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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 120631
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
209 AM EDT WED MAR 12 2014

.SYNOPSIS...
SPRING LIKE EVENING. STRENGTHENING LOW PRESSURE CENTER CROSSES
WEDNESDAY. GUSTY WINDS AND TURNING MUCH COLDER WEDNESDAY AFTERNOON
AND WEDNESDAY NIGHT. WARMING FRIDAY. WEAKER COLD FRONT SATURDAY.

&&

.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...

FORECAST ON TRACK.

830 PM UPDATE...

CLEANED UP SOME OF THE GRIDS THIS EVENING FOR A MORE OPTIMISTIC
FORECAST. STILL EXPECT SHRA TO BREAK OUT ALONG APPROACHING WARM
FRONT BY 06Z...WITH GREATEST THREAT OF THESE MEASURING OUT ALONG
AND W OF OH RIVER. KEPT SCHC THUNDER IN AS WELL. A GOOD CHUNK OF
CWA SHOULD BE IN WARM SECTOR BY 12Z WITH GREATEST POPS REMAINING
ALONG AND W OF THE RIVER. OVERALL...A VERY MILD EVENING ESPECIALLY ON THE
HILLS AND RIDGES WITH PUFF OF WIND.

TIMING OF FRONT FROM DAY SHIFT STILL LOOKS GOOD. DO FEEL A
CONVECTIVE BAND WITH FRONT WILL ROLL THROUGH...GAINING STEAM AS IT
GETS E OF THE RIVER. SPC STILL HAS E HALF OF CWA IN SLIGHT RISK.
ABRUPT CHANGE ON STRONG WIND GUSTS AS FRONT PASSES WITH SWITCH TO
SHSN WITHIN 3 HRS FOLLOWING FROPA. STILL ON TARGET FOR 1-2 INCHES
SE OH AND N WV LOWLAND AREAS CLOSE TO THE RIVER BY 00Z. SO
ESSENTIALLY GOING FROM THUNDERSTORMS TO STRONG WIND GUSTS AND A
SWITCH TO SHSN IN A MATTER OF A FEW HRS WITH FRONTAL PASSAGE.

PREVIOUS DISCUSSION BELOW...
A NICE SPRING LIKE EVENING PICTURES. TRIED TO HAVE TEMPERATURES
BOTTOM OUT BETWEEN 03Z TO 06Z...BEFORE STEADY IN THE EAST...AND
RISING IN THE WEST BEFORE THE RAIN ARRIVES.

THE FIRST SHOT OF RAIN WHIPS THROUGH 08Z TO 15Z...COULD NOT RULE OUT
AN EMBEDDED THUNDERSTORM...MOSTLY IN SOUTHEAST OHIO...WITH THIS
INITIAL SHOT OF RAIN.

TRIED TO PAINT A BRIEF BREAK IN SOUTHERN COUNTIES BEFORE THE COLD
FRONT WHIPS THROUGH. HAVE THE FRONT NEARING A CKB-CRW AT 18Z
WEDNESDAY.  SO BEST CHANCE FOR THUNDER ALONG FRONT WAS FURTHER EAST
DURING THE 18Z TO 20Z PERIOD.

WAS A BIT FASTER WITH THE COOLING ON WEDNESDAY...BUT ONLY BY AN HOUR
OR TWO.  AS A RESULT...HAVE MOSTLY 1 TO 2 INCHES OF SNOW IN THE
BACKLASH IN SOUTHEAST OHIO INTO MID OHIO VALLEY.  WHERE ADVISORY
CRITERIA IS ONLY 2 INCHES (1.5 INCHES ROUNDED UP) POSTED A WINTER
WEATHER ADVISORY. OF COURSE...SNOW AMOUNTS COULD BE JUST AS HIGH OR
HIGHER IN THE COUNTIES WHERE WINTER WEATHER ADVISORY CRITERIA IS
HIGHER...SUCH AS CENTRAL WV MOUNTAIN COUNTIES.

ALSO...WITH SUCH RAPIDLY COOLING IN THE LOW LEVELS...ALSO POSTED A
WIND ADVISORY THROUGH THE OUR 49 COUNTY AREA. OF COURSE...THINKING
THE STRONGEST GUSTS ARE POST FRONTAL. FOR EXAMPLE...THE 850 MB
TEMPERATURE AT CRW DROPS FROM +9C AT 18Z WEDNESDAY TO MINUS 12C AT
00Z THURSDAY.  THAT`S A 21C DROP IN 6 HOURS...QUITE IMPRESSIVE.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
-- Changed Discussion --
12Z MODEL RUNS DIDNT INITIALIZE THE POSITION OF DEVELOPING TROUGH
OVER THE NORTHERN PLAINS VERY WELL..PLACING THE VORTMAX OVER THE
NORTHERN PLAINS A LITTLE TOO FAR NORTH...AND THE WEAK SURFACE FRONT
ACROSS THE DELMARVA WAS POSITIONED FARTHER WEST IN THE
MODELS...GIVEN THIS DISCREPANCY CHOSE A BLEND OF GFS/NAM/EURO WITH
SLIGHT EMPHASIS ON 00Z ECMWF THAT SHOWED BETTER CONTINUITY...SHORT
TERM BEGINS WITH EXITING COLD FRONT MOVING EAST ACROSS EASTERN MTNS
IN THE EVENING...COLD AIR FILTERS IN QUICKLY BEHIND THE FRONT WITH
850MB TEMPS DROPPING 20C IN 12HRS ACROSS THE OHIO RIVER FROM 00Z
THURS TO 12Z WED...SNOWFALL IN THE SHORT TERM WILL BE LIGHT IN THE
WAKE OF THE COLD FRONT...HIGHER ELEVATIONS IN NORTHEAST COUNTIES MAY
SEE AN ADDITIONAL INCH OF SNOW AFTER SUNSET WEDNESDAY ENDING
SOMETIME SOON AFTER MIDNIGHT...POST FRONTAL WINDS WILL REMAIN STRONG
AND A WIND ADVISORY HAS BEEN ISSUED AND WILL EXPIRE AT MIDNIGHT
WEDNESDAY...WITH WIND GUSTS POTENTIALLY BETWEEN 40-50MPH ESPECIALLY
IN THE MOUNTAINS.

FAST MOVING UPPER LEVEL TROUGH EXITING TO THE EAST
ALLOWS AMPLIFIED RIDGE TO BUILD ACROSS THE OHIO VALLEY/MID ATLANTIC
LATER IN THE DAY THURSDAY...SURFACE HIGH OVER THE SOUTHEAST RESULTS
IN SURFACE WINDS SHIFTING FROM NORTHWEST TO SOUTHWEST AND WARM AIR
STARTS TO BUILD BACK IN OUT OF THE TENNESSEE VALLEY...AFTER TOPPING
OUT IN THE LOW TO MID 30S FRO MOST OF US ON THURSDAY...TEMPS WILL
BOUNCE BACK INTO THE LOW 50S FRIDAY.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
USED A BLEND OF THE GEFS MEAN AND THE ECWMF ENSEMBLE MEAN. THIS
PUSHES A COLD FRONT THROUGH FRIDAY NIGHT AND SATURDAY. THE PATTERN
THEN STAYS ACTIVE SUNDAY THROUGH TUESDAY WITH MULTIPLE SYSTEMS
POSSIBLY AFFECTING THE REGION. CONFIDENCE IS LOW IN THESE PERIODS
DUE TO THE LARGE SPREAD BETWEEN MODELS.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
06Z WEDNESDAY THRU 06Z THURSDAY...
WARM FRONT THIS MORNING FOLLOWED BY A STRONG AND VERY FAST MOVING
COLD FRONT TODAY...WITH STRONG NORTHWEST WINDS BEHIND IT...

CEILINGS AOA 8000 FEET TO START WITH A FEW SPRINKLES WEST OF THE
OHIO RIVER THRU 09Z WEDNESDAY. WARM FRONTAL SHRA SPREADING FROM
SOUTHWEST TO NORTHEAST 09Z TO 14Z...BUT STILL REMAINING MOSTLY LOW
END VFR CEILINGS AND VSBY. AFTER THE INITIAL BAND OF RAIN...MAY BE A
LULL IN WEST VIRGINIA FOR 2 TO 4 HOURS BEFORE THE ARRIVAL OF THE
ASSOCIATED COLD FRONT. HAVE THE COLD FRONT REACHING OHIO RIVER
AROUND 15Z...NEAR A CKB TO CRW LINE AROUND 18Z...AND TO THE
MOUNTAINS BY 22Z. CHANCE OF A THUNDERSTORM ALONG FRONT...ESPECIALLY
EAST OF THE OHIO RIVER AFTER 15Z. WIDESPREAD RAIN SHOWERS ALONG AND
BEHIND FRONT WITH MVFR TO IFR CEILINGS AND VSBY. A QUICK SWITCH TO
SHSN WITHIN 2-3 HOURS FOLLOWING FROPA...WITH CIGS AND VSBY LOWERING
INTO IFR. IMPROVING RAPIDLY TO MVFR FROM WEST TO EAST AFTER
00Z...WITH LINGERING SNOW SHOWERS.

NORTHWESTERLY WIND GUSTS INCREASE IN WAKE OF THE COLD FRONT...WITH
GUSTS OF 30 TO 40 KNOTS FOR ALL SITES...SLOWLY DIMINISHING FROM WEST
TO EAST AFTER 00Z.

CONFIDENCE DROPPED TO MEDIUM TRYING TO TIME ANY LULL WEDNESDAY
MORNING...BETWEEN INITIAL SHOT OF RAIN AND THE FRONT.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING OF THE FRONTAL PASSAGE MAY VARY SLIGHTLY
ON WEDNESDAY.

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 03/12/14
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    M    M
HTS CONSISTENCY  H    H    H    M    H    H    H    H    M    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    M    H    H    L    L    L    L    L
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L

AFTER 06Z THURSDAY...
LINGERING IFR IN BACKLASH SNOW SHOWERS AND STRONG WINDS MAINLY
MOUNTAINS THROUGH 12Z THURSDAY.
-- End Changed Discussion --

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
WV...WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR
     WVZ005>011-013>020-024>040-046-047.
     WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 2 AM EDT
     THURSDAY FOR WVZ009-010-019.
OH...WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR
     OHZ066-067-075-076-083>087.
     WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 2 AM EDT
     THURSDAY FOR OHZ066-067-075-076-084.
KY...WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR
     KYZ101>103-105.
VA...WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR
     VAZ003-004.
-- End Changed Discussion --

&&

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