531 FXUS61 KRLX 122341 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 641 PM EST SAT MAR 12 2016 .SYNOPSIS... A WARM FRONT SLOWLY LIFTS NORTHWARD THROUGH THE AREA TONIGHT THROUGH SUNDAY. AN UPPER LEVEL DISTURBANCE WILL KEEP THE CHANCE FOR SHOWERS GOING ON MONDAY. && .NEAR TERM /THROUGH SUNDAY/... 630 PM UPDATE... MUCH OF THE AREA IS VOID OF PRECIP ATTM...HOWEVER...THAT WILL CHANGE AS THE NIGHT PROGRESSES COURTESY OF AN APPROACHING WARM FRONT. TWEAKED POPS THIS EVENING TO START OFF DRY AND KEEP THE FOCUS OF HIGH POPS ACROSS SE OH AND N WV OVERNIGHT. INSTABILITY REMAINS WEAK AND ELEVATED SO THUNDER CHANCES REMAIN SMALL BUT NOT IMPOSSIBLE. PREVIOUS DISCUSSION BELOW... A WARM FRONT ACROSS SRN WV AND SERN KY EARLY THIS AFTERNOON WILL INCH SLOWLY THROUGH THE AREA THROUGH SUNDAY MORNING. LOW LEVEL MOISTURE FIELDS SUGGESTS AT LEAST TWO ROUNDS OF PRECIPITATION ASSOCIATED WITH THE FRONT...BUT THE FIRST ROUND...DESPITE THE WAVY APPEARANCE IN THE STLT IMAGERY...WAS HAVING TROUBLE GENERATING ENOUGH HYDROMETEORS TO MEASURE AT THE SFC. MORNING SOUNDINGS SUGGESTED SHARP DEEP LAYER MOISTURE GRADIENT ACROSS NRN PORTIONS OF THE FCST AREA...AND THE FIRST ROUND OF PRECIPITATION/VIRGA SHOULD MOISTEN THE ATMOSPHERE ENOUGH FOR THE SECOND ROUND TO BE MUCH MORE EFFECTIVE...AND SHOWERS LIKELY BECOMING WIDESPREAD OVERNIGHT TONIGHT AND CONTINUING INTO SUNDAY. EARLY MORNING WARM ADVECTION THUNDER ON ELEVATED INSTABILITY IS ALSO POSSIBLE. THE WARM FRONT SHOULD BE N OF AT LEAST MOST OF THE AREA SUNDAY AFTERNOON...LEAVING MOIST AND UNSTABLE AIR IN PLACE. THIS IS LIKELY TO CONTINUE OR RETURN SHOWERS AND THUNDERSTORMS TO THE AREA GIVEN A PARADE OF WAVES IN THE UPPER LEVEL SW FLOW. MID LEVEL FLOW AND CAPE ARE FCST TO BE MODEST...AND WITH LIMITED EARLY SEASON HEATING DEPENDING UPON BREAKS IN THE CLOUDS...THE THUNDERSTORMS ARE NOT LIKELY TO BECOME VERY STRONG. NEWER FCST DATA BETTER DEPICT THE TEMPERATURE AND DEW POINT GRADIENTS ACROSS THE AREA ASSOCIATED WITH THE WARM FRONT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... A COLD FRONT SINKS SOUTH ACROSS PA..OH AND WV...AT THE SAME TIME AN OLD BOUNDARY LIFTS NORTH AS A WARM FRONT ASSOCIATED WITH A DEVELOPING SFC LOW PRESSURE OVER THE MS VALLEY. ADJUSTED POPS ADDING FEW DETAILS. SO...FROM LIKELY POPS SUNDAY NIGHT...TO CATEGORICAL POPS MONDAY. SHOWERS OR STORMS ARE LIKELY SUNDAY NIGHT AS THE REMNANTS OF THE AFTERNOON CONVECTION DISSIPATE IN THE EVENING. NAM MODEL SUGGESTS PRECIPITABLE WATER ABOUT 1.32 INCHES. SFC CAPE VALUES WILL RISE AROUND 1000 J/KG. FOR MONDAY...SFC CAPE VALUES EXCEEDING 2000 J/KG WILL BE A CRUCIAL INGREDIENT FOR THUNDERSTORM INITIATION IN THE PRESENCE OF DEEP LAYERED SHEAR OF ABOUT 35 KNOTS. BY MONDAY NIGHT...THE BULK OF THE PCPN WILL MOVE OVER THE NORTHEAST MOUNTAINS...WITH POPS GRADUALLY DECREASING INTO DRIER CONDITIONS THROUGH TUESDAY. MODELS SHOWING SOME DRIER AIR MOVING OVER THE AREA ON TUESDAY...ALLOWING FOR DRY WEATHER FOR PART OF THE DAY. WENT CLOSER TO THE ALL BLEND AND THE SUPER BLEND FOR TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WE KICK OFF THE LONG TERM PERIOD IN A ZONAL PROGRESSIVE PATTERN AND ANY WEAK SYSTEM THAT COMES THROUGH WILL BRING NOTHING MORE THAN A FEW SHOWERS THROUGH THE END OF NEXT WEEK. BY NEXT WEEKEND THE OPERATIONAL AND ENSEMBLE GUIDANCE IS INDICATING A SWITCH TO MERIDIONAL FLOW...AS BRIEF RIDGING GIVES WAY TO A BROAD LONG WAVE TROUGH THAT DIGS OVER THE EASTERN CONUS. THIS WOULD GIVE US A SHOT OF COOLER AIR AND TEMPS WOULD TURN CLOSER TO AVERAGE VALUES. AS FAR AS THE SENSIBLE WEATHER GOES IT BECOMES TOUGH TO SORT OUT AT THIS TIME WITH THIS TROUGH ARRIVING CLOSE TO DAY 7 IN THE FORECAST PERIOD AND MODEL GUIDANCE STILL HAS QUITE A BIT OF SPREAD WITH THE AMPLITUDE AND PROGRESSIVENESS OF THIS FEATURE. HOWEVER...THIS PATTERN WILL PROBABLY BRING THE THREAT OF RAIN AND SNOW SHOWERS ACROSS THE AREA...BUT FOR NOW I HAVE KEPT THE SNOW CONFINED TO THE HIGHER TERRAIN. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... A WARM FRONT WILL MOVE ACROSS TONIGHT WITH SHRA AND POSSIBLY A RUMBLE OF THUNDER DEVELOPING ACROSS THE AREA...PRIMARILY OVER SE OH AND N WV. HAVE INCLUDED A PERIOD OF MVFR SHRA FOR THE TERMINALS TONIGHT WHILE CONFINING ANY MVFR CIGS TO N SITES. THERE COULD BE SOME BRIEF IFR VSBY IN THE HEAVIER SHRA...ESPECIALLY OVER SE OH...POSSIBLY AFFECTING KPKB. THE WARM FRONT WILL BE N OF THE REGION BY SUNDAY MORNING BUT A FEW ROUNDS OF WAA SHRA AND POSSIBLY THUNDERSTORMS CAN BE EXPECTED AS THE DAY PROGRESSES. CHANCES OF PRECIP HOWEVER REMAIN IN THE SCT CATEGORY...THUS KEEPING THE TAFS IN VFR. LIGHT TO MODERATE W TO SW FLOW ALOFT WILL BECOME LIGHT S TO SW OVERNIGHT AND CONTINUE INTO SUNDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: IFR VSBY OVERNIGHT IN RAIN COULD AFFECT ANY TAF SITE OVERNIGHT WITH KPKB AND KCKB STANDING THE BEST CHANCE. 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 22 23 00 01 02 03 04 05 06 07 08 09 EST 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 CRW CONSISTENCY H H H H H H H H M M M M HTS CONSISTENCY H H H H H H H H M M M M BKW CONSISTENCY H H H H H M M M M H M M EKN CONSISTENCY H H H H H H H H H H M M PKB CONSISTENCY H H H H H H H H M M M L CKB CONSISTENCY H H H H H H H H H H M M AFTER 00Z MONDAY... IFR POSSIBLE IN RAIN THROUGH MONDAY...BUT TIMING AND DURATION CONFIDENCES ARE LOW. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/TRM NEAR TERM...TRM/30 SHORT TERM...ARJ LONG TERM...MPK AVIATION...30