655 FXUS61 KRLX 231742 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 142 PM EDT MON APR 23 2012 .SYNOPSIS... DEVELOPING LOW PRESSURE SYSTEM MOVES NORTH ALONG THE MID ATLANTIC COAST THROUGH TODAY. UPPER LEVEL LOW MOVES SOUTHEAST THIS MORNING. A CLIPPER LIKE SYSTEM WILL AFFECT THE AREA BY MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... LOWERED POPS AND SPEEDING UP CLEARING ACROSS THE WESTERN HALF OF THE FORECAST AREA. WILL ALSO INCREASE MAX TEMPS IN THE WEST FOR TODAY. IN EFFECT...THIS INCREASES THE WEST TO EAST GRADIENT IN MAX TEMPERATURE GRIDS AS COLD WINTRY SYSTEM SLOWLY EXITS OUR NORTHEAST MOUNTAINS. SOME WRAP AROUND MOISTURE STILL ENTERING RANDOLPH AND POCAHONTAS COUNTY...BRINGING A ROUND OF LIGHT TO MODERATE SNOW ACROSS THE HIGHER ELEVATIONS. ADDITIONAL ACCUMULATIONS WILL OCCUR ONLY AT THE HIGHEST TERRAIN WHILE LOWER ELEVATIONS AND VALLEY FLOORS HAVE BEEN SPARED THE HEAVIEST SNOW. WILL KEEP HEADLINES IN PLACE FOR NOW AS PRECIP IS STILL ONGOING. SAT IR ENHANCEMENT OVER WESTERN PA AND NORTHEAST WV STARTING TO DWINDLE AND SOME ADJUSTMENTS TO HEADLINES WILL OCCUR ONCE PRECIP PRODUCTION HAS SUFFICIENTLY DIMINISHED. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... GENERALLY WENT WITH GFS/SREF/ECMWF MODEL BLEND THROUGH THIS PERIOD...WITH NAM BEING THE OUTLIER. SFC LOW OVER NORTHERN GREAT LAKES WILL CONTINUE TO MOVE NORTHWARD AND ITS AFFECTS WILL DEPART WITH IT...BUT KEPT SOME LINGERING MOISTURE AND POPS IN THE NORTHERN MOUNTAIN ZONES DURING THE DAY ON TUESDAY...WITH GRADUAL DECREASE. A WEAK UPPER LEVEL SYSTEM SLIDES SOUTH OF THE CWA ON TUESDAY AS WELL...WITH MOST OF THE ENERGY STAYING SOUTH OF CWA. IN ANY CASE KEPT SLGHT CHC POPS ACROSS EXTREME SW AND SRN PORTION OF CWA ON TUESDAY AS WELL. BRIEF BREAK BEFORE MORE VIGOROUS SYSTEM MOVES DOWN FROM THE UPPER MIDWEST AND TRACKS ACROSS THE CWA WENDESDAY NIGHT AND THURSDAY. TEMPERATURES WILL GRADUALLY WARM TROUGH'S THE PERIOD AS SOUTHERLY FLOW WILL INCREASE ON TUESDAY AND WEDNESDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... UNSETTLED WEATHER EXPECTED IN THE LONG TERM. CLIPPER TYPE SYSTEM WILL MOVE THROUGH THE REGION ON THURSDAY...BRINGING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH THROUGH THE AREA LATE THURSDAY...BEFORE STALLING TO OUR SOUTH ON FRIDAY AS HIGH PRESSURE BRIEFLY BUILDS IN FROM THE NORTH...PROVIDING A BRIEF BREAK IN THE WEATHER. AS USUAL...QUITE A BIT OF UNCERTAINTY IN THE LATTER PART OF THE EXTENDED...BUT APPEARS AS THOUGH ANOTHER WAVE OF LOW PRESSURE WILL PUSH THROUGH THE AREA BY SUNDAY...BRINGING YET ANOTHER ROUND OF PRECIPITATION TO THE AREA. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... EASTERN HALF OF FORECAST AREA COVERED WITH IFR AND MVFR CONDITIONS AS STORM SYSTEM MOVES NORTH AND EAST AWAY FROM THE MIDLANTIC STATES. WESTERN SITES WILL PRIMARILY REMAIN UNDER VFR CONDITIONS. CIG AND VISBY VALUES GRADUALLY IMPROVES OVER THE EASTERN MOUNTAINS. HOWEVER...UPSLOPE SNOW SHOWERS WILL CONTINUE FOR A TIME...ESPECIALLY IN AND AROUND KEKN. EXPECT PRIMARILY VFR CONDITIONS FOR MONDAY. SFC PRESSURE GRADIENTS REMAIN IN PLACE AS LOW DEEPENS. THIS WILL LEAD TO PERSISTENT GUSTY NORTHWEST WINDS. BL SHOULD REMAIN FAIRLY MIXED FOR THE OVERNIGHT HOURS...ALLOWING SOME OVERNIGHT WINDS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: HEAVIER SNOW SHOWERS MAY CAUSE FURTHER REDUCTION IN CIG AND VSBY VALUES. TIMING PRECIP END AND IFR / LIFR IN SNOW MAY VARY. 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 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY M 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 L L M M M M M M M M M M EKN CONSISTENCY M M M L L L M L M M M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY M L L L M M L H H H H H AFTER 18Z TUESDAY... IFR CONDITIONS IN MOUNTAIN SNOW AND LINGERING LOW CLOUDS MON NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR WVZ037>040-046-047. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JS/ARJ NEAR TERM...KMC SHORT TERM...JS LONG TERM...SL AVIATION...KMC