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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 301820
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
219 PM EDT WED JUL 30 2014

.SYNOPSIS...
COOL...DRY AIRMASS HANGS ON THROUGH THURSDAY. HIGHER TEMPERATURES
AND HUMIDITY BEGINNING FRIDAY WILL LEAD TO CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE WEEKEND...ESPECIALLY IN THE MOUNTAINS.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHOWERS AND THUNDERSTORMS FORMING IN CENTRAL OHIO EARLY THIS
AFTERNOON...IN RESPONSE TO AN UPPER LEVEL S/W TROUGH THERE...WILL
MOVE ESEWD ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING.  NAM12
HAS NEAR TERM MODEL SUPPORT ON THIS IDEA.  HAVE SCT COVERAGE BUT MAY
HAVE TO BUMP UP PER DEVELOPMENT UPSTREAM.

THE WEATHER SETTLES DOWN WITH LESS CLOUD AND LOW LEVEL MOISTER LATER
TONIGHT AND THU SAVE FOR THE POST-RAIN EFFECTS OVERNIGHT TONIGHT.
IT AND THE CLEAR...CALM CONDITIONS THAT WILL ENSUE BEHIND THE AXIS
OF CONVECTION SHOULD ALLOW DENSE VALLEY FOG TO FORM ESPECIALLY AS WE
ARE NEARING IF NOT ENTERING FOG SEASON.  A NICE DAY IS ON TAP FOR
THU ONCE THE MORNING FOG IS GONE.

A SOUTHERN STREAM UPPER LEVEL FEATURE MAY BRING CONVECTION INTO SW
VA AS THU DRAWS TO A CLOSE THOUGH.

TEMPERATURES LOOKED CLOSE TO LATEST BIAS CORRECTED GUIDANCE ON LOWS
TONIGHT AND STRAIGHT UP GUIDANCE ON HIGHS THU...AS H85 VALUES
CLIMBING UP TO 14C SUPPORT AT LEAST LOWER 80S LOWLANDS.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
GENERAL MODEL AGREEMENT ON A WEAK BUT SHARPENING UPPER TROUGH OVER
THE EASTERN THIRD OF THE NATION...AS THE BERMUDA HIGH IN THE WESTERN
ATLANTIC EXPANDS WESTWARD. A DRY AND STILL RATHER MILD THURSDAY IS
EXPECTED WITH SURFACE HIGH PRESSURE OVER THE AREA. THE HIGH SHIFTS
EAST BY FRIDAY...ALLOWING WARMER AND MUCH MORE HUMID AIR TO RETURN
ON SOUTH TO SOUTHEASTERLY FLOW. THIS IN COMBINATION WITH UPPER
DISTURBANCES ROTATING AROUND THE UPPER TROUGH WILL BRING INCREASING
CHANCES FOR SHOWERS AND STORMS. THE BIG QUESTION IS HOW FAR WEST
WILL THESE DISTURBANCES...AND HENCE THE PRECIPITATION SHIELD...TRACK
AS THEY RIDE UP THE EASTERN SIDE OF THE UPPER TROUGH. GENERAL
CONSENSUS...WITH THE NAM A WESTERN OUTLIER...KEEPS MOST OF THE
PRECIPITATION THIS PERIOD IN THE MOUNTAINS AND EAST AS AN INVERTED
SURFACE TROUGH FORMS EAST OF THE MOUNTAINS. WILL HAVE HIGH POPS
MOUNTAINS FRIDAY ONWARD...WITH MUCH LOWER POPS WEST OF THE
MOUNTAINS. HIGH TEMPERATURES WILL STILL BE BELOW NORMAL THIS
PERIOD...IN THE LOWER 80S...BECAUSE OF THE WIDESPREAD CLOUDS
EXPECTED.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SHOWERS AND THUNDERSTORMS INCREASE IN COVERAGE FRIDAY NIGHT AND INTO
SATURDAY AS A LOW MOVES INTO THE AREA FROM THE SOUTHWEST. INCREASED
POPS TO HIGH CHANCE/LOWER LIKELIES IN THIS TIME FRAME
UNSETTLED WEATHER WILL CONTINUE FOR MUCH OF THE EXTENDED PERIOD...AS
ADDITIONAL UPPER LEVEL ENERGY DROPS SOUTHEAST INTO THE
MIDWEST...DEEPENING THE UPPER TROUGH ACROSS THE AREA...AND KEEPING
THE WEATHER ON THE COOL AND UNSETTLED SIDE. DRIER WEATHER WILL
FINALLY SETTLE IN TOWARDS EARLY TO MID NEXT WEEK AS THE UPPER TROUGH
PUSHES OFF TO THE EAST...AND SURFACE HIGH PRESSURE BUILDS IN.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
LINGERING LOW LEVEL MOISTURE MAY STILL LEAD TO MVFR CIGS THIS
AFTERNOON ALTHOUGH VFR WILL PREVAIL MOST OF THE TIME.

AN UPPER LEVEL DISTURBANCE WILL BRING AN AXIS OF SCATTERED SHOWERS
AND THUNDERSTORMS ACROSS THIS AFTERNOON INTO THIS EVENING.  TAFS MAY
NEED AMENDED FOR THUNDER AND MVFR OR WORSE CONDITIONS IF IT APPEARS
A THUNDERSTORM WILL TRACK OVER AN AIRPORT.  OTHERWISE THE VCTS / CB
GROUPS DEFINE THE TIME BRACKETS FOR THE DIFFERENT AIRPORTS.

CLEARING IN THE WAKE OF THIS SYSTEM WILL ALLOW DENSE VALLEY FOG TO
FORM OVERNIGHT TONIGHT.  ONCE THE FOG BURNS OFF THU MORNING...THE
DAY WILL FEATURE NEITHER MORNING CU NOR THUNDERSTORMS...SO VFR IS
FCST.

LIGHT SW SFC FLOW WILL BECOME W TO NW ONCE THE AXIS OF SCATTERED
CONVECTION MOVES THROUGH.  A THUNDERSTORM CAN BRING GUSTS UP TO 25
KTS.  THE SFC FLOW WILL BECOME CALM TONIGHT AND THEN LIGHT W TO SW
ON THU.  FLOW ALOFT WILL REMAIN LIGHT W.

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

FORECAST CONFIDENCE: MEDIUM TO HIGH.

ALTERNATE SCENARIOS: MVFR STRATOCU MAY OR MAY NOT POP UP AGAIN THIS
AFTERNOON.  A THUNDERSTORM COULD DIRECTLY IMPACT AN AIRPORT.  THE
TIMING AND EXTENT OF FOG OVERNIGHT INTO EARLY THU MORNING MAY VARY
FROM FORECAST.

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    H    H
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    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 18Z THURSDAY...
NO SIGNIFICANT IFR CONDITIONS EXPECTED.

&&

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

&&

$$
SYNOPSIS...KMC/JMV
NEAR TERM...TRM
SHORT TERM...JMV
LONG TERM...SL
AVIATION...TRM