968 
FXUS61 KRLX 281801
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
155 PM EDT TUE AUG 28 2012

.SYNOPSIS...
DRIER AIR OOZES SOUTH. HIGH PRESSURE BUILDS IN FOR WEDNESDAY INTO 
FRIDAY. THE REMNANTS OF ISAAC COULD BRING SHOWERS OVER THE LONG 
HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SEEMS LIKE THE BEST POSSIBILITY OF LATE DAY SHOWERS WILL BE SOUTH OF 
THE OLD FRONTAL CLOUD BAND...WHICH WOULD MAKE IT FROM THE WV/VA 
BORDER NEAR MCDOWELL COUNTY ON SOUTH INTO VA AND SE KY. SO WAS 
QUICKER IN LOWERING POPS VCNTY BKW.

12Z GFS AND NAM FORECAST SOUNDINGS BOTH SHOW LINGERING MOISTURE AT 3 
TO 6 THSD FT OVERNIGHT AS 850 TEMPERATURES TRY TO LOWER A DEGREE OR 
TOW.  THAT MOISTURE WAS MARGINAL FOR THE STRATOCUMULUS TO 
LINGER...AT LEAST IN PATCHES OVERNIGHT.  THIS WILL MESS WITH FOG 
FORMATION.  SINCE THE HEAVIEST RAIN WAS ONLY LESS THAN .2 OVERNIGHT 
LAST NIGHT...WILL LIMIT ANY FOG FOR A FEW HOURS MOSTLY 08Z TO 
12Z...MOSTLY MOUNTAIN VALLEYS AND SOUTHERN WV COAL FIELDS.  

NO MAJOR CHANGES TO WEDNESDAY.  SHOULD STILL HAVE SOME FLAT 
STRATOCUMULUS FORM AFTER 15/16Z.  TRIED TO STAY ON HIGH SIDE OF MOS 
GUIDANCE ON TEMPERATURES DUE TO THE DRIER GROUND.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MODELS AGREE UPPER HIGH STRONGLY DOMINATES THE OHIO VALLEY MID AND 
LATE WEEK. IT SLIDES EASTWARD INTO THE ATLANTIC BY THE WEEKEND...
AS THE REMAINS OF ISSAC APPROACH FROM THE WEST. THIS WILL BRING 
QUITE DRY AND WARMER CONDITIONS FOR THE REMAINDER OF THE WORKWEEK. 
WITH THE DRY AIR...LOOK FOR A WIDE RANGE IN DIURNAL 
TEMPERATURES...WITH GENERALLY ABOVE NORMAL DAY TIME TEMPERATURES 
UNDER ABUNDANT SUNSHINE. CLOUDS BEGIN TO INCREASE FRIDAY FROM 
ISSAC...BUT PRECIPITATION WILL HOLD OFF UNTIL AT LEAST FRIDAY NIGHT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MAIN QUESTION FOR THE LONG TERM LIES WITH THE TRACK OF ISAAC...AND 
IF/WHEN PRECIP COULD MAKE IT INTO THE FORECAST AREA. STAYED CLOSE TO 
HPC GUIDANCE...BUT DID SLOW ONSET JUST A LITTLE...GOING MIDDLE OF 
THE ROAD BETWEEN ECMWF WHICH DOES NOT SHOW MUCH PRECIP UNTIL 
SATURDAY AFTERNOON AND THE GFS WHICH IS QUITE A BIT 
FASTER...BRINGING PRECIP IN BY FRIDAY AFTERNOON.

GOING WITH THIS TREND...EXPECT THE WARMING TREND OF THE SHORT TERM 
TO CONTINUE INTO FRIDAY AFTERNOON...BUT THEN WITH MORE CLOUDS FOR 
THE WEEKEND...SHOULD SEE COOLER AFTERNOON TEMPERATURES SATURDAY 
THROUGH MONDAY. BUT ALSO WITH MORE CLOUDS...WILL NOT SEE AS MUCH 
RADIATIONAL COOLING AT NIGHT...SO EXPECTING OVERNIGHT LOWS WELL 
ABOVE NORMAL.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
DEW POINTS AT 17Z...STARTING TO FALL WITH MIXING...WHILE WEAK 
SURFACE FRONT DROPPING INTO SOUTHWEST VIRGINIA. LOWER MORNING CLOUDS 
LIFTING WITH THE MIXING.

HAVE MOSTLY 3 TO 5 THSD FT AGL SCATTERED TO BROKEN CLOUDS.  SOME
VSBY NEAR 5 MILES IN HAZE IN SOUTHWEST VIRGINIA AND EXTREME SOUTHERN 
WV.  A FEW SHOWERS POSSIBLE IN SOUTHWEST VIRGINIA THROUGH 00Z. 

MAIN DILEMMA IS THE COVERAGE AND DENSITY OF FOG 06Z TO 12Z 
WEDNESDAY...RESULTING IN THE MEDIUM FORECAST CONFIDENCE. 12Z MODEL 
FORECAST SOUNDINGS SHOW LINGERING MOISTURE OVERNIGHT AS 850 
TEMPERATURES TRY TO COOL A DEGREE OR TWO.  SO PATCHES OF 3 TO 6 THSD 
FT STRATOCUMULUS MAY LINGER OVERNIGHT...COMPOUNDING THAT FOG 
FORMATION.

IN THE VALLEYS FROM EKN TO CRW TO THE SOUTHERN COAL FIELDS...TRIED 
TO FORM SOME AREAS OF IFR AND LIFR IN FOG...BUT LIMITED IN DURATION 
DUE TO THE DRY GROUND/VEGETATION...MAINLY FOR 08Z TO 12Z.

SCATTERED FLAT STRATOCUMULUS 4 TO 6 THSD FT FORMING AFTER 15Z 
WEDNESDAY.       


FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
     
FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: NO WIDESPREAD IFR COVERAGE AND DENSITY OF FOG 
06Z TO 12Z IN COULD BE MORE OR LESS...DEPENDING ON PATCHES OF 
LINGERING CLOUDS.   

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  M    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  M    M    M    M    M    M    H    H    H    H    H    H
EKN CONSISTENCY  M    M    M    M    M    M    M    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 WEDNESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.

&&

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

&&

$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...JMV
LONG TERM...MZ
AVIATION...KTB