000 FXUS61 KRLX 130152 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 952 PM EDT MON MAY 12 2008 .SYNOPSIS... HIGH PRESSURE BUILDING IN TONIGHT AND TUESDAY. PERIODIC WEATHER SYSTEMS BRINGING UNSETTLED AND COOL WEATHER MIDWEEK THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... ONGOING FCST ON TRACK FOR THE MOST PART. ONLY CHG WAS TO INCLUDE SLGHT CHC POPS UNTIL 05Z...FOR EAST OF CRW AND LOGAN TO ACCOUNT FOR BAND OF LIGHT SHOWERS MOVING SSE OVER THE LOWLANDS AND CENTRAL MOUNTAINS. ...PREVIOUS DISCUSSION BELOW... AS LOW MOVES OFF TO NORTHEAST A FINAL NARROW STRING OF VORT MOVING ACROSS AREA FROM NORTH THIS EVENING. A FEW SHOWERS EXPECTED TO BE TRIGGERED TO THE NORTHEAST OF THIS VORT INTO THIS EVENING AS IT PASSES THROUGH THE REGION. AFTER THIS THE ATMOSPHERE DRIES WELL BRINGING CLEARING LATER TONIGHT. NO SIGN OF MOISTURE TUESDAY SO THERE WILL BE PLENTY OF SUN. NORTHERLY FLOW TONIGHT WILL MEAN PRETTY COLD TEMPERATURES. WITH SO MUCH MOISTURE IN THE GROUND THE TEMPERATURES SHOULD HOLD ABOVE FREEZING AS LOWER ATMOSPHERE RH HITS AROUND 100% AND DEW POINTS HOLD WITH SOME FOG FORMING. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... SPLIT FLOW PATTERN WITH AN ACTIVE SOUTHERN STREAM PREVAILS OVER THE CENTRAL AND EASTERN PART OF THE NATION THIS PERIOD. MODELS IN VERY GOOD AGREEMENT ON BRINGING ANOTHER COOL FRONT INTO THE OHIO VALLEY WEDNESDAY AFTERNOON AS NORTHERN STREAM SHORT WAVE MOVES ACROSS THE GREAT LAKES. THE FRONT THEN STALLS OVER OUR AREA WEDNESDAY NIGHT AS THE SHORT WAVE LIFTS OUT THROUGH NEW ENGLAND. A CLOSED LOW OVER THE SOUTHWESTERN U.S. OPENS UP AND EJECTS NORTHEASTWARD...SENDING A SURFACE WAVE NORTHEASTWARD ALONG THE FRONT THURSDAY AND THURSDAY NIGHT. WITH THE INITIAL FRONTAL DYNAMICS WEAKENING...RAINFALL FOR THE FRONT WEDNESDAY AND WEDNESDAY NIGHT LOOK MODEST. INSTABILITY WITH THE FRONT ALSO LOOKS MODEST...BUT DECIDED TO THROW CHANCE OF THUNDER WEDNESDAY AFTERNOON AND EVENING TO BETTER COORDINATE WITH SURROUNDING OFFICES. TEMPERATURES WILL BE NEAR NORMAL WEDNESDAY AS CLOUDS OFFSET AFTERNOON HEATING. FOR THE SURFACE WAVE THURSDAY AFTERNOON AND NIGHT...WENT HIGH CHANCE POPS INSTEAD OF LIKELY ONLY BECAUSE AT THIS TIME FRAME...THERE IS A LOT OF ROOM FOR ADJUSTING THE TIMING AND EXACT TRACK OF THE SURFACE WAVE. NEVERTHELESS...ALL MODELS SHOW A DECENT WAVE WILL AFFECT OUR AREA LATER IN THIS PERIOD. WITH THE GULF OF MEXICO OPEN AND GOOD UPPER SUPPORT ASSOCIATED WITH THIS WAVE...WE WILL HAVE TO MONITOR FOR POTENTIAL WATER PROBLEM IN THE LATE THURSDAY AND THURSDAY NIGHT TIME FRAME. WILL MENTION THIS IN HAZARDOUS WEATHER OUTLOOK. WITH ALL THE CLOUDS...TEMPERATURES WILL REMAIN NEAR NORMAL. && .LONG TERM /FRIDAY THROUGH MONDAY/... RIGHT NOW...MODELS HAVE THE SURFACE WAVE EXITING BY FRIDAY MORNING. HOWEVER...AS THE PATTERN EVOLVES FROM THE SPLIT FLOW TO AN UPPER TROUGH OVER THE EASTERN HALF OF THE U.S...ADDITIONAL REINFORCING SHOTS OF COOL AIR AND SHOWERS WILL KEEP THINGS ON THE UNSETTLED AND COOL SIDE INTO THE WEEKEND. HARD TO SPECIFY ANY EXTENDED DRY PERIOD IN THIS DEVELOPING COOL AND UNSTABLE PATTERN. BASICALLY SHOW SOME POPS EVERY DAY THIS PERIOD AND AT OR BELOW NORMAL TEMPERATURES...IN LINE WITH HPC. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... LOW LEVEL MOISTURE STILL STREAMING IN FROM THE NORTHWEST GIVING MVFR CEILINGS...BUT HTS HAS ALREADY LIFTED TO VFR AS DRY AIR SLOWLY MOVES IN. WITH SATURATED GROUND...WILL EXPECT FOG TO DEVELOP QUICKLY...ESPECIALLY IN RIVER VALLEYS...AND AT ALL TAF SITES UPON CLEARING OVERNIGHT. PRIMARILY THINKING IS THAT THIS WILL OCCUR BETWEEN 10Z AND 13Z. VFR EXPECTED UPON FOG DISSIPATION TUESDAY. AVIATION OUTLOOK /AFTER 00Z WEDNESDAY/...SOME IFR CONDITIONS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY WITH A FRONTAL BOUNDARY IN THE VICINITY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...AAR NEAR TERM...AAR/30 SHORT TERM...JMV LONG TERM...JMV AVIATION...AAR