343  
FXUS61 KRLX 300705  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
305 AM EDT SAT APR 30 2016  
   
SYNOPSIS
 
 
WARM FRONTAL SHOWERS INCREASE TODAY. MORE INSTABILITY SUNDAY WITH  
COLD FRONT SINKING SOUTHEAST SUNDAY NIGHT. DRIER MONDAY. WAVE  
PASSES TO THE SOUTHEAST TUESDAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
A WARM FRONT WILL GRADUALLY LIFT NORTH...BRINGING SCATTERED TO  
NUMEROUS SHOWER WITH EMBEDDED THUNDERSTORMS THIS AFTERNOON AND  
EVENING. HIGH RESOLUTION MODELS ARE IN AGREEMENT WITH THE ONSET OF  
PCPN OVER SOUTHERN WV AND NORTHEAST KY BY 18Z SATURDAY. PRECIPITABLE  
WATER ABOUT 1.25 INCHES...DESCENT DEEP LAYERED SHEAR ABOUT 45  
KNOTS...BUT LOW SFC CAPE WITH COMBINE TO PRODUCE MAINLY SHOWERS  
THROUGH TONIGHT.  
 
MODELS INDICATE H850 TEMPERATURES WILL BE AROUND 12C THROUGH THE  
PERIOD. TEMPERATURES WILL BE MILD DUE TO CLOUD COVER AND COOLING  
SHOWERS...GENERALLY IN THE LOWER 70S LOWLANDS...RANGING INTO THE  
LOWER 60S HIGHER ELEVATIONS. WENT CLOSER TO THE NATIONAL BLEND OF  
MODELS FOR TEMPERATURES THROUGH THE PERIOD.  
 

 
   
SHORT TERM /SUNDAY THROUGH MONDAY/
 
 
A RATHER MESSY FORECAST STILL FOR SATURDAY NIGHT THROUGH SUNDAY.  
LOOKS LIKE WE MAY HAVE A DRY PERIOD SATURDAY NIGHT ACROSS THE  
WEST...BUT STILL HANGING ONTO CHANCE POPS. HAVE LIKELY POPS ACROSS  
THE MOUNTAINS. ENTIRE CWA SHOULD GET SOME RAIN ON SUNDAY...BUT  
TIMING IS RATHER DIFFICULT. NAM SHOWS SOME BREAKS DURING THE  
AFTERNOON...WITH THE MAIN SLUG IN THE MORNING...WHILE GFS AND ECMWF  
HAVE LESS DEFINITION. THIS ALL MAKES IT DIFFICULT TO HIGHLIGHT WHEN  
THESE DRIER PERIODS MAY BE ON SUNDAY...SO GENERALLY KEPT HIGH POPS  
THROUGHOUT THE DAY...GRADUALLY TAPERING OFF SUNDAY NIGHT INTO  
MONDAY. DESPITE THE SHOWERS AND CLOUDS AROUND IN THE MORNING...THE  
NAM STILL INDICATED SOME DECENT INSTABILITY SUNDAY. IN  
ADDITION...NAM BULK SHEAR HAS INCREASED IN RECENT RUNS -- NOW  
GENERALLY 40-50KTS SUNDAY AFTERNOON. THINK THE MORNING ACTIVITY  
SHOULD LIMIT INSTABILITY SOME...BUT STILL CANNOT RULE OUT SOME  
STRONGER THUNDERSTORMS WITH GUSTY WINDS AND POSSIBLY HAIL.  
ALONG  
PWATS LOOK TO BE THE HIGHEST SATURDAY NIGHT ACROSS THE WESTERN HALF  
OF THE CWA...MAXING OUT JUST OVER 1.5 IN. GENERALLY HAVE ABOUT 1  
INCH OF QPF SATURDAY NIGHT THROUGH SUNDAY NIGHT. BUT ANY AREAS THAT  
RECEIVE REPETITIVE DOWNPOURS COULD START EXPERIENCING MINOR WATER  
ISSUES. WILL KEEP MENTION IN HWO FOR NOW.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
 
 
MODELS STILL DIFFER ON WAVE CROSSING THE MIDDLE ATLANTIC STATES  
TUESDAY INTO WEDNESDAY...BUT THERE IS INCREASING CONSENSUS ITS  
MOISTURE AFFECTS AT LEAST SOUTHEASTERN PORTIONS OF THE FORECAST  
AREA.  
 
MODELS ALSO REMAIN A BIT OUT OF SYNC WITH A COUPLE OF NORTHERN  
STREAM SYSTEMS THAT CROSS MID TO LATE WEEK. THE GFS BRINGS COLD  
FRONTS ACROSS LATE WEDNESDAY AND THEN FRIDAY NIGHT...WHILE THE  
ECMWF TIMING IS EARLY THURSDAY ON THE FIRST COLD FRONT...AND THEN  
IT JUST CLOSES OFF A LARGE UPPER LOW THAT THEN SLOWLY LUMBERS  
THROUGH THE AREA AT LEAST THE END OF THE PERIOD. THE GFS IS  
FARTHER NORTH AND DEEPER WITH THE UPPER LOW...HENCE THE MORE  
DEFINED SECOND SURFACE FRONT. AS FOR THE UPPER LOWS...THIS IS A  
CLASSIC CASE OF DEEPER...BY ABOUT 350M...AND FARTHER NORTH VERSUS  
WEAKER AND FARTHER SOUTH.  
 
THE CURRENT FORECAST BRINGS FRONTS AND THE ASSOCIATED CHANCE FOR  
SHOWERS ACROSS WEDNESDAY AND FRIDAY NIGHTS...SIMILAR TO THE WPC  
DEPICTION.  
 
KEPT LOWS CLOSE TO PREVIOUS FORECAST AND A GUIDANCE BLEND. BLENDED  
IN GFS-BASED GUIDANCE FOR HIGHS...A LITTLE LOWER THAN PREVIOUS  
FORECAST FOR THE MOST PART.  
 

 
   
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
 
 
OVERNIGHT...VFR CONDITIONS WILL PREVAIL...EXCEPT AT EKN...PKB...AND  
CKB THAT COULD SEE SOME MVFR/IFR FOG DURING THE PREDAWN HOURS.  
SATELLITE IMAGES SHOW HIGH CLOUDS CREEPING IN FROM THE SOUTH AND  
WEST...SHOULD GENERALLY PREVENT DENSE FOG DEVELOPMENT OVERNIGHT.  
 
A WARM FRONT LIFTS NORTH ON SATURDAY...WITH SCATTERED SHOWERS AND  
ISOLATED STORMS DURING THE EARLY AFTERNOON. WIDESPREAD MVFR  
CONDITIONS DEVELOPING AFTER 15-18Z...PARTICULARLY ACROSS THE  
EASTERN SLOPES OF THE HIGHER TERRAIN AND AT SITES SUCH AS KBKW AS  
A SOUTHEASTERLY FLOW TAKES HOLD. WV LOWLANDS MAY BE SLOWER TO  
DEVELOP MVFR CONDITIONS IN THE SOUTHEASTERLY DOWNSLOPING FLOW.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...  
 
FORECAST CONFIDENCE: MEDIUM.  
 
ALTERNATE SCENARIOS: CLOUD COVER COULD PREVENT FOG DEVELOPMENT  
TONIGHT. TIMING...COVERAGE AND DURATION OF ANY FOG OVERNIGHT  
TONIGHT COULD VARY. TIMING AND DEVELOPMENT OF MVFR CONDITIONS ON  
SATURDAY COULD 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.  
 
DATE SAT 04/30/16  
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17  
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13  
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 M M M  
BKW CONSISTENCY H H H H H H H H H M M M  
EKN CONSISTENCY L L L L L L L H H H H H  
PKB CONSISTENCY L L L L L L L M H H H H  
CKB CONSISTENCY L L L L L L L H H H H H  
 
AFTER 06Z SUNDAY...  
IFR POSSIBLE AGAIN SATURDAY NIGHT INTO SUNDAY NIGHT WITH ADDITIONAL  
ROUNDS OF SHOWERS AND THUNDERSTORMS..AND IN STRATUS LINGERING INTO  
MONDAY MORNING.  
 

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

 
 

 
SYNOPSIS...KTB/TRM/MZ  
NEAR TERM...ARJ  
SHORT TERM...MZ  
LONG TERM...TRM  
AVIATION...ARJ  
 
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