FXUS61 KILN 251331
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
831 AM EST FRI DEC 25 2009
.SYNOPSIS...
STRONG LOW PRESSURE LIFTING NORTH UP THE MISSISSIPPI VALLEY WILL
SWING AN OCCLUDED FRONT THROUGH THE REGION THIS AFTERNOON AND
EVENING. THE LOW WILL SLOWLY WEAKEN AS IT DRIFTS EASTWARD INTO THE
GREAT LAKES OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KILN SOUNDING AND TCMH DOPPLER RADAR HAVE INDICATED 70 KNOT WINDS
AT ABOUT 1000 FEET OFF THE SURFACE THIS MORNING. WITH THE
RELATIVE DRY SLOT BETWEEN WIDESPREAD RAIN TO THE EAST AND SHOWERS
TO THE WEST...SOME OF THESE WINDS WERE MIXING DOWN TO THE SURFACE
IN THE FORM OF 35 TO AROUND 40 KNOT GUSTS. THESE VALUES ARE JUST
BELOW OR AT WIND ADVISORY CRITERIA. HAVE DECIDED TO UPDATE THE
ZONES/GRIDS TO INCREASE WIND GUSTS FOR THIS MORNING IN THE 35 TO
45 MPH RANGE. GUSTS SHOULD DECREASE TO 20 TO 30 MPH THIS AFTERNOON
AS STRONG LOW LEVEL JET PIVOTS OFF TO THE NE AND SFC PRESSURE
GRADIENT RELAXES SOME. SINCE A 40 KNOT GUST WILL BE THE EXCEPTION
AND NOT THE NORM...HAVE HANDLED THE GUSTY WINDS IN A SPS THROUGH
NOON. THE REMAINDER OF THE PREVIOUS DISCUSSION BELOW IS STILL VALID.
OCCASIONAL SHOWERS ARE STILL OCCURRING FURTHER TO THE SOUTHWEST OF
THE CWFA AHEAD OF AN OCCLUDED FRONT THAT WILL SWING INTO THE OHIO
VALLEY THIS AFTERNOON. BREEZY CONDITIONS WILL PERSIST THROUGH
THE DAY ALTHOUGH THE TIGHT PRESSURE GRADIENT WILL RELAX IN THE
AFTERNOON. TEMPERATURES COULD BE TRICKY AS THERE IS THE POTENTIAL
FOR LITTLE TO NO DIURNAL RISE. BUT WITH BREAKS IN THE PRECIPITATION
BELIEVE THAT THERE SHOULD BE A SLIGHT INCREASE. GIVEN WARM
READINGS JUST TO THE SOUTH...HAVE GONE WITH TEMPERATURES CLOSER
TO WARMER GUIDANCE NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME PRECIPITATION MAY LINGER IN THE NORTHERN ZONES THIS EVENING
UNTIL THE OCCLUDED FRONT PUSHES NORTH OF THE AREA. COULD SEE SOME
SNOW MIX IN BEFORE PRECIPITATION ENDS. AS LOW PRESSURE SPINS IN
THE UPPER MIDWEST...THERE IS THE POSSIBILITY OF SOME PIECES OF
ENERGY BEING SHED TO PRODUCE LIGHT SNOW SHOWERS OR FLURRIES IN THE
WESTERN ZONES SATURDAY AND SATURDAY NIGHT. THIS ONLY WARRANTS LOW
CHANCE POPS. BUT AS THE LOW OPENS UP AND MOVES INTO THE GREAT
LAKES...00Z MODELS SHOW REASONABLE AGREEMENT ON SWINGING A
TROUGH THROUGH THE FORECAST AREA SUNDAY AFTERNOON AND EVENING.
THIS WILL BRING A MUCH BETTER CHANCE OF SNOW WITH SOME LIGHT
ACCUMULATION POSSIBLE. GENERALLY FAVORED WARMER GUIDANCE FOR LOWS
AND COOLER GUIDANCE FOR HIGHS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
CHANCE OF SNOW SHOWERS WILL CONTINUE INTO MONDAY AND MONDAY NIGHT
AS A SECONDARY TROUGH ROTATES THROUGH THE REGION. THEN HIGH
PRESSURE WILL BUILD IN FOR TUESDAY AND MOVE OFF TO THE EAST ON
WEDNESDAY. A COLD FRONT WILL MOVE INTO THE GREAT LAKES AND OHIO
VALLEY ON THURSDAY BRINGING THE NEXT CHANCE OF SNOW SHOWERS.
TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AND GUSTY WINDS WILL CONTINUE AT TAF SITES. AN
AREA OF LOW PRESSURE LOCATED OVER EXTREME SE PORTIONS OF IOWA WILL
CONTINUE TO MOVE TO THE NORTH. ALTHOUGH SOLID SHIELD OF
PRECIPITATION IS BEGINNING TO MOVE AWAY FROM THE TAF SITES...MORE
RAINFALL OVER INDIANA WILL MOVE INTO THE AREA. SOME MVFR VISBYS
WILL BE POSSIBLE WITH THIS RAINFALL. MVFR CIGS ALREADY AT SOME TAF
SITES WILL BEGIN TO IMPACT THE REST OF THE TAF SITES WITHIN AN
HOUR OR TWO. OCCLUDED FRONT WILL MOVE THROUGH LATE THIS AFTERNOON
INTO THE EARLY EVENING HOURS. AS IT MOVES THROUGH WINDS WILL SHIFT
TO THE SW...HOWEVER THEY WILL REMAIN GUSTY. COLDER AIR WILL BEGIN
TO FILTER INTO THE AREA. BY THIS TIME PRECIPITATION ACTIVITY WILL
BE MORE SPOTTY AND THEREFORE WENT VCSH BEFORE ENDING PRECIP. CIGS
WILL GRADUALLY BEGIN TO RISE DURING THE NIGHT FRIDAY NIGHT HOWEVER
MOST TAF SITES WILL STAY IN THE MVFR RANGE.
OUTLOOK...MVFR CIGS POSSIBLE SATURDAY INTO MONDAY. MVFR/IFR
VSBYS POSSIBLE SUNDAY INTO SUNDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HICKMAN
SHORT TERM...
LONG TERM...
AVIATION...NOVAK
