612  
FXUS61 KRLX 290720  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
320 AM EDT TUE JUL 29 2014  
   
SYNOPSIS
 
 
COOLER AND DRIER AIRMASS THROUGH MID WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
UPPER LEVEL TROUGH AXIS WILL KEEP CONDITIONS COOL AND VERY MILDLY  
UNSETTLED OVER THE MIDDLE OHIO VALLEY TUESDAY. NAM GIVING A WEAK  
TROUGH AXIS EMBEDDED WITHIN THE CYCLONIC FLOW...AND WITH ADEQUATE  
MOISTURE THROUGH 700MB...A FEW SHOWERS AND WEAK THUNDERSTORMS ARE  
POSSIBLE AGAIN TODAY.  
 
DEWPOINTS WILL KEEP DROPPING SLOWLY AS THE ARRIVAL OF THE CANADIAN  
AIRMASS BECOMES COMPLETE. LOWLAND 70S AND MOUNTAIN 60S PROMINENT  
AGAIN...WITH LOWS IN THE 50S AND 40S RESPECTIVELY TONIGHT. CLOUD  
COVER COULD MAKE THIS ON THE TRICKY SIDE AND MAY ULTIMATELY NEED TO  
ADD A COUPLE DEGREES. LEANED ON THE MAV...WHICH WAS THE BETTER  
PERFORMING GUIDANCE LAST NIGHT.  
 

 
   
SHORT TERM /WEDNESDAY THROUGH FRIDAY/
 
 
AN UPPER DISTURBANCE WILL ROTATE AROUND THE MEAN EASTERN U.S. UPPER  
TROUGH WEDNESDAY...KEEPING TEMPERATURES ON THE COOL SIDE AND MAY  
BRING SOME LIGHT SHOWERS MOSTLY IN THE NORTH. ALL THE  
MODELS SHOW A HEALTHY RH FIELD WITH THIS FEATURE ACROSS THE NORTH.  
BUT WITH LACK OF A LOW LEVEL FOCUSING MECHANISM...THE SHOWERS WILL  
TEND TO BE DIURNAL...WIDELY SCATTERED...AND LIGHT. SLOWLY  
RISING HEIGHTS WITHIN THE MEAN UPPER TROUGH AND MODERATING SURFACE  
HIGH PRESSURE WILL BRING MOSTLY DRY WEATHER AND A SLOW WARMING TREND  
THURSDAY. LOOK FOR TEMPERATURES TO GET BACK INTO MAINLY THE LOWER  
80S BY THURSDAY...WHICH IS STILL BELOW NORMAL.  
 
BY FRIDAY...ALTHOUGH WEAKER...THE MEAN EASTERN U.S. UPPER TROUGH  
SHARPENS UP A BIT...AS UPPER RIDGING OVER THE WESTERN ATLANTIC OCEAN  
RETROGRADES. SURFACE HIGH PRESSURE BY THIS TIME WILL HAVE SHIFTED  
FAR ENOUGH EAST TO INCREASE LOW LEVEL MOISTURE ON A SOUTH TO  
SOUTHEAST FLOW. THE INCREASED INSTABILITY WILL BRING A GRADUAL  
INCREASE IN THE CHANCE FOR SHOWERS...MAINLY ON EAST FACING SLOPES OF  
THE MOUNTAINS WHERE MODEST UPSLOPE FORCING INCREASES. INCREASED  
CLOUDS FRIDAY WILL HOLD TEMPERATURES DOWN IN THE LOWER 80S...BUT  
HUMIDITY WILL INCREASE.  
 

 
   
AVIATION /07Z TUESDAY THROUGH SATURDAY/
 
 
VERY DIFFICULT AVIATION FORECAST. OBSERVATIONS ALREADY WITH A  
HISTORY OF BOUNCING AND WILL CONTINUE TO DO SO AS PATCHY MID LEVEL  
CLOUDS ADVECT THROUGH THE TERMINALS. HAD TO SET THE CONDITIONS ON  
THE WIDER SIDE BECAUSE OF THIS...BUT HAVE TRIED TO CONFINE THEM TO  
CONDITIONS THAT HAVE ALREADY OCCURRED WITH THE HOPE OF ACHIEVING  
SOME CONSISTENCY. IN THE END...CLEARER SKIES COULD ALLOW FOR  
VALLEY FOG...ONLY TO DISSIPATE IN CEILINGS AS CLOUD COVER  
INCREASES.  
 
ISOLATED CONVECTION POSSIBLE AGAIN ON TUESDAY.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...  
 
FORECAST CONFIDENCE: MEDIUM.  
 
ALTERNATE SCENARIOS: OBSERVATIONS WILL LIKELY BOUNCE...AND USED  
TEMPOS MORE LIBERALLY THAN DESIRED.  
 
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 TUE 07/29/14  
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19  
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15  
CRW CONSISTENCY H H L L L L M M M M M M  
HTS CONSISTENCY L L L L L L M M M M M M  
BKW CONSISTENCY H M M H H H H H M M M M  
EKN CONSISTENCY L L L L L L L M M M M M  
PKB CONSISTENCY M L L L L M M M M M M M  
CKB CONSISTENCY M M L L M M M M M M M M  
 
AFTER 06Z WEDNESDAY...  
NO SIGNIFICANT IFR CONDITIONS EXPECTED.  
 

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

 
 

 
SYNOPSIS...JMV/26  
NEAR TERM...26  
SHORT TERM...JMV  
LONG TERM...JS  
AVIATION...26  
 
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