FXUS61 KRLX 140528 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1228 AM EST TUE FEB 14 2012 .SYNOPSIS... A WEAK SYSTEM PROVIDES RAIN AND/OR SNOW OVERNIGHT AND TUESDAY. HIGH PRESSURE WEDNESDAY. LOW PRESSURE AND COLD FRONT BRING MORE UNSETTLED WEATHER WEDNESDAY NIGHT INTO THURSDAY NIGHT. DRY START TO WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 930 PM UPDATE... WITH A 9 KFT ALTOCU OVC IN PLACE...TEMPERATURES HAVE LIKELY STOPPED FALLING FOR THE NT OTHER THAN A LITTLE WET BULB COOLING ON PRECIP. WITH 88D SHOWING THE AC DECK...NOT A BAD IDEA TO HAVE AT LEAST SLIGHT CHANCE POPS FROM THE ONSET NOW SO NO CHANGES THERE ALBEIT WHEN SNOWFLAKES DO START TO REACH THE SURFACE IT IS NOT LIKELY TO ACTUALLY MEASURE FOR A LITTLE WHILE AT LEAST. 630 PM UPDATE... FCST ON TRACK SAVE FOR MINOR CHANGES TOP TEMPERATURES EARLY ON AND KNOCKING DOWN WIND SPEEDS SOMEWHAT OVERNIGHT. PREV DISCN... MODELS HAVE SOME MINOR DIFFERENCES WITH THE ARRIVAL OF THE APPROACHING SYSTEM. NAM IS QUICKER WITH THE MOISTENING OF THE LOW LEVELS...WHICH WOULD LEAD TO A SLIGHTLY EARLIER ARRIVAL OF THE RAIN/SNOW. CURRENT FORECAST MAINTAINS A GOOD COMPROMISE SOLUTION BETWEEN THE MODELS...SO WILL CONTINUE VERY CLOSE TO CURRENT PACKAGE. LOOKS LIKE PRECIPITATION WOULD BEGIN AS SNOW TONIGHT. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... 630 PM UPDATE...INCREASED CLOUD COVER TUE AND TUE NT PER LOW LEVEL MOISTURE IN THE LIGHT FLOW BENEATH LOWERING INVERSION AS WEAK LOW PRESSURE MOVES THROUGH. PREV DISCN... ANOTHER ROUND OF UNSETTLED WEATHER EXPECTED IN THE SHORT TERM PERIOD. SHORTWAVE TROUGH...CURRENTLY OVER THE CENTRAL PLAINS...WILL PUSH EAST INTO THE CWA TUESDAY. NOT A LOT OF MOISTURE EXPECTED DURING THIS PERIOD...WITH PW VALUES GENERALLY EXPECTED TO BE AROUND 0.5 INCHES...OR ABOUT AVERAGE FOR THIS TIME OF YEAR...AND LITTLE DYNAMICS. THUS...EXPECTING GENERALLY LIGHT PRECIPITATION AMOUNTS. PRECIPITATION WILL START AS SNOW MONDAY NIGHT/TUESDAY MORNING...PARTICULARLY ACROSS SOUTHEAST OHIO. SOME AREAS MAY TAKE A WHILE FOR THE AIR TO SATURATE ENOUGH BEFORE PRECIPITATION REACHES THE GROUND...SUCH AS MUCH OF THE WV LOWLANDS...AND THUS...SNOWFALL IS EXPECTED TO BE LIMITED IN THESE AREAS. HOWEVER...CANNOT RULE OUT MORNING SNOW SHOWERS IN THESE AREAS...WITH SOME LIGHT/DUSTING ACCUMULATIONS. BETTER ACCUMULATIONS EXPECTED OVER SOUTHEAST OHIO...WHERE UPWARDS OF AN INCH IS POSSIBLE...NOT ENOUGH TO MEET ADVISORY CRITERIA...SO NO HEADLINES WILL BE ISSUED. UPPER TROUGH WILL PUSH OFF TO THE EAST TUESDAY NIGHT...WITH DRY HIGH PRESSURE TRYING TO BRIEFLY TAKE HOLD. AS THE ATMOS DRIES OUT...COULD SEE A TRANSITION OVER TO DRIZZLE OR FREEZING DRIZZLE...ESPECIALLY ACROSS THE WESTERN 2/3 OF THE FCST AREA. FOR NOW...KEPT A MENTION OF SHOWERS IN THE FORECAST BUT ADDED "OR" DRIZZLE/FZ DRIZZLE WORDING. AT THIS POINT...NOT EXPECTING TOO MANY PROBLEMS FROM ANY FREEZING DRIZZLE...BUT THIS SHOULD BE MONITORED. AFTER A BRIEF BREAK IN THE PRECIPITATION FOR MUCH OF WEDNESDAY...ANOTHER SYSTEM WILL PUSH IN QUICKLY WEDNESDAY NIGHT/THU. PLENTY OF WARM AIR OUT AHEAD OF THIS SYSTEM WILL KEEP MUCH OF THE PRECIPITATION IN THE FORM OF RAIN. THIS SYSTEM WILL BE A BETTER RAIN PRODUCER...AS STRONG LOW LEVEL WINDS WILL AID IN MOISTURE TRANSPORT FROM THE GULF. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... SOME TIMING DIFF WITH FROPA NOTED ON MDLS FOR THU EVE. WILL LEAN WITH HPC THINKING TAKING A BLEND BETWEEN ECWMF/GFS WHICH AS FRONT JUST EAST OF CWA AT 00Z FRI. WILL DECREASE POPS RAPIDLY...KEEPING DETERMINISTIC POPS CONFINED TO THE NORTHERN MTNS. QUESTIONS ARISE TO HOW FAST CLRING TAKES PLACE. A DEVELOPING SUBSIDENCE INVERSION AMID SOME LINGERING LLVL MOISTURE MAY KEEP CLDS GOING MUCH OF THE NIGHT AND HAVE WORKED THE SKY GRIDS USING THIS THINKING. THIS ALSO MEANT GOING TOWARD THE WARMER SIDE OF GUIDANCE FOR MINT. KEPT LOWLANDS ENDING AS SHRA GIVEN BL TEMP CONUNDRUMS. HAVE LITTLE ACCUM IN THE MTNS BEFORE SHUTTING OFF BY 06Z. SFC HIGH BUILDS IN FOR FRI AND SAT. ANY LINGERING LOW CLDS SHOULD MIX OUT FRI FOR A RETURN TO SUNSHINE. MDLS HINTING AT A S/W TROF AXIS PASSING THRU SUN. MOISTURE LOOKS MEAGER AND ONLY HAVE SOME SCHC POPS ACROSS THE NORTHERN MTNS. TEMP PROFILES SUGGEST ANY SHSN WOULD BE IN THE HIGHER ELEVATIONS. COULD EASILY SEE THIS BEING MORE VIRGA THAN ANYTHING ELSE. ALL IN ALL...SHAPING UP TO BE A DECENT WEEKEND WITH ABV NORMAL TEMPS DURING THE DAY...AND SEASONABLE TEMPS AT NIGHT. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WARM FRONT AND UPPER LEVEL DISTURBANCE APPROACHES AND CROSSES TODAY. CLOUDS WILL LOWER AND THICKEN THIS MORNING. LIGHT SNOW WILL OVERSPREAD THE MIDDLE OHIO VALLEY TOWARD DAYBREAK....BRINGING MVFR CONDITIONS TO THE OHIO RIVER. HOW FAR E OF THE OHIO RIVER MVFR SNOW MAKES IT IS QUESTIONABLE...AS TEMPERATURES WILL CLIMB ABOVE FREEZING BY MID MORNING. CIGS WILL LOWER TO MVFR IN LIGHT RAIN TUE AFTERNOON FOR MOST OF THE AREA...WITH CIGS GETTING DOWN TO VERY NEAR IFR AT LEAST AS FAR E AS THE OHIO RIVER BY THE END OF THE TAF PERIOD...00Z WED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: HIGH REMAINDER OF TONIGHT...MEDIUM EARLY THIS MORNING THROUGH THE BALANCE OF THE DAY TODAY. ALTERNATE SCENARIOS: TIMING OF LOWERING CLOUDS AND RAIN/SNOW MAY VARY LATE TONIGHT AND TUE. EXTENT OF MVFR SNOW COULD BE GREATER TUE MORNING...WITH IFR NOT ENTIRELY OUT OF THE QUESTION. 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 TUE 02/14/12 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H H H M H H M M M HTS CONSISTENCY H H H H H H L M M M L L BKW CONSISTENCY H H H H H H M H M M M M EKN CONSISTENCY H H H H H H H H H M M M PKB CONSISTENCY H H H H M M M M M M M M CKB CONSISTENCY H H H H H H H H H H M M AFTER 06Z WEDNESDAY... IFR IN MIXED PRECIPITATION AND LOW CEILINGS TUESDAY NIGHT. THE LOW CEILINGS COULD LINGER INTO WEDNESDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/SL/RPY/30/MZ NEAR TERM...TRM/RPY SHORT TERM...TRM/SL LONG TERM...30/MZ AVIATION...KMC