864 FXUS61 KRLX 161801 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 101 PM EST SUN NOV 16 2014 .SYNOPSIS... NEXT SYSTEM WITH DEEPER MOISTURE TODAY INTO MONDAY. SNOW LINGERS BEHIND THE SYSTEM INTO TUESDAY. COLDEST TEMPERATURES OF THIS NOVEMBER FREEZE ARRIVES LATE MONDAY INTO TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... 830 AM UPDATE...NO CHANGES NEEDED TO FORECAST. PREVIOUS DISCUSSION BELOW... THERE ARE SOME ECHOES SHOWING UP ON RADAR PROGRESSING THRU W ZONES...IN ASSOCIATION WITH A PROGRESSIVE WEAK MID LEVEL DISTURBANCE. HAVE SOME SCT FLURRIES IN REMAINDER OF OVERNIGHT HOURS. NOT SURE HOW MUCH WILL ACTUALLY SURVIVE THE TRIP THROUGH THE DRY LOWER ATMOSPHERE THOUGH. HOWEVER...THERE WERE SOME FLURRIES OBSERVED AT HTS IN THE LAST HR. THE MAIN STORY WILL THE ARRIVAL OF THE WELL ADVERTISED SYNOPTIC SYSTEM TONIGHT. THE UPPER FLOW WILL BEGIN TO AMPLIFY ACROSS THE AREA TODAY WITH BUILDING HEIGHTS IN RESPONSE TO UPSTREAM TROF AMPLIFICATION. THIS WILL RESULT IN INCREASING SW FLOW ALOFT AND WAA. WILL BE TRACKING ONE IMPULSE RIDING IN SW FLOW LATER THIS AFTERNOON OUT OF TN VALLEY. MODELS SHOW A GOOD SHOT OF MAINLY MID LEVEL LIFT WITH THIS WITH A LOW LEVEL BAROCLINIC ZONE BEGINNING TO TAKE SHAPE OVER THE REGION. USED A BLEND OF HI RES WRF AND HRRR FOR TIMING POPS WHICH ALLOWS PRECIP TO RACE NE INTO SW VA BY 18Z. THIS AREA OF PRECIP WILL CONTINUE TO LIFT NE TO COVER S HALF OF WV BY 21Z AND INTO NE KY AND SE OH SHORTLY THEREAFTER. CONTINUED THIS TREND ACROSS THE N LOWLANDS AND N MOUNTAINS WITH PRECIPITATION REACHING THOSE AREAS BY 00Z IF NOT A LITTLE SOONER. MODEL SOUNDINGS AND LOW LEVEL THERMAL PROFILES SUPPORT RAIN WITH THE INITIAL SURGE...EXCEPT A COUPLE HOURS OF PERHAPS SOME MIXED PRECIP IN POCAHONTAS CO. USED A BLEND OF LAMP/NAM/HRRR FOR TEMPS TODAY WHICH SHOWS MOST AREAS CRACKING 40 DEGREES WITH SOME MID 40S FOR SW VA AND S COAL FIELDS. THE HIGH TERRAIN SHOULD REBOUND INTO THE 30S. A MORE POTENT UPPER LEVEL SYSTEM AND SURFACE WAVE WILL BE TAKING SHAPE OVER THE DEEP SOUTH THIS EVENING AND RACING INTO TN VALLEY AND OUR AREA OVERNIGHT. THIS WILL BE THE MAIN SHOW LATE TONIGHT WITH WIDESPREAD PRECIP OVER THE AREA. WHERE THE LOW LEVEL BAROCLINIC ZONE SETS UP WILL BE KEY FOR WINTER WX PLACEMENT. THE TREND IN THE 00Z MODELS HAS BEEN TO SHIFT THIS A BIT FURTHER NW...MORE INTO C AND N OH. ALTHOUGH THE GFS CONTINUES TO RUN ON THE COLDER SIDE...IT IS MUCH CLOSER TO HI RES WRF/MESO NAM/SREF AND REGIONAL GEM WITH CRITICAL THERMAL PROFILES. THIS WOULD ESSENTIALLY MEAN RAIN FOR SE OH TONIGHT EXCEPT FOR N PORTION OF PERRY CO WHERE THERE IS GOOD AGREEMENT ON A TRANSITION TO WET SNOW LATE. REMARKABLY...ALL OF THE AFOREMENTIONED MODELS ARE NEARLY IDENTICAL WITH SNOW ACCUMULATION AXIS...KEEPING BULK OF SNOW ACCUMULATIONS TO JUST W OF CMH/ILN AND N OF PIT IN THE COLD SECTOR CLOSER TO UPPER TROF. I DID ALLOW UP TO AN INCH FOR NW PORTION OF PERRY COUNTY BY 12Z. AS THE WAVE PASSES...THE FLOW WILL BEGIN TO TURN MORE W...WITH COLDER AIR BEGINNING TO MARCH E TOWARD W ZONES. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... COLDER AIR WILL MOVE IN BEHIND THE COLD FRONT ON MONDAY...ALLOWING FOR A TRANSITION TO SNOW. COULD BE A DECENT BURST OF SNOW BEFORE PRECIPITATION BRIEFLY TAPPERS OFF. WITH WET GROUND AND TEMPERATURES ABOVE FREEZING HOWEVER...THINK GROUND ACCUMULATIONS WILL REMAIN SMALL. COLDER 850 MB AIR THEN MOVES IN LATE MONDAY AND MONDAY EVENING...MAKING THE LOWER ATMOSPHERE AUTO CONVECTIVE. EXPECT A GOOD SNOW BURST ON THE FRONT EDGE OF THIS COLDER AIR. SURFACE TEMPERATURES SHOULD BE COLD ENOUGH AT THIS POINT FOR SOME ACCUMULATION TO OCCUR. THE HEART OF THE ARCTIC AIR ARRIVES BY TUESDAY MORNING. WITH 850 MB TEMPERATURES OF -18 C...EXPECT THAT ANY CLOUD COULD PRODUCE SOME LIGHT SNOW/FLURRIES. WARM AIR ADVECTION FINALLY STARTS LATE TUESDAY NIGHT...WHICH SHOULD BRING AN END TO THE PRECIPITATION. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... PERIOD BEGINS WITH FCST AREA IN THE ARCTIC AIR...WITH A LARGE...DEEP UPPER LEVEL TROUGH RIGHT OVERHEAD. FLURRIES ARE LIKELY IN THE LOW LEVEL MOISTURE ALMOST UNTIL THE LAST CLOUD IS GONE WITH GOOD DENDRITE GROWTH TEMPERATURES ABOUT DOWN TO THE SFC. HIGH PRESSURE PASSING S OF THE AREA MAY PROVIDE GOOD RADIATIVE COOLING CONDITIONS LATE TUE NT...TOWARD DAWN WED...AS THE CLOUDS DISSIPATE. THE HIGH EXITS QUICKLY WED...AS THE NEXT COLD FRONT APPROACHES. IT CROSSES WED NT...WITH NOTHING MORE THAN A FEW FLURRIES AGAIN IN THE ARCTIC AIR...KEPT THIS PORTION OF FCST DRY FOR NOW. MODELS SHOW THE L/W TROUGH HANGING ON DEEPER / LONGER MOVING INTO THE LATER PORTION OF THE WEEK. ECMWF IS LONE MODEL IN SHOWING AN UPPER LEVEL S/W TROUGH MOVING THROUGH ON FRI. BY THIS TIME...THE L/W TROUGH OVER THE CENTRAL AND ERN CONUS IS FINALLY BEGINNING TO LIFT OUT...WITH SRN STREAM ENERGY CRASHING INTO THE PACIFIC COAST. ROLLED WITH WPC ENSEMBLE IDEA OF NOT LATCHING ON TO ANY ONE PARTICULAR S/W TROUGH IN SAID SRN STREAM GIVEN THE OVERALL DE-AMPLIFICATION OF THE LARGE SCALE FLOW. AS SUCH HAVE LOW CHC POPS THU NT INTO SAT. HIGH PRESSURE OF AT LEAST PARTIAL ARCTIC ORIGIN ARRIVES TO START THE WEEKEND. BLENDED IN WPC TEMPERATURES FOR LOWER HIGHS THAN PREVIOUS WITH THE SLOWER DE-AMPLIFICATION DEPICTED LATE WEEK. FOR LOWS...BLENDED IN THE MEX BUT FOR LITTLE CHANGE WED MORNING...AND THEN AVERAGED IN BIAS CORRECTED BLENDS FOR THE BEGINNING AND END OF THE DAY 4-7 PERIOD...AND THEN WPC IN BETWEEN...FRI AND SAT MORNINGS...THE MAIN CHANGE LOWER LOWS SAT MORNING AS WE MANAGE ONE MORE SHOT OF COLD AIR. BELOW NORMAL THROUGHOUT THE PERIOD...WELL BELOW NORMAL ON HIGHS DAYS 4-7...BUT RECORD LOWS DAY 3 NT / WED MORNING AS EXISTING RECORDS ARE MOSTLY SOFTER THAN THOSE FLIRTED WITH / BROKEN THIS MORNING. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... LOWERING CIGS...ALONG WITH PRECIPITATION WILL OVERSPREAD THE AREA...MAINLY AFTER 20Z. BULK OF PRECIPITATION WILL BE ACROSS WEST VA AND SOUTHWEST VA THROUGH 00Z...AND IN THE FORM OF RAIN. EXPECTING WIDESPREAD MVFR CIGS TO OVERSPREAD THE AREA...GENERALLY AFTER 00Z. RAIN WILL GRADUALLY CHANGE TO SNOW...FROM WEST TO EAST PARTICULARLY AFTER 06Z...WITH LOCAL IFR VSBYS/CIGS DEVELOPING. IN ADDITION...WINDS WILL BE GUSTY AT TIMES...PARTICULARLY ACROSS THE HIGHER TERRAIN WHERE GUSTS OF UP TO 40 KTS ARE POSSIBLE. GENERALLY EXPECTING GUSTS AROUND 24 KTS ACROSS THE LOWLANDS...DEVELOPING AFTER 15Z MONDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: MEDIUM ALTERNATE SCENARIOS: TIMING PRECIP THIS AFTERNOON COULD VARY A FEW HOURS. TIMING OF MVFR/IFR CIGS AND VSBYS COULD VARY FROM 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 18 19 20 21 22 23 00 01 02 03 04 05 EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY M M M M M M M H M H M H HTS CONSISTENCY H M M M M H H H H H H H BKW CONSISTENCY M M M M M M M M M L L H EKN CONSISTENCY H M M M M M M M M L L H PKB CONSISTENCY H H H M M M H H H H H H CKB CONSISTENCY H H H M M M H H H M H H AFTER 18Z MONDAY... IFR POSSIBLE MONDAY NIGHT INTO TUESDAY IN PRECIPITATION AND CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/RPY/30 NEAR TERM...SL/30 SHORT TERM...RPY LONG TERM...TRM AVIATION...SL