000
FXUS61 KILN 280007
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
707 PM EST MON DEC 27 2010
.SYNOPSIS...
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL BE SETTLING OVER THE
OHIO VALLEY THROUGH MID WEEK. A MID LEVEL DISTURBANCE WILL
UNDERCUT THE RIDGE THAT IS IN PLACE AND BRING THE CHANCE FOR RAIN
AND FREEZING RAIN BEGINNING LATE WEDNESDAY NIGHT INTO THURSDAY.
HIGH PRESSURE WILL RE-ESTABLISH ITSELF UNTIL A STRONG SYSTEM
BUILDS IN THE MIDWEST AND TAKES AIM ON THE OHIO VALLEY LATER ON
FRIDAY AND INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CLOUD COVER STREAMING OFF OF LAKE MICHIGAN WILL SLOWLY SPREAD EAST
SOUTHEAST TONIGHT WITH SKY COVER GENERALLY EXPECTED TO BE ON THE
DECREASE. THIS WILL HELP TEMPERATURES DIVE ONCE AGAIN INTO THE
TEENS FOR MOST OF THE FORECAST AREA. A WEAK MID LEVEL DISTURBANCE
MAY BRING SOME INCREASED CLOUD COVER TOWARDS DAYBREAK.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MID LEVEL SHORT WAVE AND ASSOCIATED STRONGER VORT MAXIMA CROSSES
FROM CENTRAL INDIANA AT 12Z TUES AND REACHES SERN OH BY 18Z. THIS
SHOULD ONLY RESULT IN A LITTLE BIT OF INCREASED CLOUD COVER IN A
GENERALLY PARTLY CLOUDY AIRMASS.
A LOWER LEVEL SHORTWAVE AT H8 THAT IS NOT SEEN IN THE H5 OR SFC
FIELDS MAY BRING ENOUGH COLD AIR AT THIS LEVEL TO PUT SOME
FLURRIES IN THE AIR ON TUESDAY. SINCE THE GFS IS THE ONLY MODEL
PAINTING ANY QPF OVER THE OHIO VALLEY AND THERE REMAINS A MEAN
HIGH PRESSURE RIDGE OVER US THAT IS ONLY BEING FLATTENED INTO A
ZONAL FLOW FROM THESE SHORTWAVES...I LEFT THIS OUT OF THE FORECAST
ATTM.
THE RIDGE AT THE SURFACE AND ALOFT BUILD BACK IN AND STRENGHTEN
FOR THE MIDDLE OF THE WEEK AS WARM AIR ADVECTS INTO THE REGION ON
SOUTHERLY WINDS AT THE SAME TIME THE ATMOSPHERE IS GIVEN A CHANCE
TO SEE SOME DIURNAL MODIFICATION UNDER AT LEAST SOME SUNSHINE
DURING THE DAYLIGHT HOURS.
SFC TEMPS MAY REMAIN COOL ENOUGH THAT AS A WEAKENING DISTURBANCE
PUSHES INTO THE MEAN RIDGE...SOME LIGHT FREEZING RAIN MAY OCCUR
WED NIGHT INTO EARLY THURSDAY. THINK THAT THE
CANADIEN/EUROPEAN/GFS WERE A LITTLE OVERZEALOUS WITH THE EXTENT OF
THE PRECIP SHIELD BUTTING INTO THE ESTABLISHED RIDGE...BUT THEY
WERE CONSISTENT WITHIN THEMSELVES THAT I DID NOT FEEL COMFORTABLE
LEAVING OUT THE MENTION THIS AFTERNOON.
TEMPERATURES WERE TWEAKED BETWEEN PREVIOUS FORECAST AND MODEL
GUIDANCE...ALL OF WHICH WERE WITHIN 2-3 DEGREES OF EACH OTHER FOR
ANY PERIOD THROUGH WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISENTROPIC LIFT WILL BE PRESENT ACROSS THE AREA THURSDAY
MORNING...BUT DEEPER MOISTURE EITHER REMAINS TO OUR WEST OR SHIFTS
QUICKLY OFF TO THE NORTH THROUGH THE DAY. AS A RESULT...WILL KEEP
POPS RELATIVELY LOW INTO FRIDAY WITH GENERALLY JUST 20-30 POPS
GOING. PTYPE WILL BE AN ISSUE AT THE START OF THE LONG TERM PERIOD
AS TEMPS WILL BE NEAR OR JUST BELOW FREEZING THURSDAY MORNING. WITH
WARM AIR ALOFT...EXPECT PCPN TO BE ALL LIQUID BUT -FZRA WILL BE
POSSIBLE UNTIL TEMPS CLIMB ABOVE FREEZING THROUGH LATE THURSDAY
MORNING. GOOD WAA WILL THEN PERSIST ACROSS THE AREA THROUGH FRIDAY
WHICH SHOULD ALLOW FOR A DECENT WARMUP FOR THE END OF THE WEEK.
MODELS HAVE COME INTO GOOD AGREEMENT WITH FRONTAL SYSTEM FOR THIS
WEEKEND. THE 12Z GFS AND BOTH THE 00Z/12Z ECMWF ARE PUSHING THE
FRONT THROUGH OUR AREA SATURDAY NIGHT. AHEAD OF THIS...EXPECT
WIDESPREAD PCPN TO OVERSPREAD THE AREA FROM THE WEST FRIDAY NIGHT
AND CONTINUE INTO SATURDAY. THE GFS IS HINTING AT A RIBBON OF VERY
WEAK ELEVATED INSTABILITY PUSHING ACROSS THE AREA LATE FRIDAY NIGHT
INTO SATURDAY MORNING. SUPPOSE THIS COULD LEAD TO AN ISOLATED
THUNDERSTORM...BUT WILL NOT MENTION IN FORECAST AS DIURNAL TIMING IS
UNFAVORABLE. THE MODELS ARE NOW MORE PROGRESSIVE WITH THE FRONT WITH
GOOD DRYING WORKING IN FROM THE WEST SATURDAY NIGHT. WILL THEREFORE
TAPER OFF PCPN FAIRLY QUICKLY BUT AS COOLER AIR MOVES IN...SUPPOSE
PCPN COULD BRIEFLY CHANGE OVER TO SNOW BEFORE ENDING. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION THROUGH EARLY NEXT WEEK...LEADING TO
DRY CONDITIONS BUT COOLER TEMPERATURES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MONITORING MVFR TO EVEN IFR CLOUDS OVER INDIANA AND IL IN AREA OF
WARM AIR ADVECTION...I SHARE THE CONCERN EXPRESSED BY ZID CWSU FOR
SUFFICIENT INVERSION WITH INCREASING DWPOINTS OVER A BLANKET OF
SNOW ENOUGH TO PRODUCE STRATUS AND EVEN SOME MVFR VSBY
RESTRICTIONS OVERNIGHT AND INTO THE 12-18Z TIMEFRAME. CONCERN IS
MAINLY OVER THE WESTERN TAF SITES...THOUGH HAVE ALSO INCLUDED A
08-10Z START TO SOME MVFR CIGS IN THE KCMH AND KLCK LOCATIONS.
DESPITE PLENTY OF DRY AIR FROM 925 AND UP...VERY SHALLOW LOW LEVEL
MOISTURE WILL POSE A PROBLEM THROUGH MUCH OF THE FIRST PART OF THE
PERIOD IN THE WEST. LATER ARRIVAL IN THE EAST...WITH A SHORTER
DURATION IN THE EAST.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...FRANKS
SHORT TERM...FRANKS
LONG TERM...JGL
AVIATION...JDR
