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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 161812
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
212 PM EDT SUN MAR 16 2014

.SYNOPSIS...
LOW PRESSURE BRINGS A WINTER STORM THIS AFTERNOON AND TONIGHT. A
WEAK COLD FRONT CROSSES ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
130 AM UPDATE...
FCST LARGELY ON TRACK WITH PRECIPITATION MOVING INTO THE AREA.
FZRA AT HTS BUT PL AT WARNUCK TO THE W AND LGT SN IN LIBERTY TO THE
NE...SN HERE AT RLX.

1030 AM UPDATE...
FCST LARGELY ON TRACK WITH THE COLD AIR ON THE MOVE FROM THE
N...AND THE MOISTURE ON THE MOVE FROM THE S.

PREV DISCN...
ALL EYES ON YET ANOTHER HIGH IMPACT WINTER STORM...

THERE IS GOOD AGREEMENT ON OVERALL SYNOPTIC PATTERN AS A
WHOLE...BUT THE DEVIL IS IN THE DETAILS. THIS IS ESPECIALLY TRUE
REGARDING N EXTENT OF PRECIP SHIELD AND WHERE INTENSE NARROW
MESO SCALE BAND OF HEAVY SNOW SETS UP. BELIEVE THE KEY IS THE
ADVECTION S OF COLDER AIR FROM THE N...PARTICULARLY THE LOWER
DEWPOINTS FOR TODAY. INITIALLY THOUGHT GFS WAS TOO FAR N WITH QPF
INTO SE OH BUT AFTER LOOKING AT 03Z SREF AND 06Z NAM ROLLING
IN...THERE IS NOW BETTER AGREEMENT ON QPF AXIS AND AMOUNTS. AFTER
INTERROGATING FRONTOGENETIC FORCING MECHANISMS AND
DEFORMATION...BELIEVE THERE WILL BE A INTENSE BUT NARROW MESO SCALE
BAND OF SNOW THAT SETS UP ACROSS PORTIONS OF THE CWA THIS EVENING.
THERE ARE SUBTLE DIFFERENCES WITH PLACEMENT OF THIS BUT A
CONSENSUS IS EMERGING ALONG AND ESPECIALLY N OF A LINE FROM HTS-
CRW-SUM. SUSPECT WARNING CRITERIA AMOUNTS WILL BE MET WITHIN THIS
NARROW ZONE ESPECIALLY ONCE E OF I79 CORRIDOR. ENOUGH CONFIDENCE
TO UPGRADE NICHOLAS/BRAXTON/WEBSTER CO TO WARNINGS BASED ON 12 HR
CRITERIA. STILL A LITTLE UNCERTAINTY ACROSS THE C LOWLANDS
ESPECIALLY WITH MODELS TRYING TO PUT DOWN A COUPLE INCHES BEFORE
SUNSET...WHICH THIS TIME OF YEAR IS HARD TO ACCOMPLISH. WILL KEEP
ADVISORIES IN PLACE FOR THOSE AREAS AND LET DAY SHIFT REASSESS.
DID EXPAND THE ADVISORY FOR REST OF NE KY AND LAWRENCE/GALLIA OH
BASED ON MODEL CONSENSUS AND SREF PROBS. THINK RAIN WILL HANG ON
ACROSS THE COAL FIELDS UNTIL LATE WITH CHANGEOVER TO SNOW ALSO
INVOLVING SOME SLEET. HAVE ONLY AROUND AN INCH DOWN THERE AND SW
VA.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MODELS SHOW TONIGHTS SYSTEM PULLING OFF TO THE EAST ON MONDAY. NAM
THEN DEVELOPS A SECOND WAVE AND PUSHES MOISTURE OVER THE FORECAST
AREA TUESDAY AND TUESDAY NIGHT. ECMWF/GFS AND CANADIAN ARE MUCH MORE
SUPPRESSED WITH THE WAVE...KEEPING IT MAINLY SOUTH AND EAST OF THE
REGION. WILL DISCOUNT THE NAM FOR NOW.

A COLD FRONT THEN PUSHES THROUGH ON WEDNESDAY. GFS AND CANADIAN ARE
FAIRLY SIMILAR ON TIMING...WHILE THE ECMWF LAGS A BIT. WILL GO WITH
THE GFS/CANADIAN COMBINATION FOR NOW SINCE THAT IS MOST CONSISTENT
WITH THE PREVIOUS FORECAST. DUE TO LIMITED MOISTURE AND
SUPPORT...WILL KEEP POPS IN THE CHANCE CATEGORY FOR NOW.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS A SURFACE HIGH PRESSURE EXITS NORTHEAST TUESDAY NIGHT...ANOTHER
LOW PRESSURE SYSTEM EMERGE FROM THE CENTRAL PLAINS AND TRACKS
NORTHEAST INTO THE GREAT LAKES REGION WEDNESDAY.

MODELS HAVE KEEP CONSISTENCY WITH THIS LOW PRESSURE SYSTEM FOR
COUPLE OF DAYS...BRINGING A BRIEF WARM FRONT LIFTING NORTH EARLY
WEDNESDAY MAINLY ACROSS SOUTHEAST OH. THE LOCAL AREA SHOULD REMAIN
IN THE WARM SECTOR...BRINGING WARMER TEMPERATURES GENERALLY IN THE
UPPER 50S...WITH SOME LOCATION REACHING THE LOWER 60S UNDER DEEP
SOUTHWEST FLOW. THE ASSOCIATED COLD FRONT CROSSES DURING THE DAY
WEDNESDAY INTO THE EVENING HOURS...TO EXIT THE AREA EARLY THURSDAY.
MODELS SHOW SIGNS THAT THE COLD FRONT WILL WEAKEN AS IT CROSSES THE
AREA. ADJUSTED POPS AND WEATHER...EXPECTING MAINLY RAIN SHOWERS ON
WEDNESDAY.

STILL SOME DIFFERENCES IN TIMING BETWEEN THE GFS AND ECMWF BUT THEY
ARE CLOSING INTO A BETTER AGREEMENT. LARGE UNCERTAINTY IN ECMWF
ENSEMBLES MEMBERS FOR TEMPERATURES. ALTHOUGH SOME SPREAD IS NOTICED
ON THE GFS ENSEMBLES WITH THE UPPER TROUGH...THERE STILL SOME
CONSENSUS AMONG MOST OF ITS MEMBERS. PREFERRED THE GFS SLOWER
SOLUTION AS THE ECMWF SEEMS TO CATCH UP WITH IT.
THEREFORE...INCREASED POPS TO LIKELY ALONG THE COLD FRONT ON
WEDNESDAY...SPREADING EAST WEDNESDAY NIGHT INTO EARLY THURSDAY.

GENERALLY USED HPC GUIDANCE. TWEAKED DOWN TEMPS FRIDAY DAY 7 TO
COMPROMISE WITH NEIGHBORING OFFICES.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
LOW PRESSURE TRACKING S OF THE AREA TONIGHT...WITH ARCTIC HIGH
PRESSURE TOP THE N...BRINGS WINTRY PRECIPITATION.

VFR CONDITIONS ABOUT TO DROP QUICKLY THIS AFTERNOON WITH WINTRY
PRECIPITATION MOVING INTO THE AREA FROM S TO N.  MAINLY SNOW N OF
THE HTS-CRW CORRIDOR WITH RAIN...FREEZING RAIN AND SLEET ALONG THE
CORRIDOR AND MAINLY RAIN S.  THIS TRANSITION ZONE WILL SHIFT SWD
ACROSS THE AREA THIS AFTERNOON AND TONIGHT...YIELDING ALL SNOW BY
EARLY MON MORNING.  THE PRECIPITATION SHOULD BE ALL SNOW IN THE
HTS-CRW CORRIDOR BY MID TO LATE AFTERNOON TODAY.  THE PRECIPITATION
TAPERS OFF NW TO SE MON MORNING...ENDING AS RAIN OR DRIZZLE FROM CRW
S BY MIDDAY MON.

WIDESPREAD MVFR CONDITIONS BY MID AFTERNOON S AND LATE AFTERNOON
N...WHERE IFR IN SNOW IS MOST LIKELY LATE THIS AFTERNOON THROUGH
THIS EVENING.  BEHIND THE SYSTEM...MVFR STRATUS WILL LINGER WELL
INTO THE DAY ON MON.

A STIFF E TO NE WIND INTO TONIGHT...E TO SE IN THE MOUNTAINS...WILL
GRADUALLY DIMINISH LATE TONIGHT AND MON.  LIGHT SE FLOW ALOFT
BECOMES MODERATE SE THIS EVENING...THEN LIGHT E TO NE OVERNIGHT
THROUGH MON MORNING.

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

FORECAST CONFIDENCE:  MODERATE.

ALTERNATE SCENARIOS: TIMING OF ONSET OF LOWER CIGS/VSBYS IN
PRECIPITATION...MAY VARY.  THE FCST DEPICTS A GENERAL TREND.

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
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  L    L    L    M    M    M    M    M    M    M    M    M
HTS CONSISTENCY  L    L    L    M    M    M    M    M    M    M    M    M
BKW CONSISTENCY  H    M    L    M    M    M    M    M    M    M    M    M
EKN CONSISTENCY  L    L    L    M    M    M    M    M    M    M    M    M
PKB CONSISTENCY  H    H    L    L    L    L    L    L    L    M    M    M
CKB CONSISTENCY  H    L    L    L    L    M    M    M    M    M    M    M

AFTER 18Z MONDAY...
NO WIDESPREAD IFR EXPECTED.
-- End Changed Discussion --

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
WV...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR WVZ005>008-
     013>018-024>027-029-030-035-036-039-040.
     WINTER STORM WARNING UNTIL 11 AM EDT MONDAY FOR WVZ028-037-038-
     046-047.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR OHZ086-087.
KY...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR KYZ101>103-
     105.
VA...NONE.
-- End Changed Discussion --

&&

$$
SYNOPSIS...RPY/30
NEAR TERM...TRM/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...TRM