Area Forecast Discussion
Issued by NWS Charleston, WV

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRLX 181937 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 337 PM EDT MON AUG 18 2014 .SYNOPSIS... SFC LOW PRESSURE MOVES EAST ACROSS EASTERN MOUNTAINS THIS EVENING. MUGGY AIR REMAINS IN PLACE...WITH SHOWERS AND FOG OVERNIGHT. A VERY HUMID AND ACTIVE PATTERN NEARLY EVERYDAY THROUGHOUT THE WEEK. && .NEAR TERM /THROUGH TUESDAY/... RADAR AND SATELLITE IMAGES SHOW CENTER OF SURFACE LOW JUST WEST OF CRW AT 18Z. THE BULK OF PCPN IS NOTICED ACROSS THE NORTHEAST THROUGH SOUTH OF THE LOW...BUT HAS DIMINISHED IN INTENSITY DURING THE LAST FEW HOURS. THIS LOW WILL EXIT THE EASTERN MOUNTAINS LATER TONIGHT LEAVING ONLY RESIDUAL LIGHT RAIN SHOWERS AND MOGGY AIR MASS. DEWPOINTS UPSTREAMS ARE IN THE UPPER 60S TO LOWER 70S. THESE DEWPOINTS WILL ADVECT INTO OUR AREA TONIGHT...A DETERMINANT FACTOR FOR LOWS TEMPERATURES TONIGHT. DECREASED POPS ACROSS THE NORTH AND EAST OF THE AREA AS WATER VAPOR IMAGES SHOW A LARGE AREA OF DRIER AIR MOVING OUR WAY. HOWEVER...ON TUESDAY...WITH THE DIURNAL HEATING AND ABUNDANT LOW LEVEL MOISTURE...SHOWERS AND THUNDERSTORMS ARE POSSIBLE. BUFKIT SOUNDING SHOW FAT CAPE FEATURE ACROSS THE LOWLANDS ON TUESDAY. A GRADUAL WARMING IS EXPECTED THROUGH TUESDAY. WENT WITH A BLEND OF BIAS CORRECTED SREF AND CONSENSUS MOS THROUGH THE PERIOD. ANOTHER SYSTEM MOVES IN LATE TUESDAY INTO TUESDAY NIGHT. INCREASED POPS GRADUALLY TO CHANCE POPS FOR NOW. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
CONTINUED ACTIVE IN THE SHORT TERM PERIOD...WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. GENERALLY SPEAKING...THE HIGHEST CHANCES FOR PRECIP OCCUR TUE EVENING AND THEN AGAIN THURSDAY...WITH A LESSER CHANCE OF PRECIP WED. OVERALL...NO MAJOR WHOLESALE CHANGES TO ONGOING FORECAST. TUESDAY EVENING A FAST-MOVING S/W TROUGH PROGGED TO BE LOCATED OVER INDIANA AND MOVING E/SE WARD. THE SFC FRONT STILL PROGGED TO BE LAGGING BEHIND...BUT IT APPEARS THAT A PREFRONTAL BAND WILL MOVE ACROSS THE AREA TUE EVE OUT AHEAD OF FRONT WITH S/W TROUGH. SOME INDICATION THAT THIS CONVECTIVE LINE WILL ARRIVE LATER THAN 00Z WED...PERHAPS MORE LIKE 03Z WED. KEPT INHERITED LIKELY POPS OVER THE SE OHIO ZONES HOWEVER AS THESE PROGRESSIVE SYSTEMS SEEM TO HAVE A WAY OF PROPAGATING MUCH QUICKER THAN THE SYNOPTIC SCALE FORCING WOULD INDICATE. MARGINAL SHEAR AROUND 25KTS AND ML CAPE VALS OF 1000-1500J/KG INDICATE THE POTENTIAL FOR STRONG STORMS...WITH A STORM OR TWO POSSIBLY REACHING SVR LIMITS...MAINLY OVER THE SE OHIO ZONES. STRONG WINDS WOULD BE THE PRIMARY HAZARD...BUT LARGE HAIL CAN/T BE COMPLETELY RULED OUT. THESE SHOWERS AND STORMS WILL LIKELY CONTINUE ACROSS THE AREA DURING THE EVENING AND INTO THE OVERNIGHT HOURS WITH SOME SFC INSTABILITY REMAINING EVEN DURING THE OVERNIGHT PERIOD...BUT THEY WILL BE WEAKENING AS THEY DO SO. BY WED...S/W TROUGH IS EXITING THE EASTERN MOUNTAINS AROUND 12Z WITH MAIN GENERAL AREA OF PRECIP EXITING WITH IT. SOMEWHAT DRIER AIR PUSHES IN AS WELL ON A W/NW FLOW ALOFT. SFC FRONT TO THE WEST CONTINUES TO MOVE EASTWARD BUT BECOMES MORE DIFFUSE ON ITS SOUTHERN END. WITH SOME LLVL MOISTURE REMAINING WITH PWATS UP AROUND THE 1.40IN-1.60IN RANGE HAVE CONTINUED LOW/MID CHANCE POPS BY WED AFTERNOON...WITH THE BETTER CHANCE FOR SHOWERS/STORMS BEING ACROSS THE FAR NORTHERN ZONES AS THE FRONT BRUSHES THAT AREA. SHOULD BE ANOTHER LULL IN OVERNIGHT PRECIP WED NIGHT BUT PRECIP CHANCES INCREASE FROM SW TO NE DURING THE DAY ON THURSDAY AS A WARM FRONT MOVES NORTHEAST...COINCIDENT WITH ANOTHER S/W TROUGH MOVING OVERHEAD DURING THE AFTERNOON HOURS IN THE FLOW ALOFT.
-- End Changed Discussion --
&& .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
SIDED GENERALLY WITH WPC THINKING FOR THE LONG-TERM PERIOD WITH A FEW TWEAKS BASED ON ENSEMBLE GUIDANCE. GENERAL PATTERN WILL BE CHARACTERIZED BY NORTHWEST FLOW ALOFT WITH PERSISTENT UPPER HIGH PARKED OVER THE SOUTHERN MISS VALLEY REGION AND LONGWAVE TROUGH OFF THE NORTHEAST COAST. HOWEVER...NAILING DOWN THE DETAILS AT THIS DISTANCE IN TIME IS DIFFICULT. AS SUCH...CONTINUE AT LEAST SLIGHT CHANCE POPS THROUGH THE ENTIRE PERIOD WITH THE HIGHEST CHANCE COMING THURSDAY NIGHT INTO FRIDAY MORNING AS A WARM FRONT LIFTS NORTHEAST. TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO REMAIN FAIRLY SEASONAL...WITH NO REAL HEATWAVES OR COOL PERIODS.
-- End Changed Discussion --
&& .AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
PERIODS OF IFR FOG UNDER LIGHT RAIN WILL CONTINUE ACROSS CRW...BKW AND VICINITY AREAS FOR AT LEAST 22Z. RADAR IMAGES SHOW THE SURFACE LOW PRESSURE SPINNING OVERHEAD WITH PCPN TO THE EAST THROUGH SOUTH. THIS LOW WILL SLOWLY MOVE EAST...EXPECTED OVER THE EASTERN MOUNTAINS LATER THIS EVENING TAKING MOST OF THE PCPN AWAY FROM THE AREA. OVERNIGHT...LAV GUIDANCE AND BUFKIT SOUNDINGS SUGGEST IFR CONDITIONS POSSIBLE ACROSS THE SOUTHERN SITES...INCLUDING CRW...BKW...AND HTS. ONLY SITES ACROSS THE SOUTH RECORDED PCPN TODAY. WITH BOUNDARY LAYER WINDS ABOUT 5 KNOTS AND PLENTY OF LOW LEVEL MOISTURE AVAILABLE AS SEEN ON DEWPOINTS IN THE UPPER 60S...IFR CONDITIONS SOUNDS REASONABLE AT MOST PLACES TONIGHT. IT WILL BE POST RAINFALL FOG...INSTEAD OF RADIATIONAL FOG. MODELS SUGGEST PLENTY OF CLOUD COVER IN LOW STRATUS MAINLY OVER THE EASTERN MOUNTAINS INCLUDING EKN. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING OF DEVELOPMENT OF SHOWERS AND ASSOCIATED MVFR/IFR CONDITIONS MAY VARY FROM FORECAST. MVFR/IFR CIGS AFTER 00Z MAY DEPEND ON SKY COVER. 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 L L H HTS CONSISTENCY H M M H H H H H H H L L BKW CONSISTENCY H H M H H H M H H M M H EKN CONSISTENCY H H H H H H M M H H L H PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H M M H L L H AFTER 18Z TUESDAY... IFR POSSIBLE IN POST RAIN STRATUS AND FOG INTO WEDNESDAY MORNING AND SUBSEQUENT MORNINGS...AND IN SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING.
-- End Changed Discussion --
&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR WVZ005-006- 013>015-024>027-033>038. OH...NONE. KY...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR KYZ102-103- 105. VA...FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR VAZ003-004. && $$ SYNOPSIS...ARJ/50 NEAR TERM...ARJ SHORT TERM...50 LONG TERM...50 AVIATION...ARJ

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