FXUS61 KRLX 291437
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
937 AM EST SUN NOV 29 2009
.SYNOPSIS...
HIGH PRESSURE IN CONTROL TODAY. COLD FRONT ARRIVES LATE TONIGHT
BRINGING RAIN AND SNOW SHOWERS INTO MONDAY. HIGH PRESSURE RETURNS
TUESDAY. LOW PRESSURE APPROACHES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLEAR SKIES HANGING ON BUT TWO BANKS OF CLOUDS ARE APPROACHING...AC
FROM THE SOUTHWEST AND CI FROM THE WEST. HAVE ADJUSTED SKY GRIDS TO
HANDLE THESE. THINK PRECIP HOLDS OFF UNTIL AFTER 00Z...LOCAL MODELS
AGREE...AND HAVE BACKED OFF A FEW HOURS ON POP GRIDS. HIGH
TEMPERATURES LOOK DECENT AND DID NOT CHANGE THOSE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
COLD FRONT WILL PUSH THROUGH AND UPPER LEVEL TROUGH AXIS FOLLOWS
CLOSELY BEHIND LATE MONDAY AS HIGH PRESSURE BEGINS TO NOSE IN FROM
THE SOUTHWEST. NORTHWEST FLOW KEEPS SNOW SHOWERS GOING IN THE
NORTHEAST MOUNTAINS THROUGH MONDAY NIGHT. LOW LEVEL MOISTURE WILL BE
THE LAST TO CLEAR WITH AN ABUNDANCE OF DRY AIR ALOFT IN THE BROAD
SCALE UPPER LEVEL RIDGE THAT IS NOW IN CONTROL. BRIEF PERIOD OF
CLEAR SKIES OCCURS EARLY TUESDAY NIGHT BEFORE CIRRUS ADVECTS
NORTHEASTWARD IN ADVANCE OF THE NEXT AREA OF LOW PRESSURE THAT WILL
ORGANIZE IN THE NORTHERN GULF OF MEXICO.
NO SIGNIFICANT TEMPERATURE CHANGES MADE IN THE SHORT TERM AS NEW
GUIDANCE VALUES CLOSELY RESEMBLE PREVIOUS FORECAST. STILL USING BIAS
CORRECTED BLENDED NUMBERS AS A STARTING POINT FOR FORECAST HIGHS AND
LOWS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SOUTHERN STREAM WAVE TO RIDE NORTH ALONG THE APPALACHIAN MOUNTAINS
LATE TUESDAY NIGHT INTO THURSDAY. BOTH GFS AND EUROPEAN MODELS STILL
SHOW SOME DIFFERENCES IN HANDLING THIS WAVE...WITH LATEST RUNS OF
THE GFS SHOWING SIGNS THAT IT WILL SHIFT ITS SOLUTION TO WHAT
PREVIOUS EUROPEAN RUNS WERE SHOWING. HOWEVER..IT STILL IS A LITTLE
TO0 PROGRESSIVE WITH NRN STREAM ENERGY DROPPING INTO THE NRN NORTH
CENTRAL US.
THE STORM TRACK OF THIS SRN STREAM ENERGY WILL PLAY A BIG ROLE IN
HOW OUR FORECAST PLAYS OUT...AND CURRENT THOUGHT IS THAT FOLLOWING
THE ECMWF AND ENSEMBLE SOLUTIONS AS ARE HPC GRIDS...WILL BE THE BEST
COURSE OF ACTION. ONLY CHANGE WAS TO WARM TEMPS SLIGHTLY AHEAD OF
SRN STREAM FEATURE...AND THIS MAY DELAY ANY SWITCH OVER TO SNOW WITH
AS CAA OCCURS THURSDAY. WRAP AROUND MOISTURE COUPLED WITH AN 850H
THERMAL TROUGH WILL LINGER FRIDAY FOR A CONTINUATION OF MOUNTAIN
SNOW SHOWERS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL AS HIGH PRESSURE REMAINS IN CONTROL WITH
LIGHT SOUTHWEST FLOW DEVELOPING. MODERATE SOUTHWEST FLOW ALOFT
WILL BE A BIT STRONGER THROUGH 14Z. THIS MAY GIVE RISE TO LOW
LEVEL WIND SHEAR DURING THIS TIME...WITH WINDS OF 30-35 KNOTS JUST
ABOVE DECOUPLED BOUNDARY LAYER UNTIL IT MIXES DOWN.
HIGH CLOUDS ARRIVING FROM THE SOUTH THIS MORNING...WILL LOWER AND
THICKEN DURING THE AFTERNOON BUT REMAIN ABOVE 10KFT FROM THE OHIO
RIVER EAST THROUGH 20Z SUNDAY.
A COLD FRONT WILL APPROACH FROM THE WEST THIS EVENING STRENGTHENING
THE SOUTHWEST FLOW...AND PRODUCING MVFR/IFR CONDITIONS ALONG RAIN
SHOWERS OVERNIGHT.
AFTER 12Z MONDAY...
IFR CONDITIONS POSSIBLE DUE TO LINGERING LIGHT SNOW ALONG THE
EASTERN MOUNTAINS MONDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...CL
SHORT TERM...26
LONG TERM...KMC
AVIATION...ARJ
