826 FXUS61 KRLX 082009 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 309 PM EST THU MAR 8 2012 .SYNOPSIS... COLD FRONT CROSSES THIS EVENING. COOLER FRIDAY AND SATURDAY AS HIGH PRESSURE BUILDS OUR WAY. MILDER SUNDAY AS THE HIGH DRIFTS SOUTHEAST. A MILD AND SHOWERY PATTERN RETURNS MONDAY AND TUESDAY. && .NEAR TERM /THROUGH FRIDAY/... TONIGHT...BEST LARGE SCALE FORCING FOR ASCENT MOVES ACROSS THE FORECAST AREA ROUGHLY BETWEEN 00Z-06Z AS REGION COMES UNDER INFLUENCE OF RIGHT ENTRANCE REGION OF STRENGTHENING 160KT 300MB JET STREAK TO THE NORTH. AT THE SURFACE...GENERAL CONSENSUS OF MODEL DATA DEPICTING THE COLD FRONT NEAR THE OHIO RIVER AROUND 00Z AND NEAR EASTERN CWA BORDER AROUND 03Z. PREVIOUS FCST STILL HAS GOOD HANDLE ON INITIAL TIMING OF POPS/QPF. HOWEVER...WITH RAPID DRYING IN LOWER/MID LEVELS BETWEEN 03Z-06Z WILL GO AHEAD AND END POPS FOR ALL LOCATIONS BY 06Z EXCEPT HIGHER TERRAIN WHERE WILL CONTINUE SLIGHT TO LOW CHANCE POPS THROUGH THE NIGHT. WILL DECREASE MINS BY A FEW DEGREES MAINLY ACROSS CENTRAL AND WESTERN ZONES WHERE SKIES WILL SCATTER EARLIER. FRIDAY...UPPER LEVEL TROUGH AXIS CONTINUES ON TO THE EAST WITH NORTHWEST FLOW ALOFT AND RISING HEIGHTS. SKIES WILL BECOME MOSTLY SUNNY...WITH THE EXCEPTION OF THE FAVORED UPSLOPE LOCATIONS OF COURSE WHERE ENOUGH LOW LEVEL MOISTURE WILL BE TRAPPED ON NORTHWEST SFC WINDS TO CONTINUE WITH PARTLY CLOUDY SKIES HERE. ALSO HAVE LOWERED MAXES A FEW DEGREES FROM PREVIOUS FCST WITH MODEL CONSENSUS DEPICTING H925 TEMPS OF ABOUT 1.5C AT 18Z WITH WEAK COLD ADVECTION CONTINUING DURING THE AFTERNOON. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... UPSLOPE COLD ADVECTION FLOW BEHIND REINFORCING COLD FRONT THAT SLIPS THROUGH THE AREA FRI AFTERNOON COULD BE JUST ENOUGH FOR SNOW FLURRIES BENEATH THE INVERSION IN THE NORTHERN WV MOUNTAINS FRI EVENING. ALSO INCREASED WINDS AND GUSTS THERE WITH THIS FLOW. ALSO NOT SURE HOW QUICKLY WINDS WILL DECOUPLE ACROSS THE AREA IN GENERAL AS HIGH PRESSURE TAKES UNTIL THE DAYLIGHT MORNING HOURS OF SAT TO BUILD IN. WEAK MID LEVEL WARM ADVECTION BRINGS ABOUT PATCHY MID AND HIGH CLOUD SAT AS SFC HIGH MOVES ACROSS. MODELS CONTINUE SLOWER TREND WITH SOUTHERN STREAM CLOSED OFF UPPER LEVEL LOW COMING NE OUT OF ITS TRANSIENT REX BLOCK AND INTO THE CENTRAL PLAINS OVER THE WEEKEND. THIS KEEPS DRY WEATHER GOING THROUGH SUN...WITH NOTHING MORE THAN AFTERNOON CU IN THE MOUNTAINS SUN WITH INCREASING MOISTURE IN LIGHT S FLOW. BLENDED IN ADJMET FOR LOWS FRI NT...NOT TAKING THAT LOW GUIDANCE HOOK LINE AND SINKER ON ACCOUNT OF DOUBT AS TO TIMING OF DECOUPLING. ALSO BLENDED IN ADJMET FOR HIGHS SAT TO REFLECT COOL AIR BENEATH SUBSIDENCE INVERSION...AND LOWS SAT NT WITH BETTER RADIATIVE COOLING. STILL HAVE FRI NT THE COLDER OF THE TWO BUT WOULD NOT BE SURPRISED TO SEE LOWS EVEN CLOSER ULTIMATELY. BLENDED IN ADJMET ON DEW PINTS AS WELL TO LOWER IN MOUNTAINS SAT AND INCREASE MORE SLOWLY SUN. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... CONTINUED OUR TREND TOWARD A SLOWER RETURN TO THE MOISTURE. SO HAVE DRY CONDITIONS HOLDING WELL THROUGH SUNDAY NIGHT...AND ALL NIGHT IN OUR EASTERN COUNTIES. SO ROUNDING OUT A DRY MARCH WEEKEND. MID LEVEL HEIGHTS ABOVE NORMAL OVER THE SOUTHEASTERN STATES. SO HAVE INITIAL FRONT WEAKENING IN THE OHIO VALLEY MONDAY AFTERNOON AND MONDAY NIGHT...AND NOT MOVING THROUGH. SO NO SIGNS OF ANY COLD AIR INTRUSION NEXT WEEK. THIS ALSO MEANT INCREASING DEW POINTS AND MILDER NIGHTS INTO MID WEEK. HOWEVER...SAME PATTERN CAUSES PROBLEMS WHEN...OR IF...TO REMOVE CHANCE POPS. ACCEPTED MOST HPC MEDIUM RANGE GUIDANCE FOR MONDAY INTO THURSDAY. MINIMUM TEMPERATURES INCREASE TO AROUND 50 DEGREES IN THE LOWLANDS DURING THIS PERIOD. AS USUAL FOR MARCH...MAXIMUM TEMPERATURES WILL BE HIGHLY DEPENDENT ON TIMING OF SHOWERS...BUT MID 60S TO LOWER 70S APPEAR WIDESPREAD. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... 18Z THURSDAY THROUGH 18Z FRIDAY BREEZY SOUTH/SOUTHWEST WINDS WILL CONTINUE THIS AFTERNOON AHEAD OF THE COLD FRONT. SHOWERS CURRENTLY LOCATED ALONG AND WEST OF THE OHIO RIVER WILL CONTINUE TO OVERSPREAD THE AREA THIS AFTERNOON. GENERAL MVFR CONDITIONS CAN BE EXPECTED WITH THESE SHOWERS WITH 2-3SM WITH 1K-2K CIGS. COLD FRONT SHOULD BE NEAR OHIO RIVER SITES AROUND 00Z AND NEAR OR THROUGH EASTERN SITES NEAR 03Z. A BRIEF PERIOD OF IFR CIGS IS EXPECTED NEAR AND BEHIND THE FRONT FOR A 2-3 HOUR PERIOD. WINDS SHIFT TO THE NORTHWEST WITH THE FRONT...WITH RAPIDLY IMPROVING CONDITIONS EXPECTED AT ALL BUT MOUNTAIN LOCATIONS BY 06Z...WITH ALL LOCATIONS AT VFR BY 12Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY... FORECAST CONFIDENCE...HIGH. ALTERNATE SCENARIOS: TIMING OF COLD FRONT AND ITS ASSOCIATED WIND SHIFT/IFR CEILINGS AND PRECIPITATION MAY DIFFER BASED ON SYSTEM PROGRESSION. 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 H H M M M H M L L L L H HTS CONSISTENCY H M M H H L L L L L H H BKW CONSISTENCY H H H L M M L M M M M M EKN CONSISTENCY H H M M H L M L L L L L PKB CONSISTENCY M H L H M M M M M H H H CKB CONSISTENCY H M M L L L L L L L L M AFTER 18Z FRIDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/TRM/50 NEAR TERM...50 SHORT TERM...TRM LONG TERM...KTB AVIATION...50