265 FXUS61 KRLX 090952 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 448 AM EST FRI JAN 9 2015 .SYNOPSIS... WINDY TODAY AS A COLD FRONT SWEEPS THROUGH WITH SNOW SHOWERS AND FLURRIES. DRIER ARCTIC AIR MASS TONIGHT. HIGH PRESSURE BUILDS IN OVERNIGHT INTO SATURDAY. MILDER AIR ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... IT HAS BEEN HARD TO KEEP PACE WITH THIS FAST FLOW PATTERN ON THE GRAVEYARD SHIFT THIS FRIDAY MORNING. AN 850 MB JET MAX AROUND 50 KNOTS AND SOME PCPN MOSTLY ALOFT...HELPED BRING DOWN INCREASING WIND GUSTS AFTER MIDNIGHT...MORE THAN EXPECTED...PROMPTING WIND ADVISORIES FOR SEVERAL MOUNTAIN COUNTIES UNTIL 18Z. A SECONDARY WIND MAX SHOULD OCCUR NEAR THE REINFORCING COLD FRONT AND IN ITS WAKE FOR 2 TO 4 HOURS. TEMPERATURES BOUNCED UP FROM THE TEENS TO NEAR FREEZING IN CENTRAL AND SOUTHERN WEST VIRGINIA WITH THAT INCREASE IN WIND AFTER MIDNIGHT. FOR EXAMPLE...EKN JUMPED FROM 19 DEGS TO 31 DEGS IN ONE HOUR. THINKING THE CALENDAR DAY MAXIMUM TEMPERATURE FOR TODAY HAS ALREADY OCCURRED. THE 12 HOUR MAXIMUM FOR THE DAYLIGHT HOURS WILL LIKELY BE THE 12Z TEMPERATURE. AT 09Z...THE REINFORCING COLD FRONT WAS APPROACHING CVG AND DAY. HAVE THIS FRONT RACING EAST TOWARD PKB-HTS BY 12Z AND EAST OF CKB AND CRW BY 14/15Z...AND CROSSING THE MOUNTAINS BY LATE MORNING. BANDS OF SNOW SHOWERS HAVE BEEN SEEN OVERNIGHT AHEAD OF THE FRONT...AND WAS LIBERAL WITH FLURRIES IN THE WAKE OF THE FRONT. STILL HAVE LESS THAN AN INCH OF DRY SNOW ACCUM BY DAWN FROM PERRY COUNTY...ACROSS THE ROUTE 50 CORRIDOR INTO THE CENTRAL MOUNTAINS. THAN AN 1 OR 2 IN THE CENTRAL WV MOUNTAINS TODAY...WITH AGAIN LESSER AMOUNTS ELSEWHERE. DIFFICULT TO FIGURE THE RATE OF TEMPERATURE FALL IN THE WAKE OF THE FRONT...BUT HAVE READING DOWN TO AROUND 10 BY LATE AFTERNOON IN SE OHIO AND TO NEAR ZERO ABOVE 4 THSD FT IN OUR MOUNTAINS. MARGINAL WIND CHILL ADVISORY FOR TONIGHT FOR NORTHERN LOWLANDS AND INTO THE CENTRAL WV MOUNTAINS. SINCE ONLY AN ADVISORY...MATCHED PBZ START TIME FOR EASIER PUBLIC DISSEMINATION...BUT FIGURED CRITERIA WOULD BE A FEW HOURS LATER. MINIMUM TEMPERATURES TONIGHT SHOULD NOT BE QUITE AS COLD AS WEDNESDAY MORNING. && .SHORT TERM /SATURDAY THROUGH MONDAY/... HIGH PRESSURE CROSSES CWA ON SATURDAY. HAVE WIND CHILL ADVISORY LINGERING EARLY SATURDAY MORNING...WHILE WINDS ARE STILL BLOWING A BIT ACROSS THE NORTH. AS THE HIGH MOVES OF TO THE EAST SATURDAY NIGHT INTO SUNDAY...WARM AIR ADVECTION KICKS IN. HAVE NON-DIURNAL TREND SATURDAY NIGHT IN THE MOUNTAINS...WITH A DECENT WARM UP EVERYWHERE SUNDAY. POPS BEGIN INCREASING LATE SUNDAY AS SW FLOW INCREASES MOISTURE. LOOKS LIKE CWA WILL BE PINCHED BETWEEN MORE ACTIVE SOUTHERN STREAM STORM TRACK AND ANOTHER QUICK MOVING SYSTEM CROSSING TO THE NORTH...AND DRIVING A COLD FRONT THROUGH ON MONDAY. HAVE LIKELY POPS IN THE MOUNTAINS...ON THE NORTHERN FRINGE OF SOUTHERN STREAM SYSTEM SUNDAY NIGHT. THEN LIKELY POPS ENTERING FROM THE NW WITH COLD FRONT ON MONDAY. USED A MODEL BLEND TO FIGURE WARM NOSE...RESULTING IN WINTRY MIX ACROSS SOUTHEAST OHIO AND NORTHERN WV SUNDAY NIGHT. HARD TO NAIL DOWN EXACT P-TYPE THIS FAR OUT...BUT COULD INCLUDE AREAS OF SNOW...SLEET AND FREEZING RAIN. HAVE A FEW HUNDRETHS OF ICE ACCUMULATION IN THESE AREAS SO WILL GO AHEAD AND PUT MENTION OF THIS INTO HWO. CURRENTLY THINKING MAIN THREAT WOULD BE AROUND THE US 50 CORRIDOR IN SE OH AND N WV AND THE NORTHERN MOUNTAINOUS COUNTIES OF WV. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... POTENTIALLY AN UNSETTLED PATTERN SETTING UP IN THE EXTENDED. A SPLIT FLOW PATTERN WILL MEAN AN ACTIVE S STREAM DOING BATTLE WITH N STREAM COLD AIR. APPEARS SEVERAL WEAK SYSTEMS IN THE S STREAM WILL HAVE TO BE MONITORED. A KEY PLAYER WILL BE STRENGTH OF COLD SURFACE HIGH PROGGED TO SET UP OVER THE GREAT LAKES. JUST HOW MUCH COLD AIR WILL BE SUPPLIED FOR THE S STREAM SYSTEMS TO WORK WITH REMAINS IN QUESTION ALONG WITH N EXTENT OF LIGHT PRECIP FROM S STREAM WAVES. HAVE GENERALLY FOLLOWED HPC GUIDANCE AT THIS POINT...INCORPORATING SOME DETAIL FROM LATEST ECMWF. ELECTED TO LEAVE OUT OF HWO FOR NOW UNTIL SOME OF THE DETAILS CAN COME INTO BETTER FOCUS. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... THE STRENGTHENING LOW LEVEL JET HAS MIXED DOWN TO THE GROUND AND CAUSED A MAJOR CHANGE IN OUR WIND FORECAST. DID INCLUDE SOME LLWS AT CRW FOR A FEW HOURS...BEFORE STRONGER WINDS AT SURFACE. HAVE SURFACE WIND GUSTS OF 30 TO 35 KNOTS POSSIBLE AT THROUGH ABOUT 20Z. HAVE THE REINFORCING ARCTIC FRONT SWEEPING THROUGH PKB-HTS 12Z TO 14Z...THEN THRU THE WV MOUNTAINS 16 TO 18Z. STILL HAVE THE CEILINGS LOWERING ALONG AND IN THE WAKE OF THE FRONT...WITH CEILINGS AROUND 2 THSD FT IN LOWLANDS...AND 1 TO 2 THSD FT OVER MOUNTAINS. HAVE THOSE CLOUDS BECOMING SCATTERED IN SOUTHEAST OHIO AND MID OHIO VALLEY AROUND HTS-PKB 00Z TO 06Z SATURDAY. SOME IFR IN SNOW SHOWERS WILL LIKELY DEVELOP OVER THE CENTRAL WV MOUNTAINS AFTER 15Z...BUT TRIED TO KEEP EKN MOSTLY MVFR IN SNOW SHOWERS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIO: BRIEFLY LOWER VSBY IN SNOW SHOWERS 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. DATE FRI 01/09/15 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H M H H M M M BKW CONSISTENCY H H H H H H H H H M M M EKN CONSISTENCY H M M M M M M H H H H H PKB CONSISTENCY H M M M H H H H H H M M CKB CONSISTENCY H M M H H H H H H H H H AFTER 12Z SATURDAY... IFR POSSIBLE SUNDAY NIGHT AND MONDAY IN MIXED PCPN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST SATURDAY FOR WVZ009>011-019-020-031-032-038>040-046-047. WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ035>040-046- 047. OH...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST SATURDAY FOR OHZ066-067-075-076-084. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/MZ NEAR TERM...KTB SHORT TERM...MZ LONG TERM...ARJ AVIATION...KTB