Area Forecast Discussion
Issued by NWS Charleston, WV

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS61 KRLX 240840
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
340 AM EST WED DEC 24 2014

.SYNOPSIS...
COLD FRONT BRINGS GUSTY WINDS AND SHOWERS TODAY. CHRISTMAS DAY
STARTS COLD...CLOUDY...AND WINDY. HIGH PRESSURE CHRISTMAS NIGHT
INTO FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SFC LOW TO DEVELOP AND TRACK NORTH OF THE TN VALLEY AND INTO MI
TODAY. ACCOMPANYING COLD FRONT TO SWING THROUGH LATER THIS AFTERNOON
AND THIS EVENING...REACHING OH RIVER BY AROUND 20Z AND EXITING EAST
OF THE CWA AROUND 02Z. SOUNDING PROFILES INDICATE FAIRLY STABLE
ATMOSPHERE OUT AHEAD OF FRONT AND TWEAKED POPS BACK FOR
TODAY...PRIOR TO FRONT ARRIVAL. HOWEVER...INVOF FRONT THERE IS
ENOUGH SHALLOW INSTABILITY AND PLENTY OF MOISTURE IN PLACE FOR LOW
TOPPED SHOWERS WITH A FEW LIGHTNING STRIKES. BOTH GFS AND NAM12
SWING A 50-60KT 85H JET CORE NORTH ALONG THE OH RIVER WITH THE FRONT
AND JUST BEHIND. ANY CONVECTION IN PLACE COULD EASILY SEE THESE
WINDS BEING TRANSLATED TO SFC. BETWEEN THE MODELS...THE GFS IS
TRENDING FASTER WITH PROGRESSION OF FRONT ACROSS THE CENTRAL
APPALACHIANS AND THIS IS THE PREFERRED SOLUTION.  COULD SEE
BAROCLINIC BOUNDARY GETTING HUNG FOR A SHORT PERIOD ALONG THE
EASTERN EXTENT OF THE CWA FOR A FEW HOURS THOUGH LATER THIS
EVENING.  EXPANDED WIND ADV FURTHER TO THE EAST TO COVER CKB THIS
EVENING...MAINLY TO COVER RIDGETOPS AND WINDS WITH AND JUST BEHIND
THE FRONT AS IT MAKES ITS WAY THROUGH.

MAX TEMPS TODAY WILL BE WELL ABOVE NORMAL AHEAD OF THE FRONT WITH
DEEP SOUTHERLY FLOW IN PLACE. TEMPS WILL DROP OFF DURING THE
OVERNIGHT HOURS WITH CAA IN PLACE BRING A PERIOD OF WINTRY MIX BY
CHRISTMAS MORNING.


&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
MODELS CONTINUE TO SHOW THAT 850 MB TEMPERATURES BEHIND THE FRONT
ARE MARGINAL FOR AUTO CONVECTION...ALTHOUGH PLENTY OF LOW LEVEL
MOISTURE AND UPSLOPE WINDS EXIST. THEREFORE...WILL KEEP POPS IN THE
CHANCE CATEGORY.

HIGH PRESSURE BUILDS IN FOR THURSDAY NIGHT AND FRIDAY.

LOTS OF SPREAD IN THE ARRIVAL OF THE NEXT SYSTEM OVER THE WEEKEND.
THE GENERAL TREND IS SLOWER HOWEVER...SO WILL REMOVE POPS FOR
FRIDAY NIGHT.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE EXITING TO THE EAST EARLY IN THE LONG TERM. MODELS
THEN HAVE SOME DISCREPANCIES GOING FORWARD. ECMWF HAS HAD A STRETCH
OF RATHER LACKLUSTER PERFORMANCE IN THE LONG TERM RECENTLY...SO
WHILE NOT DISCOUNTING IT COMPLETELY...DID PUT MORE WEIGHT ON THE GFS
WHILE BLENDING. THIS BRINGS A MOISTURE STARVED COLD FRONT THROUGH
SATURDAY...AND THEN A SECOND SURFACE WAVE RIDES UP THE FRONT SUNDAY
INTO MONDAY. GFS HAS THIS WELL SOUTH AND EAST OF CWA...WITH THE
EASTERN THIRD OF THE CWA BEING CLIPPED BY THE NW FRINGE OF THE QPF
FIELD. FOR COMPARISON...THE ECMWF IS MUCH FARTHER WEST WITH THE
SECOND WAVE.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD MVFR CONDITIONS...BECOMING MOSTLY IFR OVER THE WV MOUNTAINS
TOWARD MORNING WITH AREA OF MOISTURE IN PLACE. DEVELOPING SURFACE
LOW WILL MOVE NORTH FROM TN RIVER VALLEY INTO CENTRAL MI BY 00Z.
IN RESPONSE SURFACE GRADIENTS WILL TIGHTEN AND COLD FRONT PASSAGE
WILL TAKE PLACE LATE THIS AFTERNOON. WITH SOME DRY SLOTTING THIS
AFTERNOON AHEAD OF THE FRONT IMPROVED CIG AND VISBY VALUES
SLIGHTLY FROM MORNING VALUES. THEN EXPECT A ROUND OF GUSTY SHOWERS
AND ISOLD TO SCT THUNDERSTORMS WITH THE COLD FRONT.

SFC WINDS TO INCREASE TO 20KTS OR GREATER THIS AFTERNOON WITH
30KTS LIKELY ON THE RIDGETOPS. A FEW STRONGER GUSTS CAN BE
EXPECTED WITH ANY CONVECTION INVOF FRONT AS IT TRACKS
THROUGH...REACHING THE CRW-PKB LINE BY ABOUT 00Z.


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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: IFR CONDITIONS MAY BE MORE WIDESPREAD THIS
MORNING IN AREAS OF HEAVIER RAIN AND FOG. TIMING OF CHANGING
CONDITIONS WITH THE DRY SLOT AND THEN THE COLD FRONT MAY VARY THIS
AFTERNOON.

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 12/24/14
UTC 1HRLY       08   09   10   11   12   13   14   15   16   17   18   19
EST 1HRLY       03   04   05   06   07   08   09   10   11   12   13   14
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    M    M
BKW CONSISTENCY  M    M    M    M    H    M    H    M    H    M    M    M
EKN CONSISTENCY  H    L    H    H    L    H    H    H    H    H    H    H
PKB CONSISTENCY  M    M    M    M    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    M    M    M    M    H    H    H    H    H    H    H

AFTER 06Z THURSDAY...
IFR IN CLOUDS POSSIBLE IN THE HIGHER ELEVATIONS OF THE MOUNTAINS WED
NT INTO THU.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND ADVISORY FROM NOON TODAY TO 10 PM EST THIS EVENING FOR
     WVZ005>011-013>019-024>026.
     WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 10 PM EST THIS
     EVENING FOR WVZ020-028>032-038>040-046-047.
OH...WIND ADVISORY FROM NOON TODAY TO 10 PM EST THIS EVENING FOR
     OHZ066-067-075-076-083>087.
KY...WIND ADVISORY FROM NOON TODAY TO 10 PM EST THIS EVENING FOR
     KYZ101>103-105.
VA...NONE.

&&

$$
SYNOPSIS...KMC/RPY
NEAR TERM...KMC
SHORT TERM...RPY
LONG TERM...MZ
AVIATION...KMC







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.