528  
FXUS61 KRLX 012102  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
502 PM EDT WED APR 1 2015  
   
SYNOPSIS
 
 
HIGH PRESSURE HEADS EAST TONIGHT. WARM FRONT THURSDAY. WAVE ALONG  
STRONG FRONTAL ZONE FRIDAY. IN ITS WAKE...COLD FRONT SWEEPS THROUGH  
FRIDAY EVENING. COOLER SATURDAY...WITH HIGH PRESSURE BUILDING IN.  
 

 
   
NEAR TERM /THROUGH THURSDAY/
 
 
LOTS OF SUNSHINE TODAY...WITH NARY A CLOUD ON VISIBLE SATELLITE  
ACROSS THE CWA. THIS IS THANKS TO A HIGH PRESSURE SYSTEM CURRENTLY  
OVER NORTHERN WEST VIRGINIA. THIS HIGH WILL PASS TO THE EAST  
TONIGHT...WITH SOUTHERLY WINDS BEGINNING TO INCREASE ON THE BACK  
SIDE BY MORNING. WITH THE HIGH OVERHEAD THIS AFTERNOON...LIGHT  
AND VARIABLE WINDS ARE IN PLACE. VERY DRY AIR IN THE LOWER  
ATMOSPHERE IS YIELDING RH VALUES IN THE 20S AND LOW 30S EAST OF  
THE OHIO RIVER...AND IN THE LOW TO MID 30S IN SOUTHEAST  
OHIO...CREATING SOME FIRE WEATHER CONCERNS.  
 
SURFACE LOW WILL MOVE INTO THE WESTERN GREAT LAKES TONIGHT...AND  
DRIVE A WARM FRONT ACROSS THE FORECAST AREA ON THURSDAY. BEST  
CHANCE OF PRECIP WITH THIS WILL BE IN SE OHIO...BUT HAVE ISOLATED  
TO SCATTERED SHOWERS/STORMS ACROSS MOST OF THE CWA AT SOME POINT  
THURSDAY AFTERNOON. THE CHANCE OF THICKER CLOUDS DOES CREATE THE  
POTENTIAL FOR A BUST ON THURSDAY HIGH TEMPS. PREVIOUS FORECAST IS  
HIGHER THAN ALL NEW GUIDANCE...IN FACT THE MAV WENT FROM LOW 80S  
FOR CRW A COUPLE RUNS AGO TO UPPER 60S WITH THE RECENT 12Z RUN.  
BIAS CORRECTED GUIDANCE IS RUNNING QUITE A BIT HIGHER THAN THE RAW  
OUTPUT. WITH ALL THAT SAID...OPTED TO BLEND IN SOME OF THE WARM  
BIAS CORRECTED NUMBERS...ENDING UP 2 OR 3 DEGREES COOLER THAN THE  
PREVIOUS FORECAST...AND QUITE A BIT WARMER THAN MOS.  
 

 
   
SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/
 
 
TWO DISTINCT AREAS OF STRONG DIVERGENCE ALOFT AT 250 MBS...ONE  
OVERNIGHT THURSDAY NIGHT MOVING THROUGH SRN INDIANA INTO OHIO BY 06Z  
FRIDAY. ANOTHER WAS ASSOCIATED WITH THE SURFACE WAVE ALONG THE  
FRONTAL BOUNDARY DURING THE DAY ON FRIDAY. 12Z GFS FURTHER SOUTH ON  
THAT SUPPORT FRIDAY...COMPARED TO THE 12Z NAM.  
 
PRECIPITABLE WATER INCREASES TO AROUND 1.3 INCHES BY 06Z FRIDAY AND  
REMAINS UNTIL FRONTAL PASSAGE. BASING FORECAST ON FRONT PASSING  
PKB-HTS AROUND 00Z SATURDAY...THEN QUICKLY REACHING EKN-BKW BY  
03Z/04Z SATURDAY.  
 
WITH SUPPORT ALOFT...HAVE ONE HEAVIER BATCH OF SHOWERS/EMBEDDED  
THUNDERSTORMS FIGURED FOR OVERNIGHT THURSDAY NIGHT IN OUR OHIO  
VALLEY COUNTIES INCLUDING SE OH AND NE KY. I LOT OF LEFTOVERS  
SHOULD LINGER FRIDAY MORNING. SECOND BATCH OF HEAVIER SHOWERS AND  
EMBEDDED THUNDERSTORMS FRIDAY AFTERNOON INTO EARLY EVENING.  
CURRENTLY HAVE ITS HEAVIEST RAIN AXIS FROM NORTH CENTRAL WV SW TO  
HTS VCNTY.  
 
WITH LOW LEVEL FLOW AT 40 TO 50 KNOTS ON FRIDAY....DESPITE MINIMUM  
INSTABILITY AND THE LEFTOVER CONVECTION FRIDAY MORNING...STILL  
CONCERNED SOME OF THAT WIND MAY MIX DOWN IN THE SHOWERS FRIDAY  
AFTERNOON OR EARLY EVENING. WOULD NOT NEED T. THE GUSTY WIND THREAT  
MAY BE A BIT FURTHER SOUTH THAN THE MAXIMUM RAINFALL AXIS.  
 
WILL ADD THE 2 CONCERNS TO OUR HAZARDOUS WEATHER POTENTIAL IN .  
STILL THINKING ABOUT 2 INCHES OF RAIN STORM TOTAL WOULD BE NEEDED  
FOR HIGH WATER CONCERNS. IF THE ROUNDS FRIDAY AFTERNOON AFFECT THE  
SAME AREAS AS OVERNIGHT THURSDAY NIGHT...WE COULD NOT COMPLETELY  
RULE THAT OUT. ALSO...SOME DAMAGING WIND GUSTS MAY DEVELOP FRIDAY  
AFTERNOON IN THE SHOWERS AS THE WAVE ORGANIZES.  
 
IN THE WAKE OF THE FRONT...HELD ONTO HIGHER POPS A BIT LONGER IN THE  
WESTERN LOWLANDS DURING FRIDAY NIGHT. WE STILL HAVE ON EITHER SIDE  
OF AN INCH OF SNOW ACCUM AOB 3500 FEET IN THE WV MOUNTAINS FOR 06Z  
TO 12Z SATURDAY. CLEARING DEVELOPS SATURDAY...WITH HIGH PRESSURE  
BUILDING IN.  
 
NO BIG CHANGES TO OUR MAXIMUM AND MINIMUM TEMPERATURES. OF COURSE...  
TEMPERATURES WILL REMAIN MILD THURSDAY NIGHT IN THE WARM SECTOR.  
FRIDAY MAXIMUM TEMPERATURE HIGHLY DEPENDENT ON THE TIMING OF  
SPECIFIC ROUNDS OF SHOWERS.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
 
 
HIGH PRESSURE PROVIDES A DRY CLOSE TO THIS UPCOMING EASTER WEEKEND.  
A FRONT APPROACHES FROM THE N AND GETS CLOSE TO THE NRN EDGE OF THE  
CWA SUN NT...BEFORE RETREATING N ON MON. THIS CONTINUES THE DRY  
WEATHER.  
 
MODELS CONCUR ON A LOW PRESSURE SYSTEM AND COLD FRONT APPROACHING  
FROM THE W MON NT AND TUE. AFTER THAT...THOUGH...MODEL TIMING  
DIFFERENCES SHOW UP. THE ECMWF CONTINUES TO PRESENT THE SLOWER  
SOLN...WITH THE LOW CENTER DEGENERATING INTO SEVERAL WEAKER FLAT  
WAVES PASSING JUST N OF THE CWA THROUGH THE BALANCE OF THE PERIOD.  
IT HAS A NEW LOW PRESSURE CENTER JUST REACHING THE LOWER OHIO VALLEY  
AT THE END OF THE PERIOD...12Z THU DAY 8...WHICH THEN CROSSES THE  
CWA DAY 9.  
 
THE FASTER GFS HAS THE ORIGINAL LOW CENTER PLUGGING RIGHT  
ALONG...PASSING N OF THE AREA TUE NT...AND DRAGGING ITS COLD FRONT  
ACROSS THE AREA OVERNIGHT INTO WED MORNING. THE WPC MAPS FOLLOW THE  
ECMWF BUT THEIR POPS AND OTHER ELEMENTS REFLECT MORE OF A BLEND...AS  
DOES THIS FCST.  
 
THIS ALL HINGES ON HOW MUCH ENERGY FROM WRN CONUS TROUGHINESS SCOOTS  
E. THE GFS QUICKLY SCOOTS A PIECE OF IT E...ALLOWING RIDGING AND  
SFC HIGH PRESSURE TO BUILD IN ITS WAKE DAY 7. THE ECMWF TRIES TO  
BRING THE BULK OF THE TROUGH EWD...BUT MUCH MORE SLOWLY...KEEPING  
THE WEATHER UNSETTLED PRETTY MUCH THE BALANCE OF THE PERIOD...IF NOT  
THE BALANCE OF THE WORK WEEK.  
 
BLENDED IN WPC AND BIAS CORRECTED MOS GUIDANCE FOR LOWS THROUGH THE  
PERIOD AND FOR HIGHS MON. HAVE LOWS A LITTLE LOWER THAN PREVIOUS  
UNDER HIGH PRESSURE SAT NT...AND HIGHS A BIT HIGHER FOR EASTER  
SUNDAY. LITTLE TEMPERATURE CHANGES MADE BEYOND MON WITH PREVIOUS  
FCST ACCEPTED FOR HIGHS TUE-WED.  
 

 
   
AVIATION /21Z WEDNESDAY THROUGH MONDAY/
 
 
VFR EXPECTED THROUGH THE PERIOD...ALTHOUGH AM EXPECTING SOME  
SHOWERS/STORMS THURSDAY. BEST CHANCE WILL BE ACROSS SE OHIO...AND  
COULD GET MVFR IN ANY STRONGER SHOWERS OR STORMS. DID MENTION VCTS  
AT HTS AND PKB. VARIABLE WINDS TODAY WILL BECOME MORE SOUTHERLY  
TONIGHT INTO TOMORROW...WITH SOME GUSTS AROUND 20 KTS DURING THE  
AFTERNOON.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...  
 
FORECAST CONFIDENCE: HIGH.  
 
ALTERNATE SCENARIOS: MAY GET BRIEF FLIGHT CATEGORY RESTRICTIONS IN  
SHOWERS/STORMS THURSDAY AFTERNOON.  
 
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 20 21 22 23 00 01 02 03 04 05 06 07  
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03  
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...  
IFR POSSIBLE IN SHOWERS AND/OR STORMS THURSDAY NIGHT THROUGH  
FRIDAY NIGHT.  
 

 
   
FIRE WEATHER
 
 
FUEL MOISTURE GENERALLY RUNNING UNDER 10 PERCENT ACCORDING TO RAWS  
ACROSS THE FORECAST AREA. THIS COMBINED WITH RH VALUES DROPPING  
INTO THE 20S THIS AFTERNOON WILL CONTINUE TO PROVIDE ENHANCED  
RISK OF FIRE SPREAD. FORTUNATELY...WINDS ARE FAIRLY  
LIGHT...GENERALLY UNDER 10 MPH.  
 
WINDS WILL PICK UP LATE TONIGHT OUT OF THE SOUTH AS A HIGH  
PRESSURE PASSES TO OUR EAST. EXPECTING SOUTHERLY WINDS OF 5-15 MPH  
GUSTING TO 20-25 MPH. DEWPOINTS WILL INCREASE AS A WARM FRONT  
PASSES...BUT A VERY WARM AFTERNOON WILL STILL YIELD RELATIVE  
HUMIDITY LEVELS DROPPING INTO THE 30S TO LOW 40S. ISOLATED TO  
SCATTERED SHOWERS OR STORMS ARE POSSIBLE WITH THE WARM FRONT.  
 
A COLD FRONT WILL BRING WETTING RAIN FRIDAY INTO FRIDAY NIGHT.  
 

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

 
 

 
SYNOPSIS...KTB/TRM/MZ  
NEAR TERM...MZ  
SHORT TERM...KTB  
LONG TERM...TRM  
AVIATION...MZ  
 
FIRE WEATHER...MZ  
 
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