543  
FXUS61 KRLX 270037  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
837 PM EDT FRI AUG 26 2016  
   
SYNOPSIS
 
 
UPPER LEVEL HIGH PRESSURE IN PLACE WITH HOT AND HUMID WEATHER  
THROUGH THE WEEKEND. NORTHWEST FLOW WITH SEVERAL UPPER LEVEL  
DISTURBANCES NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH SATURDAY/
 
 
AS OF 830 PM FRIDAY...  
SATELLITE AND RADAR IMAGES SHOW MOSTLY CLEAR SKIES WITH NO PCPN.  
HIGH RESOLUTION MODELS SHOW DRYING TENDENCY TONIGHT. EXPECT THE  
LOWER ATMOSPHERE TO DECOUPLE PROVIDING CALM FLOW. THESE CONDITIONS  
ARE CONDUCIVE TO DENSE FOG FORMATION. HOWEVER, ONLY EXPECT DENSE  
VALLEY FOG AT EKN AND HTS OVERNIGHT. FORECAST REMAINS ON TRACK.  
 
PREVIOUS DISCUSSION BELOW...  
AS OF 138 PM FRIDAY...  
COMBINATION OF TEMPERATURES IN THE UPPER 80S AND LOWER 90S...  
COUPLED WITH HIGH HUMIDITY VALUES...RESULTED IN HEAT INDICES TO  
EXCEED 100 DEGREES IN A FEW LOCALES.  
 
LATEST MODELS SUGGEST THERE COULD BE A FEW SHOWERS/STORMS THIS  
AFTERNOON. HOWEVER...THE MODELS ARE NOT CONSISTENT WITH THE  
LOCATION WHERE THE STORMS MAY FORM. CURRENT THINKING IS THAT HIGH  
PRESSURE...AT THE SURFACE AND ALOFT...SHOULD PRECLUDE THE  
DEVELOPMENT OF STORMS AND HAVE KEPT POPS BELOW 15.  
 
WITH THE LOSS OF SUNSHINE...TEMPERATURE SHOULD SLOWLY FALL AND ANY  
DIURNAL CLOUDS WILL DISSIPATE. BELIEVE RIVER VALLEY FOG/MIST WILL  
ONCE AGAIN BE POSSIBLE.  
 
ANY FOG THAT DOES FORM SHOULD DISSIPATE SHORTLY AFTER SUNRISE ON  
SATURDAY. PREVIOUS FORECAST MATCHES FAIRLY WELL WITH LATEST  
MODELS AND HAVE DECIDED TO KEEP SLIGHT CHANCE POPS IN THE  
MOUNTAINS FOR SATURDAY AFTERNOON.  
 
LATEST TEMPERATURE GUIDANCE FOR LOWS TONIGHT IS FAIRLY CLOSE AND  
WAS FOLLOWED. AS FAR AS HIGH TEMPERATURES FOR SATURDAY...LATEST  
GUIDANCE IS WARMER THAN PREVIOUS NUMBERS AND HAVE BUMPED HIGHS UP  
A DEGREE OR SO.  
 
COMBINATION OF THESE TEMPERATURES AND CONTINUING HIGH HUMIDITY  
VALUES SUGGEST THERE MAY BE A MORE WIDESPREAD AREA OF HEAT INDICES  
EXCEEDING 100 DEGREES. THERE MAY BE A NEED FOR A HEAT ADVISORY FOR  
SATURDAY AFTERNOON.  
 

 
   
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/
 
 
AS 220 PM FRIDAY...  
 
THE AREA REMAINS UNDER AN UPPER LEVEL RIDGE THROUGH MONDAY. THERE  
MAY BE ENOUGH INSTABILITY TO POP A MAINLY AFTERNOON  
SHOWER/THUNDERSTORM WITH BEST CHANCES IN THE MOUNTAINS.  
 

 
   
LONG TERM /TUESDAY THROUGH FRIDAY/
 
 
AS 220 PM FRIDAY...  
 
ON OR ABOUT TUESDAY, THE UPPER LEVEL RIDGE THAT HAS BEEN LINGERING  
OVER THE REGION BEGINS TO FLATTEN ALLOWING A MORE ZONAL  
PROGRESSION. BY THURSDAY AN UPPER LEVEL TROUGH DIGS OVER THE MID  
ATLANTIC. WITH PROGRESSIVE FLOW, LEFT AT LEAST A SCHC TO CHC POPS  
MOST PERIODS. BEST CHANCE FOR A FROPA WOULD PROBABLY BE WED  
EVENING THOUGH NOT MUCH QPF WITH ANY OF THE WEAK FRONTS THAT CROSS  
THE AREA.  
 

 
   
AVIATION /01Z SATURDAY THROUGH WEDNESDAY/
 
 
AS OF 800 PM FRIDAY...  
 
00Z SATURDAY THROUGH 00Z SUNDAY...  
WIDESPREAD VFR CONDITIONS WILL PREVAIL AT LEAST THROUGH 06Z. AREAS  
OF PATCHY RIVER VALLEY FOG ARE EXPECTED AFTER 06Z MAINLY AT EKN  
AND HTS FROM 06Z TO 1230Z UNDER MOSTLY CLEAR SKIES.  
 
THERE WILL BE LESS CLOUDS THAN LAST NIGHT. THIS COULD BRING MVFR  
CEILINGS AT OTHER SITES BUT CONFIDENCE RUNS LOW. ANY FOG THAT  
FORMS SHOULD QUICKLY DISSIPATE AFTER 12Z...WITH VFR CONDITIONS  
PREVAILING THROUGH THE END OF THE PERIOD.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...  
 
FORECAST CONFIDENCE: MEDIUM.  
 
ALTERNATE SCENARIOS: EXTENT OF DENSE FOG IS IN QUESTION OVERNIGHT.  
 
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 SAT 08/27/16  
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11  
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07  
CRW CONSISTENCY H H H H H H M M M M M L  
HTS CONSISTENCY H H H H H H H H H M M L  
BKW CONSISTENCY H H H H H H H H H H M L  
EKN CONSISTENCY H H H H M M M M L L L M  
PKB CONSISTENCY H H H H H H M M M M M L  
CKB CONSISTENCY H H H H H H H M M M M L  
 
AFTER 00Z SUNDAY...  
IFR CONDITIONS IN MORNING RIVER VALLEY FOG POSSIBLE THROUGH THE  
WEEKEND...DEPENDING ON CLOUD COVER.  
 

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

 
 

 
SYNOPSIS...JSH/JW  
NEAR TERM...JSH/ARJ  
SHORT TERM...JW  
LONG TERM...JW  
AVIATION...ARJ  
 
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