Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 161433
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1033 AM EDT TUE SEP 16 2014

.SYNOPSIS...
BROAD HIGH PRESSURE BUILDS FROM THE WEST...AND STAYS IN CONTROL
INTO THE WEEKEND. COLD FRONT POSSIBLY TOWARD THE END OF THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LOW CLOUDS HANGING IN PLACE AND CONTINUING TO ADVECT FROM THE
NORTH. STILL THINK THERE WILL BE ENOUGH MIXING TO BEGIN TO ERODE
THE LOW LEVEL DECK AROUND 17-18Z. A FEW SPRINKLES LINGERING AS
WELL...AND LEFT THE SLIGHTS IN FOR NOW.

PREVIOUS DISCUSSION...
A BROAD HIGH PRESSURE APPROACHES FROM THE WEST TO PRODUCE A WEAK
NORTHERLY FLOW TODAY...BECOMING WEAKER FROM THE NORTHEAST
WEDNESDAY. MEANWHILE ALOFT...NEAR ZONAL FLOW IS NOTICED IN H5
CHARTS THROUGH WEDNESDAY. THEREFORE...EXPECT DRY AND COOL WEATHER
THROUGH THE PERIOD.

THE NEAR CALM FLOW AND MOSTLY CLEAR SKIES WILL ALLOW FOR DENSE FOG
FORMATION DURING THE PREDAWN HOURS WEDNESDAY MORNING.

USED THE NAMDNG5 WITH FEW ADJUSTMENTS FOR TEMPERATURES THROUGH THE
PERIOD.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TRANQUIL WEATHER WILL PERSIST IN THE SHORT TERM WITH HIGH PRESSURE
DOMINATING...WITH A GENERALLY DRY FORECAST THROUGHOUT. A COUPLE OF
DISTURBANCES PUSH THROUGH NW FLOW ALOFT WED NIGHT AND AGAIN THU.
HOWEVER...WITH VERY LITTLE LLVL MOISTURE TO WORK WITH AND A STOUT
NEAR-ISOTHERMAL CAP IN PLACE IN AND AROUND 750MB...ONLY AN INCREASE
IN FLAT CU IS EXPECTED ACROSS THE MOUNTAINS DURING THE DAY WED AND
OVER THE SOUTHERN PART OF THE FORECAST AREA WED NIGHT INTO THU.

THE ONLY CAVEAT TO THE COMPLETELY DRY FORECAST IN THE SHORT TERM MAY
COME IN THE HIGHEST PEAKS OF THE EASTERN MTS WED AFTERNOON. LATEST
NAM12 MODEL POINT SOUNDINGS INDICATE NEAR-SATURATED LOW LEVELS WITH
A MOISTURE DEPTH AND/OR CONVECTIVE LAYER DEPTH OF ABOUT 4KFT-5KFT
UNDERNEATH AFOREMENTIONED CAP AROUND 750MB...WITH A DECENT RIDGE TOP
CONVERGENCE SIGNATURE. IN FACT...CONSENSUS OF LATEST SHORT-TERM NWP
DEPICTS SOME QPF BTWN 18Z WED AND 00Z THU IN THAT GENERAL AREA AS
WELL AS AT LEAST SLIGHT CHANCE POPS. HOWEVER...WITH PWATS OF ONLY
AROUND 0.85IN AND WITH SUCH A SHALLOW MOISTURE DEPTH...BELIEVE THE
POPS AND PARTICULARLY THE QPF AMOUNTS TO BE OVERDONE AND HAVE KEPT
MEASURABLE POPS OUT OF THE FORECAST. DID ELECT TO INSERT A SLIGHT
CHANCE OF A SPRINKLE WED AFTERNOON...AGAIN ON THE HIGHEST PEAKS
MAINLY ABOVE 3KFT WITH THE POTENTIAL FOR A SPRINKLE OR TWO HERE. THE
ONLY OTHER ADJUSTMENT WAS TO PUT THIS SAME GENERAL AREA IN SOLID
PARTLY CLOUDY SKY COVER DURING THE AFTERNOON.

VERY LITTLE CHANGE FROM PREV FCST REGARDING TEMPERATURES...WITH
GENERAL LOWER 70S IN THE LOWLANDS AND UPPER 40S/LOWER 50S
LOWLANDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
FOR FRIDAY AND SATURDAY...USED A BLEND OF THE GFS...ECMWF...GFS
ENSEMBLE MEAN...AND ECMWF ENSEMBLE MEAN. THIS KEEPS THE AREA UNDER
HIGH PRESSURE WITH TEMPERATURES SLOWLY MODERATING SOME. FOR SUNDAY
INTO MONDAY...A COLD FRONT WILL PUSH THROUGH THE AREA. USED A BLEND
OF THE GFS ENSEMBLE MEAN AND THE ECMWF ENSEMBLE MEAN FOR FRONTAL
TIMING.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SFC OBSERVATIONS SUGGEST WEAK COLD FRONT STILL ACROSS THE SOUTHERN
COAL FIELDS OF WV THIS MORNING. LIGHT RAIN SHOWERS ARE EVIDENT IN
DOPPLER RADAR MOVING QUICKLY EAST. EXPECT THIS FRONT AND
ASSOCIATED PCPN TO MOVE EAST OF THE EASTERN MOUNTAINS BY MID
MORNING.

MEANWHILE...IFR CEILINGS WILL BE POSSIBLE OVER THE ELEVATED
TERRAIN...ESPECIALLY BKW THIS MORNING...WHILE MVFR CEILINGS WILL
BE POSSIBLE OVER THE REST OF SITES AT LEAST THROUGH MID MORNING.

BROAD SFC HIGH PRESSURE WILL BUILD FROM THE WEST TODAY...BRINGING
SOME CLEARING TO THE AREA THIS AFTERNOON. CONDITIONS SHOULD
IMPROVE TO VFR AREA WIDE BY NOON.

WITH NEAR CALM FLOW AND MOSTLY CLEAR SKIES...IFR RADIATION FOG IS
LIKELY TO DEVELOP OVERNIGHT TONIGHT AT MOST PLACES. CODED SUCH IFR
CONDITIONS IN THE EXTENDED PART OF TAFS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...

FORECAST CONFIDENCE: MEDIUM TO HIGH.

ALTERNATE SCENARIOS: CIGS MAY LAST LONGER THAN EXPECTED THIS
MORNING.

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       14   15   16   17   18   19   20   21   22   23   00   01
EDT 1HRLY       10   11   12   13   14   15   16   17   18   19   20   21
CRW CONSISTENCY  H    H    H    M    M    M    M    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    M    M    H    H    H    H    H    H
BKW CONSISTENCY  H    H    M    M    H    H    H    M    M    M    M    M
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    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    H    H    H    H    H    H

AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN DENSE VALLEY FOG EARLY WEDNESDAY MORNING.

&&

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

&&

$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...RPY
AVIATION...ARJ







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