Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 181743
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
143 PM EDT THU SEP 18 2014

.SYNOPSIS...
HIGH PRESSURE...CENTERED TO OUR NORTH...MOVING OFF NORTHEAST COAST
FRIDAY. COLD FRONT AROUND LATE SUNDAY INTO SUNDAY NIGHT..

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO CHANGES THIS MORNING TO THE FORECAST. AWAITING THE DISSOLUTION
OF THE FOG ONCE AGAIN IN THE CENTRAL WEST VIRGINIA LOWLAND
VALLEYS.

PREVIOUS DISCUSSION...
LOW STRATUS AND AREAS OF DENSE FOG WILL GRADUALLY LIFT AROUND 14Z
AT MOST PLACES. HIGH PRESSURE CENTERED TO OUR NORTH WILL PROVIDE
MOSTLY SUNNY SKIES BY MID TO LATE MORNING INTO THE AFTERNOON
HOURS. TEMPERATURES WILL BE COUPLE OF DEGREES WARMER THAN
YESTERDAYS REACHING NEAR NORMAL TEMPERATURES FOR THIS TIME OF THE
YEAR. DRY CONDITIONS WILL PREVAIL THROUGH THE PERIOD.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
QUIET PATTERN WILL CONTINUE IN THE SHORT TERM. BROAD UPPER TROUGHING
OVER THE NORTHEAST CONUS FRIDAY WILL GRADUALLY BREAK DOWN WITH ZONAL
FLOW SATURDAY AS ANOTHER UPPER TROUGH MOVES EASTWARD ACROSS THE
UPPER MIDWEST INTO THE GREAT LAKES. NO MAJOR CHANGES FROM PREV FCST
WITH LATEST DATA. SFC HIGH PRESSURE CENTERED TO THE NORTH AT THE
OUTSET OF THE PERIOD CONTINUES TO SHIFT EASTWARD OFF THE NEW ENGLAND
COAST BY 00Z SAT WITH RESULTANT BL WINDS SETTING UP OUT OF THE
SOUTHEAST. LLVL MOISTURE WILL BANK UP AGAINST THE EASTERN MOUNTAINS
AND HAVE CONTINUED A SLIGHT CHANCE OF SHOWERS IN THAT GENERAL AREA
AS SUCH...AGAIN WHICH PREV FCST HAD A GOOD HANDLE ON. LATEST NAM12
MOISTURE PROFILES HINT AT SOME POTENTIAL FOR CONVECTIVE SHOWERS
FURTHER WEST OVER THE CENTRAL WV LOWLANDS BUT AT THIS
POINT...MOISTURE AVAILABILITY AT AROUND THE 850MB-800MB LEVEL MAY BE
SOMEWHAT OVERDONE AS WELL AS THE CO-LOCATED INSTABILITY. THUS FOR
NOW...LEFT THE FORECAST DRY FOR ALL OF THE LOWLANDS. MAX TEMPS
GENERALLY UPPER 70S LOWLANDS STILL LOOK GOOD.

DRY WEATHER UNDER MOSTLY SUNNY/CLEAR TO PARTLY CLOUDY SKIES WILL
CONTINUE FRIDAY NIGHT AND SATURDAY WITH LESS LLVL MOISTURE
AVAILABLE. ONLY CHANGE OF ANY REAL SIGNIFICANCE WAS TO RAMP UP
TEMPS ON SATURDAY BY A GOOD 3-5 DEGREES FOR MUCH OF THE LOWLANDS.
TEMPS AT 925MB PROGGED AROUND 20C-22C SHOULD RESULT IN LOW 80S FOR
MANY LOCATIONS...A TREND WHICH IS ALSO BEARING OUT IN LATEST MOS
GUIDANCE. TEMPS WILL BE SLIGHTLY WARMER SAT NIGHT VERSUS FRI NIGHT
WITH SOUTH/SOUTHWEST WINDS AND INCREASING CLOUDS WITH AN APPROACHING
COLD FRONT MOVING INTO THE LOWER GREAT LAKES REGION BY 12Z SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
USED WPC THINKING WITH SOME MINOR TWEAKS. COLD FRONT WILL PUSH
SOUTHEAST OF THE MOUNTAINS SUNDAY NIGHT WITH HIGH PRESSURE TAKING
CONTROL BY MONDAY AFTERNOON. THE HIGH SHOULD BE IN CONTROL THROUGH
THE REMAINDER OF THE PERIOD...RESULTING IN DRY AND SEASONABLY COOL
TEMPERATURES.

WPC TEMPS LOOKED GOOD AND WERE GENERALLY USED.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
EXPECT OVERALL CLEARING THROUGH THE EVENING AS DIURNAL HEATING
WANES.

AFTER 00Z TONIGHT...THE MOUNTAINS WILL BE UNDER THE INFLUENCE MID
LEVEL CLOUDS AND SOUTHEAST FLOW AT THE SURFACE. THIS SHOULD BRING
CLOUDS INTO THE EKN AREA AND HALT THE FORMATION OF THE TYGART
VALLEY FOG FOR THAT TERMINAL. FURTHER SOUTH AT BKW...SOUTHEAST
FLOW BRINGS IFR CEILINGS LATE TONIGHT...LINGERING INTO FRIDAY WITH
DRIZZLE POSSIBLE. NAM BUFR SOUNDINGS WERE THE MOST USEFUL TOOL FOR
THE BKW TAF...SHOWING THE TIMING OF BOUNDARY LAYER SATURATION AND
THICKNESS OF THE SATURATED LAYER RESULTING IN DRIZZLE POTENTIAL
FRIDAY.

ELSEWHERE IN THE LOWLANDS...EXPECTING A LARGELY TYPICAL LATE
SUMMER NOCTURNAL FOG PATTERN. RELIED ON THE LAMP GUIDANCE FOR
TIMING OF IFR/LIFR VISIBILITIES.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: NAM MAY BE TOO AGGRESSIVE WITH THE EASTWARD
EXTENT OF THE UPSLOPING IFR CEILINGS AT BKW. EKN FOG MAY NOT BEGIN
OR ERODE AT FORECAST TIME.

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    H    H    H    H    H    H    H    H    M    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    M    L    L
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z FRIDAY...
IFR CONDITIONS POSSIBLE SUNDAY IN SHOWERS/STORMS.

&&

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

&&

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







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