM DEVELOPING IN THE SOUTHERN PLAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JJ
NEAR TERM...JJ/PM
SHORT TERM...REB
LONG TERM...KK
AVIATION...JJ/KK
