152 FXUS61 KRLX 061051 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 551 AM EST MON FEB 6 2012 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE PASSES LATE TODAY. HIGH PRESSURE TUESDAY. A COLD FRONT WITH AN UPPER DISTURBANCE TUESDAY NIGHT AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATED TO TWEAK SKY GRIDS AND HRLY TEMPS BASED ON CURRENT OBS. PREVIOUS DISCUSSION BELOW... EDGE OF LOW STRATUS JUST NOW EXITING DICKENSON CO IN SW VA AS OF 06Z. FG HAS FORMED IN THE RVR VALLEYS GENERALLY ALONG AND S OF I64 CORRIDOR AND MTN VALLEYS. FURTHER N AND W DRIER AIR IN THE FORM OF LWR SFC DWPTS HAS ADVECTED IN WITH ENOUGH OF A DEWPT DEPRESSION TO SUPPRESS MUCH IN THE WAY OF FG THUS FAR. EXPECT THAT GENERAL TREND TO HOLD REMAINDER OF THE NIGHT WITH DENSE FG FORMING ACROSS RVR VALLEYS ACROSS COAL FIELDS...SW VA...AND SOUTHERN MTN VALLEYS. AFOREMENTIONED STRATUS MAY TRY TO SNEAK BACK N INTO SW VA COUNTIES BY DAWN AS LLVL FLOW TURNS MORE SOUTHERLY AHEAD OF APPROACHING UPR LOW. SPEAKING OF WHICH...THERE HAS BEEN A TREND TO SLOW THIS THING DOWN A BIT FROM LAST NIGHTS THINKING. PREV SHIFT HAS GENERALLY CAPTURED THIS IDEA AND ONLY TWEAKS NEEDED TO TIMING OF CLDS AND SCHC POPS ACROSS THE SOUTH FOR LATER TDY. COLUMN BECOMES SATURATED TO NEAR H8 ACROSS FAR SOUTH. THIS COMBINED WITH SOME LIFT PROVIDED FROM DIV FROM APPROACHING UPR LOW SHOULD ALLOW VERY LIGHT PCPN TO BREAK OUT. STILL LOOKS AS THOUGH MANY PLACES ACROSS THE SOUTH WILL BE HARD PRESSED TO MEASURE...HENCE THE LOW POPS. HAVE HELD POPS OUT TIL AFTER 18Z ACROSS SW VA...AFTER 21Z FOR SOUTHERN MTNS...00Z CENTRAL MTNS. BL TEMPS ENSURE A LIQUID EVENT. ASSOCIATED CLOUD SHIELD IN FORM OF 3 TO 5 THOUSAND FT DECK EXPECTED TO MAKE IT TO PERHAPS JUST N OF I 64 CORRIDOR THIS AFTN AND OVER TO NORTHERN MTNS THIS EVE. SHOULD SEE SOMEWHAT OF A SHARP CLOUD LINE WITH NORTHERN LOWLANDS AND SE OH SEEING A MAINLY SUNNY SKY TDY. WILL ROLL WITH WARMER MAV ACROSS THE NORTH AND SE OH AND TWEAK DOWN THE NUMBERS ACROSS THE SOUTH WHERE CLDS SHOULD KEEP TEMPS IN CHECK. STILL MILD FOR FEB STANDARDS. SKY WILL CLEAR THIS EVE FROM W TO E WITH PASSAGE OF UPR LOW. HAVE CLDS CLEARING ALL LOCATIONS BY 09Z. TONIGHT WITH MTN CLDS FROM UPR LOW BECOMING EXODUS BY 09Z. SFC HIGH BUILDING IN OVERHEAD LATE MAY ALLOW FOR SOME PATCHY RVR VALLEY FG IN THE USUAL SUSPECTED AREAS. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... BOTH NAM AND GFS SHOWING DEEP MOISTURE WITH LIFT TUESDAY NIGHT INTO WEDNESDAY...SO INCREASED POPS TO HIGH CHANCE. BIG QUESTION WILL BE TEMPERATURES WHEN PRECIPITATION ARRIVES. WITH SOME RADIATION POSSIBLE TUESDAY EVENING...PRECIPITATION COULD TAKE THE FORM OF SNOW AT MANY LOCATIONS. BEST CHANCES OF THAT OCCURRING WOULD BE THE NORTHERN COUNTIES AND HIGHER ELEVATIONS OF THE MOUNTAINS. WITH WARM GROUND AND LIGHT PRECIPITATION AMOUNTS...ANY ACCUMULATIONS WOULD BE LIGHT. && .LONG TERM /FRIDAY THROUGH SUNDAY/... FRONT TO PASS...ALONG WITH VORT MAX TRAVELING THROUGH THE REGION. MOISTURE LACKING WITH THIS AND ONLY WENT WITH SLGT CHC POPS. TEMPS SHOULD BE WARM ENOUGH FOR ANY PRECIP TO BE LIQUID IN THE LOWLANDS WITH A MIX IN ACROSS THE NORTHERN ZONES AND MAINLY SNOW IN THE HIGHER ELEVATIONS OF THE NORTHERN MOUNTAINS BEFORE ENDING. HIGH PRESSURE THEN TAKES CONTROL THROUGH FRIDAY NIGHT...WITH TEMPERATURES BEING A MIX OF HPC AND MODEL GUID. A SOUTHERN SYSTEM WORKS ITS WAY NORTHEASTWARD ON SATURDAY...WITH INCREASING CLOUDS. THIS SYSTEM WILL THEN SLIDE ACROSS THE CAROLINAS KEEPING ANY PRECIP OUT OF AND TO OUR SOUTH. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... GENERALLY MVFR VSBY IN FG ACROSS RVR VALLEYS CENTRAL AND SOUTHERN WV...SW VA...AND MTN VALLEYS. EXCEPTION BEING KCKW OFF THE ELK RVR WHERE LIFR FG WILL LIFT BY 13Z. A SLIGHT NORTH WIND AT KBKW HAS ALOWED LIFR FG TO SNEAK INTO TERMINAL. THIS WILL LIFT BY 13Z AS WELL. UPR LOW APPROACHES LATE IN DAY WITH 4 TO 6 THOUSAND FOOT CIGS ADVANCING N INTO CENTRAL LOWLANDS AND NORTHERN MTNS AFTER 18Z. SOME VERY LIGHT PCPN POSSIBLE ACROSS SOUTHERN WV AND SW VA AFTER 18Z. HOWEVER CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN KBKW TAF ATTM. SYS EXITS MTNS AFTER 06Z...WITH CLRING FROM W TO E. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND INTENSITY OF FOG CENTRAL AND SOUTHERN AREAS. 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 11 12 13 14 15 16 17 18 19 20 21 22 EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY M M M M H H H H H H H H HTS CONSISTENCY M M H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY M M H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z TUESDAY... IFR POSSIBLE IN THE MOUNTAINS DUE TO SNOW SHOWERS LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...RPY/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...JS AVIATION...30