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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 040907
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
350 AM EST WED DEC 4 2013

.SYNOPSIS...
ANOTHER WARM FRONT CROSSES TODAY. SLOW MOVING COLD FRONT FOR
THURSDAY AND FRIDAY WITH ABUNDANT PRECIPITATION. BRIEF HIGH
PRESSURE SATURDAY. ANOTHER WET SYSTEM SUNDAY AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
WARM AIR ADVECTION REALLY GETS CRANKING TODAY ON STRENGTHENING SW
FLOW ALOFT. WILL BE TRACKING ANOTHER WARM FRONTAL BOUNDARY POISED
TO CROSS THIS AFTERNOON. THERE WILL ALSO BE SOME UPPER AIR SUPPORT
IN CONJUNCTION WITH THIS FEATURE WHICH MAY PROVIDE FOR A FEW LIGHT
RAIN SHOWERS TODAY...MAINLY ACROSS SE OH...WHERE SOME CHANCE POPS
WERE MAINTAINED FROM PREVIOUS FORECAST. OTHERWISE...WILL WE TRYING
TO RID THE AREA OF CLOUDS TODAY WHICH MAY PROVE FUTILE UNTIL THIS
AFTERNOON...ESPECIALLY ACROSS SE OH AND ALSO ALONG THE E SLOPES IN
THE N MOUNTAINS ON LOW LEVEL SE UPSLOPE FLOW.

WARM AIR ADVECTION CONTINUES IN EARNEST TONIGHT AS LOW LEVEL JET
AROUND 50 KTS APPROACHES LATE TONIGHT AHEAD OF THE COLD FRONT.
THIS IN CONJUNCTION WITH TIGHTENING OF THE ISOBARS WILL PROVIDE
FOR A BREEZY NIGHT ACROSS PORTIONS OF SE OH AND ACROSS THE
MOUNTAINS. THINK ENOUGH OF AN INVERSION SETS UP ACROSS THE WV
LOWLANDS TO KEEP THE PUFF OFF UNTIL PREDAWN. THINK SOME 15 TO 20
KT GUSTS ARE POSSIBLE...PARTICULARLY ON THE HIGHER HILLTOPS IN SE
OH AS WELL AS IN THE MOUNTAINS. FRONT LOOKS TO BE STILL W OF A
LINE FROM CLE TO CMH TO CINCY AT 12Z. AS SUCH TRIED TO DELAY THE
POPS AS LONG AS POSSIBLE WITH SOME HELP FROM A DOWNSLOPING
COMPONENT NEAR THE SURFACE. STILL...BRING IN HIGH CHANCE AND LOW
LIKELY ACROSS PORTIONS OF SE OH BY SAID TIME.

FOR TEMPS...HARD TO FIGURE THE GUIDANCE GIVEN FLIP FLOP
VERIFICATION FOR HIGHS THE PAST COUPLE OF DAYS BETWEEN THE MET AND
THE MAV. WILL OPT FOR A BLEND...CLOSE TO IN HOUSE LOCAL MOS
GUIDANCE. DID HEDGE TOWARD WARMER MET ACROSS THE I79 CORRIDOR AND
TYGART VALLEY WHERE SOME COMPRESSIONAL WARMING EFFECTS FROM
DOWNSLOPING SE LOW LEVEL FLOW SHOULD GIVE THOSE AREAS A BOOST.
HAVE MOST PLACES IN THE 62 TO 65F RANGE OUTSIDE OF THE HIGH
TERRAIN. HAVE GENERALLY 50S IN THE HIGHER TERRAIN EXCEPT TYGART
VALLEY WHERE AFOREMENTIONED LOCAL EFFECTS SHOULD GET TEMPS TO PAST
THE 60 DEGREE MARK. TONIGHT...ROLLED ON THE WARMEST SIDE OF THE
ENVELOPE ALONG AND W OF THE OH RIVER WHERE BL PUFF SHOULD KEEP
THINGS MIXED. THE W LOWLANDS AND SE OH MAY BE HARD PRESSED TO DIP
MUCH BELOW THE UPPER 50S. FURTHER E SOME DECOUPLING EARLY MAY
ALLOW TEMPS TO SNEAK BELOW 50 IN SHELTERED LOCATIONS...ESPECIALLY
IN THE MOUNTAIN VALLEY. OVERALL THOUGH A VERY MILD NIGHT
RELATIVELY SPEAKING.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
-- Changed Discussion --
ECMWF/CANADIAN AND NAM ARE ALL IN FAIRLY GOOD AGREEMENT WITH THE
TIMING OF THE COLD FRONT AND PLACEMENT OF THE ASSOCIATED RAIN SHIELD
WITH THE FRONT AND WAVES MOVING ALONG THE FRONT. THE GFS IS A BIT
FURTHER SOUTH WITH THE RAIN SHIELD. WILL GO WITH THE MAJORITY AND
EDGE BACK POPS IN THE SOUTHEAST ON THURSDAY IN ADVANCE OF THE FRONT.
MODELS ARE ALSO IN FAIRLY GOOD AGREEMENT ON THE EXITING
PRECIPITATION FRIDAY NIGHT...SO WILL REMOVE POPS ON SATURDAY. MODELS
STILL SHOWING LOTS OF PRECIPITATION WITH THIS SYSTEM. WILL HAVE TO
CONTINUE TO MONITOR FOR A FLOOD THREAT. SECOND ROUND ON SUNDAY AND
MONDAY MAY BE THE BIGGER THREAT IN THAT REGARD...AS THE FIRST SYSTEM
WILL SATURATE THE GROUND AND FILL THE RIVERS.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
ALL THE MODELS POINT TO A VERY UNSETTLED WEATHER PATTERN THIS PERIOD
WITH THE POTENTIAL FOR HEAVY RAINS. ONE UPPER LEVEL TROUGH LIFTS
OUT OF THE LONG WAVE TROUGH CENTERED OVER THE WEST CENTRAL PART OF
THE NATION FRIDAY...AND AN EVEN STRONGER UPPER LEVEL TROUGH LIFTS
OUT ACROSS THE AREA SUNDAY AND MONDAY. FIRST UPPER SYSTEM ALREADY
WILL HAVE PUSHED A STRONG COLD FRONT TO JUST EAST OF THE MOUNTAINS
THURSDAY NIGHT...WITH A WAVE OF LOW PRESSURE RIDING UP THE FRONT AND
SPREADING A LARGE OVERRUNNING PRECIP SHIELD OVER OUR AREA FRIDAY.
TEMPERATURES WILL GENERALLY HOLD STEADY TO SLOWLY FALLING FRIDAY
BEHIND THE FRONT. EVEN FOR THE MOST AGGRESSIVE GFS MODEL IN BRINGING
COLD AIR IN FRIDAY...THE BOUNDARY LAYER IS SLOW TO COOL OFF TO BELOW
FREEZING UNTIL LATE IN THE AFTERNOON IN THE WEST. THUS...WE KEEP A
COLD RAIN FOR MOST OF THE DAY FRIDAY. THERE MAY BE HEAVY RAIN FRIDAY
     AND POTENTIAL WATER PROBLEMS WILL BE CLOSELY LOOKED AT.
HOWEVER...AS THE RAIN WILL BE OF A STEADY AND PROLONGED NATURE...WE
MAY JUST BE ABLE TO HANDLE THE RAINFALL FROM THE THURSDAY/FRIDAY
SYSTEM. THEREAFTER...EXPECT RAIN CHANGING TO SNOW FROM THE WEST
FRIDAY NIGHT...WITH MOST PLACES HAVING SNOW BY LATER FRIDAY NIGHT. THE
SYSTEM WILL BE PULLING OUT FRIDAY NIGHT...SO WHEN THE CHANGEOVER TO
SNOW OCCURS...ONLY MINOR ACCUMULATIONS OF AN INCH OR TWO COULD BE
EXPECTED.

SATURDAY PROVIDES A BRIEF BREAK IN THE ACTION WITH DRY BUT QUITE
COLD TEMPERATURES. TEMPERATURES WILL DROP WELL DOWN INTO THE 20S
FRIDAY NIGHT AND STRUGGLE TO REACH FREEZING ON SATURDAY.

FOR SUNDAY...THERE ARE TIMING DIFFERENCES AS TO WHEN PRECIP WILL
ACTIVATE AGAIN AS THE NEXT UPPER TROUGH AND FRONT APPROACH. WILL
TEND TO BE SLOW IN REINTRODUCING POPS LATER SATURDAY NIGHT...PER
GENERAL MODEL CONSENSUS. HOWEVER...BY SUNDAY ANOTHER ROUND OF
POTENTIALLY HEAVY PRECIP WILL BE ARRIVING AND LASTING INTO MONDAY.
IN THIS CASE...THE ASSOCIATED SURFACE LOW WILL LIFT TO THE WEST OF
OUR AREA SO THAT WARM AIR WILL RAPIDLY STREAK NORTHWARD. WE EXPECT
THERE MAY BE A BRIER PERIOD OF LIGHT WINTRY MIX SUNDAY MORNING
BEFORE CHANGING TO ALL RAIN BY AFTERNOON AS TEMPERATURES RISE INTO
THE 40S. RAIN CONTINUES MONDAY AS THE ASSOCIATED FRONT SLOWS AND
ANOTHER WAVE OF LOW PRESSURE RIDES UP. WE WILL REALLY HAVE TO WATCH
POTENTIAL WATER PROBLEMS WITH THIS SYSTEM. FINALLY THINGS BEGIN TO
DRY OUT FROM THE WEST TUESDAY WITH COLDER AIR MOVING BACK IN FOR
TUESDAY NIGHT.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
MAINLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH VARYING
BASES AMID MID/HI CLOUDS ALONG WITH 4 TO 6 THSD FOOT CIGS. THERE
WILL BE A FEW EXCEPTIONS. SOME MVFR STRATUS MAY MOVE INTO NE KY
AND SE OH THIS MORNING...GIVING KHTS A FEW HRS OF MVFR CIGS THIS
MORNING. ALSO...MOIST SE FLOW JUST OFF THE SURFACE SHOULD LOWER
CIGS INTO LOW END MVFR THRU 12Z ALONG THE E SLOPES IN THE WV
MOUNTAINS...AFFECTING KBKW. SOME LOCAL IFR CIGS CANNOT BE RULED E
OF KBKW BUT THINK TERMINAL ITSELF STAYS MVFR. LOCAL DOWNSLOPING
EFFECTS FOR KEKN SHOULD KEEP THAT TERMINAL IN VFR.

SW FLOW STRENGTHENS HEADING INTO TONIGHT WITH LOW LEVEL JET ON
ORDER OF 50 KTS AT H85 APPROACHES AHEAD OF COLD FRONT LATE. WINDS
OUT OF S TO SSE CLOSE TO THE SURFACE WILL PREVAIL AND BECOME GUSTY
TONIGHT ACROSS THE HIGHER MOUNTAINOUS TERRAIN AND ALONG THE E
SLOPES TO INCLUDE KBKW WHERE 15 TO 20 KT GUSTS ARE POSSIBLE. THIS
MAY ALSO HOLD TRUE FOR SE OH. THINK ENOUGH OF AN INVERSION SETS UP
ACROSS WV LOWLAND TAF SITES TO KEEP PUFF OFF THE DECK UNTIL CLOSER
TO 12Z THU. OH RIVER SITES THOUGH TOUGH CALL THOUGH.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
     THURSDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: MVFR CEILING PLACEMENT AND TIMING MAY VARY
THROUGH MORNING FOR SE OH AND E SLOPE OF WV MOUNTAINS.

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                                   WED 12/04/13
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EST 1HRLY       01   02   03   04   05   06   07   08   09   10   11   12
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  M    L    L    L    L    L    M    L    M    M    H    H
EKN CONSISTENCY  H    H    H    M    M    L    L    M    M    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    M    H    H    H    H    H

AFTER 06Z THURSDAY...
IFR POSSIBLE IN RAIN THURSDAY NIGHT INTO FRIDAY NIGHT.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...JMV
AVIATION...30