Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 270323
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1020 PM EST WED NOV 26 2014

.SYNOPSIS...
A WEAKER CLIPPER SYSTEM CROSSES THE SOUTHERN APPALACHIANS LATE
TONIGHT. COLDER AIR WITH LINGERING LOW LEVEL MOISTURE THANKSGIVING.
HIGH PRESSURE FRIDAY/SATURDAY. ANOTHER SYSTEM SUNDAY NIGHT/MONDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
EVEN BETWEEN A MAJOR AND MINOR SYSTEM...IT CAN BE DIFFICULT.  A LOT
OF OUR ATTENTION WEDNESDAY EVENING WAS TO OUR AVIATION CONCERNS...
WITH LOW CEILINGS AND INTERMITTENT LOW VSBY.  IN THE WEAK WIND
FLOW...PATCHY DENSE FOG DID FORM WHERE THE AIR GOT SATURATED FROM
THE COASTAL STORM.  MEANWHILE...CLOUDS AND VSBY MUCH HIGHER OVER
SOUTHEAST OHIO...NORTHEAST KENTUCKY AND HTS VCNTY TONIGHT.

INCREASING MID LEVEL MOISTURE WAS SPREADING BACK ACROSS OUR SOUTHERN
COUNTIES BY 03Z...AS EVIDENT 88D BEAM RETURNS.

WE STILL HAVE THE WEAKENING 700-500 MB TROF AXIS PASSING BY 12Z
THURSDAY.  WE HAVE AN INCH OR TWO OF ELEVATION BASED LIGHT SNOW
POSSIBLE ACROSS THE HIGH TERRAIN OF OUR SOUTHERN COUNTIES...DURING
THE PREDAWN HOURS. YET...AGREE WITH OUR DAYSHIFTERS...STILL DID NOT
SEE AN IMMEDIATE NEED FOR ADVISORIES.

COLDER 850 MB AIR MOVES OUR WAY WHILE A LOT OF FOLKS ARE FEASTING ON
TURKEY.  AS A RESULT...SOME LIGHT ACCUMULATIONS ARE EVEN POSSIBLE
INTO THURSDAY NIGHT OVER THE MOUNTAIN COUNTIES.

NO SIGNIFICANT CHANGES MADE TO TEMPERATURE OR POP GRIDS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
HANGING ON TO SOME POPS FOLLOWING THE CLIPPER TYPE SYSTEM TO START
THE SHORT TERM...THAN HAVE SOME ENHANCEMENT THURSDAY AFTERNOON AND
THURSDAY NIGHT AS UPPER TROUGH PASSES AND COLDER AIR OOZES IN.
MOISTURE QUICKLY MOVES OUT THURSDAY NIGHT AS HIGH PRESSURE NOSES IN
FROM THE SW. A WEAK WARM FRONT PASSES TO THE WEST AND BRINGS SOME
CLOUDS LATE FRIDAY INTO FRIDAY NIGHT AS THE SURFACE HIGH SLOWLY
HEADS SOUTHEAST. NOT EXPECTING ANY PRECIP FROM THE WARM FRONT.
SATURDAY WILL WARM BACK TO NEAR NORMAL WITH SOUTH TO SOUTHWEST FLOW.

BLENDED IN RAW CONSENSUS FOR LOWS. GOING A TOUCH COOLER THAN
PREVIOUS FORECAST IN THE HIGHER TERRAIN THURSDAY NIGHT...AND THEN
GOING WITH A NON DIURNAL ABOVE 3500 FT FRIDAY NIGHT. BLENDED IN THE
MAV FOR HIGHS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
GENERALLY USED THE ECMWF ENSEMBLE MEAN FOR THE FORECAST...WITH A BIT
OF THE GFS BLENDED IN. HIGH PRESSURE SLIDES EASTWARD SATURDAY NIGHT
AND SUNDAY...PROVIDING A SOUTHERLY FLOW. NEXT FRONTAL BOUNDARY
PUSHES INTO THE REGION SUNDAY NIGHT INTO MONDAY. HANDLING OF THIS
FRONT BEYOND MONDAY BECOMES A BIT MURKY. SOME MODELS DEVELOP A WAVE
ALONG THE FRONT FOR TUESDAY WHILE OTHERS PUSH THE FRONT TO THE SOUTH
AND DISSOLVE IT. WILL KEEP SOME SMALL POPS TUESDAY INTO WEDNESDAY
DUE TO THE UNCERTAINTY...BUT CONFIDENCE IS LOW.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AREA BETWEEN FEATURES THIS WEDNESDAY EVENING.   LOWERED CONFIDENCE
TO LOW BECAUSE OF THE AREA AROUND CRW TO CKB THAT SAW THEIR AIR MASS
SATURATED FROM THE EAST COAST STORM...BUT NOW THE CLOUDS WERE
THINNING.  A FEW BREAKS MAY DEVELOP THIS EVENING...WHICH COULD CAUSE
THE VSBY TO DROP TEMPORARILY INTO THE 1 TO 3 MILE RANGE.  OTHERWISE
STILL IFR AND LIFR OVER WV MOUNTAINS DUE TO LOW STRATUS AND LINGERING
FLURRIES...DRIZZLE...OR FREEZING DRIZZLE 00Z TO 12Z.

MEANWHILE...WHERE AIR DID NOT SATURATE ON WEDNESDAY...IN SE OHIO AND
NE KY...CEILINGS HIGHER...MOSTLY 3 TO 5 THSD FT BKN.

MID DECK ASSOCIATED WITH THE SECONDARY CLIPPER LIKE SYSTEM ADVANCING
QUICKLY OVER THE LOWER CLOUDS 03Z TO 06Z.  LIGHT SNOW REFORMING OVER
SOUTHERN COUNTIES...MOSTLY S OF CRW...HAVE BKW TAF SITE AFFECTED THE
MOST DURING THE PREDAWN HOURS.

CLIPPER SYSTEM EXITS AFTER 12Z...WITH BOUNDARY LAYER WINDS FINALLY
INCREASING AND HELPING TO LIFT THE CEILINGS IN WV BETWEEN 15Z TO
18Z.  HAVE CEILINGS MOSTLY 2 TO 3 THSD FT BKN/OVC WITH SCATTERED
SNOW SHOWERS IN THE COLDER AIR AT 850 MBS 18Z THU TO 00Z FRIDAY.
VSBY OCCASIONALLY NEAR 3 MILES IN SNOW SHOWERS MOSTLY CNTRL AND NRN
WV DURG THAT 18Z TO 00Z PD.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...

FORECAST CONFIDENCE: LOW.

ALTERNATE SCENARIOS: VSBY MAY NOT DROP VCNTY CRW 00Z TO 03Z THIS
EVENING IF BREAKS IN CLOUDS DO NOT OCCUR.  VSBY OVER MOUNTAIN
COUNTIES...INCLUDING BKW...MAY BE MORE VARIABLE OVERNIGHT THAN
INDICATED.

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.

DATE                                                       THU 11/27/14
UTC 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
EST 1HRLY       21   22   23   00   01   02   03   04   05   06   07   08
CRW CONSISTENCY  L    L    L    H    H    H    M    M    H    H    H    H
HTS CONSISTENCY  M    M    H    H    H    H    M    M    M    M    M    M
BKW CONSISTENCY  M    M    M    H    M    M    H    H    H    H    H    M
EKN CONSISTENCY  H    H    H    M    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    M    M    M    M    M    H    H    H    H    H    H
CKB CONSISTENCY  H    H    M    H    H    H    H    H    H    H    H    H

AFTER 00Z FRIDAY...
IFR CONDITIONS IN SNOW SHOWERS MAY LINGER OVERNIGHT THURSDAY NIGHT OVER
WV MOUNTAINS.

&&

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

&&

$$
SYNOPSIS...RPY/MZ/26
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...RPY
AVIATION...KTB










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