Area Forecast Discussion
Issued by NWS Charleston, WV

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRLX 021028 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 628 AM EDT THU OCT 2 2014 .SYNOPSIS... WARM SUMMER LIKE AFTERNOON TODAY. STRONG COLD FRONT STREAKS ACROSS FRIDAY EVENING. MUCH COLDER AIR ARRIVES FOR THE WEEKEND. REINFORCING COLD FRONT MAY ARRIVE EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE HUM OF A/C(S) THIS AFTERNOON IN THE NEAR TERM...REPLACED IN THE SHORT TERM BY HOME FURNACES FIRING UP SATURDAY OR SATURDAY NIGHT. DIURNAL FOG COMMON ALONG THE RIVER VALLEYS IN WV AND SW VA THIS PREDAWN. DRIER IN SE OHIO...BUT COOLER...SO SOME PATCHY FOG STILL LIKELY THERE FOR THE PREDAWN HOURS. WINDS AT 925 TO 850 MBS NOT INCREASING ALL THAT FAST TODAY...STILL ONLY AROUND 10 KNOTS FOR 18Z TODAY THROUGH 00Z FRIDAY. CERTAINLY THE LAST OF THE WEAK WIND FLOW. THE ATMOSPHERE ABOUT TO GET ENERGIZED. THE FIRST INDICATIONS ARE INCREASING LOW LEVEL WINDS 06Z TO 12Z FRIDAY. WITH THE WEAK WINDS TODAY...WAS A BIT HESITANT TO JUMP ON THE WARMER MOS MAX TEMPERATURE GUIDANCE. WILL LIKELY STAY WITH OUR PREVIOUS FORECAST OF MOSTLY 80 TO 85 RATHER THAN THE MID 80S FOR THE USUAL HOT SPOTS. A WEAK 500 MB VORT MAX COMES ACROSS OHIO TODAY INTO THE RIDGE...SO A BIT MORE CLOUDS FOR NRN PORTIONS OF SE OHIO. THINK SOME OF THE MOUNTAIN VALLEY...SUCH AS THE TYGART VALLEY AND UPPER GREENBRIER VALLEY...WILL DECOUPLE THIS EVENING...BEFORE WINDS INCREASE ABOVE THEIR SHALLOW SURFACE INVERSION. SO THE ONLY FOG MENTIONED LATE TONIGHT WILL BE THERE. FURTHER WEST...THINKING WINDS WILL STIR DURING THE LATE NIGHT HOURS...WITH MILDER TEMPERATURES. NO BIG CHANCES ON OUR POPS...WHICH HAVE BE FAIRLY CONSISTENT THE PAST SEVERAL DAYS ON FRIDAY`S POPS. STILL HAVE 30 TO 40 POPS ARRIVING TOWARD 10Z FRIDAY ALONG OUR WESTERN BORDER COUNTIES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... FAIRLY COMPLEX FORECAST WITH LOTS OF MOVING PIECES FOR THE SHORT TERM. HAVE A STRONG COLD FRONT PUSHING THROUGH...FOLLOWED BY AN UPPER AIR TROUGH...RESULTING IN A DRASTIC COOL DOWN BY THE END OF THE PERIOD. HAVE COLD FRONT SET TO CROSS CWA FRIDAY AFTERNOON AND EVENING... ENTERING FROM THE WEST AROUND 20Z AND EXITING EAST AROUND 05Z SAT. THIS IS FAIRLY CLOSE TO A GFS/ECMWF BLEND...AND A BIT FASTER THAN THE NAM. SO HAVE AN AREA OF 80-90 POPS CROSSING THE CWA FROM WEST TO EAST FRIDAY AFTERNOON AND EVENING...AND REALLY MAKE ONLY LITTLE CHANGES TO TIMING WHEN COMPARED TO PREVIOUS FORECAST. OF NOTE...00Z ECMWF AND GFS SPLIT MAX QPF AND TAKE IT NORTH AND SOUTH OF CWA...BUT STILL ANTICIPATE ENOUGH SHOWERS AND THUNDERSTORMS MOVING THROUGH TO BE COMFORTABLE WITH HIGH POPS...ALTHOUGH QPF FORECAST MAY BE A TOUCH HIGH. INSTABILITY REMAINS FAIRLY LIMITED AHEAD OF THE COLD FRONT...WITH CAPE UP TO ABOUT 500-800 J/KG. BUT THE CAPE PROFILES ARE VERY SKINNY AND WOULD NOT SUPPORT VIGOROUS UPDRAFTS BY THEMSELVES WHICH SHOULD LIMIT ORGANIZED...WIDESPREAD STRONG TO SEVERE THREAT. WITH THAT SAID...VERY RESPECTABLE BULK SHEAR -- 40-50KTS -- COMBINED WITH GOOD DYNAMICS AND FAST FLOW SHOULD ALLOW FOR ATLEAST SOME ENHANCED OUTFLOW WINDS. WILL CONTINUE GUSTY OUTFLOW MENTION IN HWO FOR THIS. WHILE SIDING MOSTLY WITH THE ECMWF AND GFS ON TIMING...DID NOT DISCOUNT THE NAM COMPLETELY...AND THINK THE HIGHER RESOLUTION IS PICKING UP ON SECONDARY -- POST FRONTAL PRECIP BAND ASSOCIATED WITH UPPER LEVEL VORT MAX AND COLD AIR. WITHOUT GOING ALL IN...DID INCLUDE A POP MINIMUM JUST BEHIND THE FRONT...WITH ANOTHER AREA OF LIKELY POPS QUICKLY MOVING THROUGH DURING THE LATE EVENING AND EARLY OVERNIGHT...AS THE COLD AIR ENTERING ALOFT SQUEEZES OUT REMAINING UPPER AND MID LEVEL MOISTURE. UPPER LEVEL TROUGH CROSSES SATURDAY...SO INCREASED CLOUDS CONSIDERABLY. DESPITE WHOLE COLUMN DRYING OUT...LOW LEVEL MOISTURE REMAINS AND FORECAST SOUNDING SHOW GOOD SATURATED LAYER BELOW 10KFT...LINGERING ACROSS WV LOWLANDS FOR MUCH OF THE DAY. COULD EVEN GET DRIZZLE OR A LIGHT SHOWER OUT OF THIS BUT DID NOT INCLUDE LOW END POPS AT THIS POINT. DID NOT CHANGE HIGHS AND LOWS ALL THAT MUCH...ALTHOUGH DID COOL THE MOUNTAINS SATURDAY AND WENT WITH A NON-DIURNAL AT THE HIGHEST ELEVATIONS AS COLD 850 AIR FILTERS IN. THIS HAPPENS JUST AS THE LAST OF THE LOW LEVEL MOISTURE IS BEING SQUEEZED OUT...AND INCLUDED SOME SNOW FLAKES ABOVE 4000 FEET LATE SATURDAY. HAVE TEMPS DIPPING INTO THE UPPER 20S SATURDAY NIGHT IN THE NORTHERN MOUNTAINS...SO WILL INCLUDE POTENTIAL FREEZE IN HWO. HELD OFF ON MENTION OF FROST WHERE TEMPS ARE IN THE LOW TO MID 30S...EXPECTING WINDS TO KEEP UP ENOUGH TO LIMIT ANY DECOUPLING AND FROST FORMATION. WILL NEED TO BE RE-EVALUATED AS WE GET CLOSER. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... BAROCLINIC ZONE SHIFTS SLOWLY NWD THIS PERIOD AS THE SWD EXTENT OF THE L/W SLOWLY RETREATS. THIS RESULTS IN GRADUALLY MODERATING TEMPERATURES. MODELS DISAGREE ON TIMING AND EXTENT OF REINFORCING COLD FRONT EARLY NEXT WEEK. FOLLOWED WPC IDEA OF CHANCE POPS MON INTO TUE...WITH NO APPRECIABLE COOL DOWN THEREAFTER. BLENDED IN WPC TEMPERATURES FOR MOST OF THE FCST. && .AVIATION /10Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
LAST EARLY MORNING FOR WIDESPREAD VALLEY FOG...BURNING OFF 12Z TO 13Z. VFR WITH JUST A FEW TO SCATTERED CU AT 4 TO 6 THSD FT AGL THIS AFTERNOON WITH THIN HIGH CIRRUS ABOVE. SOME PATCHES OF MID DECK AOA 10 THSD FT MAY ARRIVE 00Z TO 06Z FRIDAY IN THE WESTERN LOWLANDS. LOW LEVEL FLOW FROM THE SE-S INCREASING 06Z TO 12Z FRIDAY. ONLY FOG FIGURED FOR 06Z TO 12Z FRIDAY IS IN THE DEEP MOUNTAIN VALLEYS NEAR ELKINS. CLOUDS AT 5 TO 10 THSD FT THICKENING FROM SW 06Z TO 12Z FOR THE OHIO RIVER VALLEY COUNTIES. LEADING LIGHT SHOWERS MAY BE NEARING NE KY AND SE OHIO BY 12Z FRIDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: LEFTOVER STRATUS OVER RIVERS MAY LINGER A HOUR OR SO LONGER THAN 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. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY L L L L H H H H H H H H HTS CONSISTENCY L L M L H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY L L L M H H H H H H H H PKB CONSISTENCY L L M H H H H H H H H H CKB CONSISTENCY L L M L L H H H H H H H AFTER 12Z FRIDAY... BRIEF IFR IN FAST MOVING SHOWERS AND/OR THUNDERSTORMS FRIDAY AFTERNOON INTO FRIDAY NIGHT. POST FRONTAL IFR OVERNIGHT FRIDAY NIGHT...LINGERING IN MOUNTAINS EARLY SATURDAY...IN RAIN AND LOW CLOUDS IN THE COLD AIR ADVECTION
-- End Changed Discussion --
&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/MZ NEAR TERM...KTB SHORT TERM...MZ LONG TERM...TRM AVIATION...KTB

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.