-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 121841
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
230 PM EDT WED MAR 12 2014

.SYNOPSIS...
STRONG COLD FRONT WHIPS EAST OF THE MOUNTAIN COUNTIES BY
LATE AFTERNOON. IN ITS WAKE...GUSTY WINDS AND TURNING MUCH COLDER.
COLD THURSDAY...BUT WARMING FRIDAY. WEAKER COLD FRONT SATURDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
PREFRONTAL CONVECTION BAND EXITING MOUNTAIN COUNTIES 19Z TO 20Z.
STRONG COLD AIR ADVECTION WITH STRONG PRESSURE RISES THROUGH 00Z.
PRESSURE RISES ON THE ORDER OF ABOUT 8 TO 10 MB/3 HOURS. CONTINUING
THE WIND ADVISORY THAT WE POSTED YESTERDAY...FOR THE PERIOD NOON
TODAY TO MIDNIGHT TONIGHT.

AN EXAMPLE OF THE COLD AIR ADVECTION...THE 850 MB TEMPERATURE ON THE
12Z NAM WAS PLUS 7 C AT 18Z THEN MINUS 10C BY 00Z FOR CRW. THAT IS
17 DEGS CELSIUS IN 6 HOURS.  SURFACE TEMPERATURE AT HTS WENT FROM 59
TO 42 IN ONE HOUR BETWEEN 17Z AND 18Z.

THE TRANSITION FROM RAIN SHOWERS...TO DRIZZLE...TO SNOW SHOWERS
BEGINNING IN SOUTHEAST OHIO CURRENTLY...HAVE REACHING OUR FAR SW
22Z/23Z.

THINKING THE NAM A BIT OVERDONE ON THE SNOW ACCUMULATIONS OVERNIGHT
IN OUR MOUNTAINS...STILL THINKING MOSTLY 2 TO 4 INCHES OUR CENTRAL
MOUNTAINS...WITH MOSTLY AN INCH OR LESS THROUGH THE LOWLANDS...WITH
AN 1 OR 2 POSSIBLE IN NORTH CENTRAL WV AND FAR NORTHERN SOUTHEAST
OHIO.

WILL HOLD ONTO THE WINTER WEATHER ADVISORY IN THE MID OHIO VALLEY
WHERE OUR CRITERIA IS LOWER THAN NORTH CENTRAL WV.  BUT SEE NO BIG
REASON TO EXPAND THE WINTER WEATHER ADVISORY.

NO MAJOR CHANGES TO TEMPERATURE.  DID TAKE THE MINIMUM TEMPERATURE
FOR ELEVATIONS AOA 4 THSD FT TO AOB ZERO FOR 12Z/13Z THURSDAY.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
CHANGES TO THE SHORT TERM INCLUDE A MUCH QUICKER ENDING TO THE LOW
END POPS AFTER 12Z THURSDAY. NAM SHOWS THAT MOISTURE IN THE LOW
LEVELS WILL JUST NOT HANG ON LONG ENOUGH TO SUPPORT ANY DECENT
UPSLOPING CONDITIONS PAST THIS TIME...SO ESSENTIALLY END THEM BY
AROUND 15Z THURSDAY.

BY 12Z THURSDAY...850MB TEMPERATURES WILL HAVE COMPLETELY
CRASHED...WITH A -22C THERMAL TROUGH OVER THE NORTHEAST MOUNTAINS.
THIS RESULTS IN WIDESPREAD TEMPERATURES THAT WILL REMAIN BELOW
FREEZING ACROSS THE CWA THURSDAY...WITH ONLY A FEW LOCATIONS IN THE
WARMER SOUTHERN AND WESTERN ZONES ECLIPSING THE 32F MARK. CLOUDS
CLEAR QUICKLY...SO A DECENT SUN ANGLE WILL HELP IN THIS DEPARTMENT.

AS QUICKLY AS THE COLD AIR CRASHED IN...WARM AIR ADVECTION MAKES A
COMEBACK AND WILL SEE THOSE 850MB TEMPERATURES CLIMBING BACK ABOVE
0C BY 18Z FRIDAY. SOUTHWEST SURFACE FLOW BRINGS TEMPERATURES BACK
INTO THE 50S...WITH A FEW LOCATIONS PUSHING 60F. THIS WARM FLOW
ASSOCIATED WITH A SURFACE LOW TRAVERSING THE NORTHERN GREAT LAKES
WILL HAVE ENOUGH INFLUENCE FOR SOME VARIABLE MID LEVEL CLOUD COVER
INTO THE WEEKEND. A WEAK COLD FRONT WILL SINK IN FRIDAY NIGHT AND
STALL INTO SATURDAY...WITH MEAGER FORCING/MOISTURE. ONLY CARRYING
SOME LOW END CHANCE POPS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
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 /19Z WEDNESDAY THROUGH MONDAY/...
FRONT QUICKLY MOVING EAST WITH NARROW LINE OF CONVECTION. HAVE LINE
PASSING EAST OF EKN-BKW LINE AROUND 19Z. IN STRONG COLD AIR
ADVECTION AND STRONG PRESSURE RISES 18Z TODAY THROUGH 00Z
THURSDAY...THE STRONGEST WIND GUSTS WILL BE POST FRONTAL...MOSTLY
19Z TODAY THROUGH 00Z THURSDAY...BUT LINGERING OVER MOUNTAINS THROUGH
04Z.

CEILINGS LOWER IN THE COLDER AIR...HAVE WIDESPREAD CEILINGS 5 HND TO
1 THSD FT 20Z THROUGH 04Z THURSDAY WITH FREQUENT VSBY AOB 3 MILES IN
LIGHT RAIN/DRIZZLE CHANGING TO LIGHT SNOW.

MOUNTAIN RIDGES OBSCURED IN LOW CLOUDS FROM FROM AROUND 20Z TODAY
THROUGH 06Z THURSDAY.

CONDITIONS IMPROVING IN THE OHIO VALLEY COUNTIES AFTER 03Z WITH
CEILINGS LIFTING INTO THE 2 TO 3 THSD FT BKN TO OVC AND VSBY 5 MILES
IN LINGERING LIGHT SNOW SHOWERS.  THAT IMPROVING TREND SHIFTING
EAST...REACHING THE MOUNTAINOUS COUNTIES AFTER 12Z THURSDAY.

CONFIDENCE REMAINS AT MEDIUM TIMING...IN TRYING TO TIME THE IMPROVING
CONDITIONS FROM WEST TO EAST LAST TONIGHT INTO THURSDAY MORNING.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING OF IMPROVING CONDITIONS FROM WEST TO
EAST 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
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    L    L    L    M    M    M    L    L    L    L
HTS CONSISTENCY  H    H    M    M    M    L    L    L    L    L    M    M
BKW CONSISTENCY  M    M    H    M    M    M    M    M    M    M    M    L
EKN CONSISTENCY  H    M    L    M    M    M    M    M    M    M    M    L
PKB CONSISTENCY  H    H    M    M    M    M    M    L    L    L    L    L
CKB CONSISTENCY  M    H    H    L    M    M    M    M    M    M    M    L

AFTER 18Z THURSDAY...
IFR POSSIBLE SUNDAY IN RAIN OR SNOW MAINLY SOUTHERN WEST VIRGINIA...
MOUNTAIN COUNTIES...AND SOUTHWEST VIRGINIA

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR WVZ005>011-
     013>020-024>040-046-047.
     WINTER WEATHER ADVISORY UNTIL 2 AM EDT THURSDAY FOR WVZ009-010-
     019.
OH...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR OHZ066-067-075-
     076-083>087.
     WINTER WEATHER ADVISORY UNTIL 2 AM EDT THURSDAY FOR OHZ066-067-
     075-076-084.
KY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR KYZ101>103-105.
VA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VAZ003-004.

&&

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