000 FXUS61 KILN 060853 AFDILN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 353 AM EST FRI FEB 6 2009 .SYNOPSIS... HIGH PRESSURE ACROSS THE UPPER OHIO VALLEY WILL PUSH OFF TO THE EAST TODAY. AS IT DOES...INCREASING SOUTHERLY FLOW WILL PULL WARMER AIR UP INTO THE REGION THIS AFTERNOON INTO SATURDAY. A COLD FRONT WILL THEN PUSH DOWN INTO THE AREA ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SURFACE HIGH PRESSURE WILL CONTINUE TO PUSH OFF TO THE EAST TODAY. ON THE BACK SIDE OF THE HIGH...LOW LEVEL SOUTHWESTERLY FLOW WILL BEGIN TO INCREASE THROUGH THE AFTERNOON. THIS WILL LEAD TO A DEVELOPING WAA PATTERN ACROSS THE AREA. THE 00Z GFS AND 00Z NAM STILL HAVE DISAGREEMENTS ON HOW TO HANDLE LOW LEVEL MOISTURE FIELDS FOR THIS AFTERNOON. THE GFS CONTINUES TO BE MUCH MORE MOIST BELOW 925 MB COMPARED TO THE NAM. THIS IS TROUBLING IN THAT THE NAM IS USUALLY THE MODEL THAT OVERDOES THE LOW LEVEL MOISTURE FIELDS. THE GFS MAY BE RESPONDING TO SOME MELTING OF THE SNOW PACK. SINCE SURFACE FLOW REMAINS FAIRLY LIGHT THROUGH THIS AFTERNOON...THINK WAA WILL BE TEMPERED AT LEAST TO A DEGREE BY THE SNOW ON THE GROUND SO HAVE OPTED TO STAY NEAR GUIDANCE FOR HIGHS TODAY ACROSS THE NORTH AND EVEN A LITTLE BELOW IN THE SOUTH. THUS...NOT SURE HOW MUCH OF AN EFFECT THE MELTING WILL HAVE ON THE LOW LEVEL MOISTURE TODAY. WILL THEREFORE LEAN TOWARD THE DRIER NAM AND KEEP THINGS MOSTLY SUNNY TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... LOW LEVEL MOISTURE DISCREPANCIES CONTINUE INTO THIS EVENING BETWEEN THE NAM AND GFS...BUT THE NAM BEGINS TO LOOK MORE LIKE THE MORE MOIST GFS BY 12Z SATURDAY MORNING. AS A RESULT...WILL ALLOW FOR A GRADUAL INCREASE IN CLOUDS THROUGH THE OVERNIGHT PERIOD...ESPECIALLY FOR THE NORTHWEST HALF OF THE FA AS A LITTLE BIT OF DEEPER MOISTURE BEGINS TO WORK ITS WAY IN OVERNIGHT. THIS SOMEWHAT DEEPER MOISTURE THEN SLOWLY OVERSPREADS THE REST OF THE FA THROUGH THE DAY ON SATURDAY. WITH SOME CONTINUED WEAK LOW LEVEL ISENTROPIC LIFT...WILL CONTINUE WITH LOW CHANCE OF SHOWERS OVERSPREADING THE AREA FROM THE NORTHWEST LATER TONIGHT INTO SATURDAY. WITH CONTINUED SOUTHERLY FLOW/WAA AND POSSIBILITY OF SOME CLOUDS...THINK TEMPS WILL REMAIN FAIRLY STEADY OR DROP OFF JUST A FEW DEGREES OVERNIGHT. DEPENDING ON HOW MUCH MELTING OCCURS...WITH WARM/MOIST AIR MOVING OVER SNOW PACK...POSSIBILITY EXISTS FOR SOME FOG DEVELOPMENT AS WE GO THROUGH THE NIGHT. WILL GO A LITTLE WARMER THAN GUIDANCE FOR HIGHS ON SATURDAY AS LOW LEVEL SOUTHERLY FLOW INCREASES AND STRONGER WAA DEVELOPS. A COLD FRONT WILL DROP DOWN FROM THE NORTH AND PUSH INTO OUR AREA LATE SATURDAY NIGHT INTO SUNDAY MORNING. FORCING IS FAIRLY WEAK AND MOISTURE IS STILL SOMEWHAT SHALLOW SO WILL KEEP POPS RELATIVELY LOW. ANY PCPN SHOULD THEN BEGIN TO TAPER OFF FROM THE NORTH SUNDAY AFTERNOON AS DRIER AIR WORKS IN BEHIND THE FRONT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AN ACTIVE...UNSEASONABLY WARM FCST IS IN PLACE THROUGH MUCH OF THE PERIOD. AFTER THE FRONTAL PASSAGE...A RIDGING PATTERN WILL TEMPORARILY BUILD IN ACROSS THE CWA BEFORE GIVING WAY LATE ON MONDAY AS A LOW DEVELOPS ACROSS THE CNTRL PLAINS. AHEAD OF THE LOW...POPS BEGIN TO INCREASE MON NIGHT INTO TUES WITH ISENTROPIC LIFT AHEAD OF THE LOW AND WITH A WARM FRONT LIFTING ACROSS THE AREA ON TUESDAY. WENT WITH A GFS/ECMWF BLEND MONDAY AND TUESDAY...THEN LEANED MORE TOWARD THE GFS FOR THE REST OF THE FCST AS THE ECMWF BEGINS TO LAG IN TIMING AND SHIFT THE SFC LOW NWD INTO ERN CANADA. A CLOSED H5 LOW WILL DEVELOP ACROSS THE PLAINS AND LIFT NEWD INTO THE GREAT LAKES WEDNESDAY INTO LATE NEXT WEEK. THIS WILL ALLOW THE CHC FOR ONGOING PRECIP THROUGHOUT THIS PERIOD. WITH SWRLY FLOW ALOFT LATE MUCH OF NEXT WEEK...HIGHS WILL BE UNSEASONABLY WARM IN THE 40S/50S WITH LOWS RANGING FROM THE M30S TO M40S. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... SKC AND LIGHT SOUTHERLY WINDS WILL PREVAIL FOR THE FIRST HALF OF THE PERIOD. MAIN QUESTION THIS TAF PACKAGE IS HOW MUCH LOW LEVEL MOISTURE WILL DEVELOP LATER TODAY WITH WARM AIR ADVECTION OVER A MELTING SNOW PACK...AND WHETHER THIS MOISTURE WILL BE ENOUGH TO FORM IFR/MVFR LOW CLOUDS THIS AFTERNOON AND EVENING. FOR NOW...WILL HINT AT THIS POSSIBILITY WITH SCT LOW-END MVFR CLOUDS...BUT IT WILL LIKELY BE EITHER SKC OR A BKN MVFR/IFR DECK. THIS MOISTURE MAY ALSO FAVOR SOME SCATTERED FOG/BR...BUT WITH WINDS PICKING UP TOMORROW NIGHT...KEPT THIS OUT OF ALL TAF SITES EXCEPT KLUK. OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SATURDAY INTO SATURDAY NIGHT...THEN AGAIN TUESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JGL NEAR TERM...JGL SHORT TERM...JGL LONG TERM...RYAN/WOODRUM AVIATION...HAWBLITZEL