Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 191740
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1240 PM EST FRI DEC 19 2014

.SYNOPSIS...
PERSISTANT CLOUDS THROUGH TONIGHT. A WEAK DISTURBANCE PASSES
TO OUR SOUTH SATURDAY. THIS MAY CLIP THE EXTREME SOUTHERN COUNTIES
WITH SOME LIGHT SNOW OR RAIN. DRY ON SUNDAY. NEXT SYSTEM APPROCHES
FROM THE SOUTH ON MONDAY AND MAY CLIP OUR EASTERN MOUNTAIN
COUNTIES WITH SOME PRECIPITATION.


&&

.NEAR TERM /THROUGH SATURDAY/...
UPDATED TEMPS A TAD LOWER TODAY WITH CLOUD COVER. SOUNDINGS
INDICATED THAT CLOUDS WILL PERSIST THROUGHOUT TODAY. SOME EROSION
TAKING PLACE IN SW VA AND EXTREME SOUTHERN WV TO THE GREENBRIER
VALLEY. BUT HIGH AND MID CLOUDS WORKING THEIR WAY IN FROM THE
SOUTH FROM THE NEXT SYSTEM WILL KEEP ANY PEAKS OF THE SUN TO A
MINUMUM. OTHERWISE REST OF PACKAGE ON TRACK AND NO OTHER MAJOR
CHANGES EXPECTED.

PREVIOUS DISCUSSION...
RAGGED DECK OF STRATCU AND SOME MID LEVEL CLOUDS WILL
CONTINUE TO MOVE ACROSS THE CWA EARLY THIS MORNING INTO EARLY
AFTERNOON. THERE ARE SOME BREAKS IN CLOUDS...ESPECIALLY ACROSS
SOUTHERN WV...AND PARTS OF SOUTHERN OH. BUT THE CLOUD DECK IS
THICKER OVER THE FAR NORTH WHERE A WEAK S/W AND A FEW SNOW SHOWERS
WERE MOVING ACROSS SOUTHERN PA AND THE EASTERN WV PANHANDLE.

SFC HIGH WILL DRIFT ACROSS THE GREAT LAKES TODAY AND SOME DRYING OF
THE ATMOSPHERIC COLUMN WILL ALLOW MORE WIDESPREAD BREAKS IN THE
CLOUDS...AND ANY LINGERING FLURRIES IN KEKN AREA TO COME TO AN END.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
TREND CONT WITH SUPPRESSION OF SYSTEM FOR SATURDAY. HAVE TIGHTENED
UP THE POP GRADIENT SIGNIFICANTLY...CONFINING POPS TO SW VA AND SE
WV...WHERE HIGH POPS WERE MAINTAINED ACROSS SW VA SATURDAY
MORNING. THIS STREAKING BAND OF WHAT SHOULD BE MAINLY -SN...WILL
QUICKLY SCOOT OFF TO THE E BY MIDDAY WITH JUST SOME FLURRIES OR
SPRINKLES ACROSS THOSE LOCATIONS FOR THE AFTERNOON. TOUGH TO
FIGURE OUT THE CLOUD COVER WITH VARYING HEIGHTS TO BASES
ANTICIPATED FOR THE REGION. SUSPECT QUITE A BIT OF STRATUS LINGERING
ESPECIALLY ACROSS S ZONES WITH BEST CHANCE OF AT LEAST BECOMING
BKN N OF I64 CORRIDOR. LITTLE IN THE WAY OF FLOW BENEATH
SUBSIDENCE INVERSION MAY PREVENT MUCH IN THE WAY OF MIXING THE
STRATUS OUT THOUGH. INHERITED TEMPS CLOSE TO NEW GUIDANCE WITH
LITTLE TWEAKING.

S/W RIDGING WORKS IN ON SUNDAY AS WAA SLOWLY BEGINS TO SPREAD
ACROSS THE AREA. THE LOW LEVEL FLOW TO VEER AROUND TO SE IN THE
AFTERNOON. THIS SHOULD HELP IN ERADICATING ANY LINGERING STRATUS
ALTHOUGH FLOW IS RATHER WEAK. WILL ALSO HAVE SOME WAA FROM THE S
TO HELP. UNFORTUNATELY...QUITE A BIT OF CIRRUS WILL BE STREAKING
IN FROM THE W IN THE AFTERNOON...TO FILTER WHAT SUNSHINE WE MANAGE
TO GET. INHERITED TEMPS CLOSE TO NEW GUIDANCE WITH LITTLE
TWEAKING.

CIRRUS SUNDAY NIGHT ALONG WITH STRATUS DEVELOPING ON E SLOPES
SHOULD HELP TO KEEP TEMPS IN CHECK. WILL BE WATCHING FOR UPPER AIR
DISTURBANCE TO ROTATE OUT OF THE BASE OF AN AMPLIFYING UPPER TROF
OVER THE PLAINS. SUSPECT SURFACE CYCLOGENESIS WILL OCCUR ALONG SE
COAST AS THIS UPPER WAVE TRACKS THRU TN VALLEY INTO OUR NECK OF
THE WOODS. FEEL BULK OF HVY PRECIP ASSOCIATED WITH THIS WILL
REMAIN E OF THE CWA...CLIPPING MOUNTAIN ZONES MONDAY MORNING. THIS
IS WHERE HIGH POPS WERE CODED UP WITH PERHAPS ANOTHER MAXIMA OVER
SE OH. THINK STRENGTHENING DOWNSLOPING SE FLOW WILL KEEP PRECIP
CHANCES LOW ACROSS THE LOWLANDS. THERE WILL BE A CAD EVENT TO CONTEND
WITH AS THE SURFACE HIGH WILL BE POSITIONED OVER NEW
ENGLAND...ALBEIT WEAK. THIS CAD MAY BE STRENGTHENED INITIALLY AS
DRY LYR AROUND H85 MOISTENS UP MONDAY MORNING. AS A RESULT FELT
THE COOLER NAM WAS THE WAY TO GO ACROSS OUR CAD LOCATIONS...IE E
SLOPES AND GREENBRIER VALLEY. WETBULBING PROBABLY WOULD SUPPORT A
BRIEF BURST OF SN ON THE LEADING EDGE MONDAY MORNING BEFORE
QUICKLY TRANSITIONING TO FZRA AS WAA ALOFT OVERWHELMS THE AREA.
THERE COULD BE AN INCH OF SN BEFORE THIS TRANSITION WITH SOME
ICING TO WORRY ABOUT THEREAFTER...UNTIL MIDDAY. WILL INSERT A
MENTION IN HWO FOR POTENTIAL HEADLINES SHOULD CONFIDENCE INCREASE.
MOST OF THE PRECIP BECOMES CONFINED TO DEPARTING SURFACE LOW OFF
THE E COAST IN THE AFTERNOON WITH JUST A FEW -SHRA
EXPECTED...MAINLY ACROSS SE OH. TRIED TO CODE UP SOME WARMER TEMPS
E OF I79 CORRIDOR TO W SLOPES AIDED BY SOME DOWNSLOPING...WHERE
SOME MID 50S POSSIBLE IN THE AFTERNOON. HAVE GENERALLY UPPER 40S
TO LOWER 50S ELSEWHERE. CAD LOCATIONS WILL STRUGGLE TO GET OUT OF
THE 30S HOWEVER.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL MOVE NORTHEAST ALONG THE EAST COAST
MONDAY...CREATING PRECIPITATION...MAINLY ACROSS EASTERN ZONES MONDAY
AND MONDAY NIGHT. DEPENDING ON SURFACE TEMPERATURES...COULD BE A
PERIOD OF SLEET OR FREEZING RAIN MONDAY MAINLY ACROSS MOUNTAIN ZONES
AND NORTHERN WV. THIS LOW WILL EXIT OFF TO THE EAST ON TUESDAY...TO
BE FOLLOWED BY ANOTHER LOW...WHICH WILL MOVE NORTHEAST OUT OF THE
SOUTHERN U.S TOWARDS THE OHIO VALLEY...AHEAD OF A LOW AND UPPER
TROUGH ACROSS THE UPPER MIDWEST. WITH GOOD SOUTHERLY FLOW...PW
VALUES WILL RISE TO AROUND AN INCH WITH THE SYSTEM. IN
ADDITION...GUSTY WINDS ARE EXPECTED TO DEVELOP AS THE SYSTEM MOVES
THROUGH THE REGION...PARTICULARLY WEDNESDAY AND WEDNESDAY
NIGHT...BEHIND THE COLD FRONT...WHICH WILL MOVE THROUGH THE AREA
TUESDAY NIGHT/EARLY WEDNESDAY. BASED ON THIS TIMING...COULD SEE
FALLING TEMPERATURES THROUGHOUT THE DAY CHRISTMAS EVE...WHICH WOULD
RESULT IN A SNOWIER/MORE MIXED PRECIP FORECAST THAN CURRENTLY
ADVERTISED. STILL LOOKING LIKE SOME SORT OF WINTER HEADLINES MAY BE
NECESSARY DURING THIS TIME PERIOD...BUT WITH SO MANY UNCERTAINTIES
IN THE FORECAST...WILL LEAVE OUT OF THE HWO FOR NOW.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
MAINLY AN MVFR CLOUD DECK IN PLACE THIS AFTEROON OVER TAF SITES.
THIS WILL CONTINUE THROUGH THE OVERNIGHT WITH THE EXCEPTION OF BKW
WHICH MAY GO VFR CIGS LATER THIS AFTERNOON BEFORE HIGH AND MID CLOUDS
START INCREASING FROM THE SOUTHWEST...AS NEXT SYSTEM APPROCHES FOR
SATURDAY. MVFR CIGS GRADUALLY BECOME MAINLY VFR TOWARDS 12Z
SATURDAY NORTH. AFT 12Z CLOUDS WILL INCREASE IN COVERAGE AGAIN AS
SYSTEM PASSES TO OUR SOUTH.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z
SATURDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING TRANSITION FROM MVFR CIGS TO VFR CIGS
MAY VARY TOWARDS 12Z SATURDAY. ALSO, TIMING OF REFORMATION OF MVFR
CIGS OVER SOUTHERN WV SATURDAY MORNING MAY VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EST 1HRLY       13   14   15   16   17   18   19   20   21   22   23   00
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    M    M    M    M    M    M    M    M    M    M    M
PKB CONSISTENCY  H    M    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H

AFTER 18Z SATURDAY...
IFR POSSIBLE IN LIGHT WINTRY MIX OVER SOUTHERN COUNTIES SATURDAY
AND SATURDAY NIGHT. ANOTHER SYSTEM MAY BEING IFR TO MOUNTAINS
SUNDAY NIGHT MONDAY WITH A WINTRY MIX.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JS/SL/LS
NEAR TERM...JS
SHORT TERM...LS
LONG TERM...SL
AVIATION...JS







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