FXUS61 KILN 050318
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
1018 PM EST THU DEC 4 2008

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT THROUGH LATE
FRIDAY PROVIDING DRY CONDITIONS AND BELOW NORMAL TEMPERATURES.
A CLIPPER SYSTEM WILL DROP THROUGH THE REGION SATURDAY AND
SATURDAY NIGHT RESULTING IN SNOW SHOWERS.

&&

.NEAR TERM /THROUGH 6 AM FRIDAY/...
LARGE SFC HI PRES CONTINUES TO OVERSPREAD THE OH VLY TONIGHT.
SHEARING OUT MID LVL S/WV EXTNDG FROM THE CNTRL GRT LKS W/SW INTO
THE PLAINS STATES...WITH AREAS OF SCT/BKN SC AHEAD OF THE S/WV
AXIS DRIFTING ACRS THE REGION. HAVE SEEN FEW OBS INDCG FLURRIES
UNDERNEATH THE PATCHES OF SC FROM ERN ILLINOIS INTO NW OHIO. WITH
SUBTLE LIFT AHEAD OF THE S/WV...HAVE INSERTED THE CHANCE FOR A FEW
FLURRIES ALONG AND NORTH OF I-70 WHERE SC SHOULD BE IN GREATER
COVERAGE. FURTHER SOUTH...MAINLY CLR SKIES WERE OCCURRING THIS
EVNG WHICH HAD ALLOWED FOR TEMPS TO FALL QUICKLY INTO THE UPPER
TEENS IN A NUMBER OF LOCALES. LOWERED OVERNIGHT LOWS INTO THE MID
TEENS ACRS THE WHITEWATER/MIAMI VLYS BASED ON CURRENT OBS...BUT
THIS MAY NOT EVEN BE ENUF WITH KDAY ALREADY AT 16 DEG AS OF 03Z.
THINKING THAT SC CURRENTLY OVER WRN/CNTRL INDIANA MAY HELP SLOW
TEMP FALLS AS IT DRIFTS ACRS THESE REGIONS LATER TONIGHT.

ZONE AND GRID UPDATES OUT.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
SHEARED OUT MID LEVEL SHORTWAVE TO DROP THROUGH THE OHIO VALLEY
EARLY FRIDAY WITH SURFACE RIDGE BUILDING ACRS THE REGION. EXPECT
MAINLY MID/HI LEVEL CLDS ACRS THE SOUTH WITH STRATO CU CONFINED TO
THE FAR NORTH. GENERALLY EXPECT PARTLY SUNNY SKY CONDITIONS. WITH
8H THERMAL TROF OF -14/-16 DEG C SLIDING ACRS THE REGION EXPECT
HIGHS TO BE A LTL MORE THAN TWO CATEGORIES BELOW NORMAL. HAVE
TRENDED FCST HIGHS AT OR SLIGHTLY BELOW MAV GUIDANCE.

MID LEVEL FLOW BACKS ON FRIDAY NIGHT AHEAD OF NEXT CLIPPER SYSTEM
DIGGING INTO THE UPPER MS VLY. WAA DEVELOPS WITH FAVORABLE ISENTROPIC
LIFT DEVELOPING RESULTING IN AN INCREASE IN MID/HI LEVEL CLOUDS BETWEEN
06Z AND 12Z. HAVE OPTED FOR LOWS CLOSE TO WARMER MAV GUID.

CLIPPER SYSTEM TO DROP SE THROUGH THE GREAT LAKES SATURDAY/SATURDAY
NIGHT. ASSOCIATED SURFACE LOW TO TRACK THRU THE NORTHERN LAKES
WITH COLD FRONT PASSING THRU SATURDAY EVENING. NAM IS RATHER DRY
WHILE THE GFS GENERATES A LTL MORE IN THE WAY OF MOISTURE. FORCING
IS WEAK WITH THIS SYSTEM WITH THE BEST 8H CONVERGENCE ACRS THE
NORTH. EXPECT A LIGHT PRECIP EVENT WITH UP TO AN INCH OF SNOW
SATURDAY/SATURDAY NIGHT MAINLY ACROSS THE NORTH WHERE FAVORABLE
LAKE EFFECT FETCH DEVELOPS. ACRS THE SOUTH ONLY EXPECT A MINOR
DUSTING AT MOST. HAVE TRENDED POPS FROM LKLY NORTH TO CHC SOUTH.
HAVE NOT STRAYED TOO FAR FROM GUID TEMPS SAT/SAT NIGHT.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
ECMWF HAS DISPLAYED A FAIR AMOUNT OF CONSISTENCY BETWEEN RUNS AND
SEEMS MORE RELIABLE THAN THE FLUCTUATING GFS. FOR SUNDAY...EXPECT A
FEW LINGERING SNOW SHOWERS BEHIND A DEPARTING CLIPPER. HIGH PRESSURE
AND DRY AIR WILL SCOOT ACROSS THE REGION SUNDAY NIGHT AND MONDAY. A
TROUGH AND ASSOCIATED GULF MOISTURE WILL BRING THE LIKELIHOOD FOR
RAIN AND SNOW SHOWERS ON TUESDAY...CHANGING TO ALL SNOW BEHIND THE
TROUGH TUESDAY NIGHT AND WEDNESDAY. ANOTHER LOW IS PROGGED TO MOVE
UP THE APPALACHIANS ON THURSDAY WHICH MAY PROVIDE MORE SNOW SHOWERS
TO EASTERN LOCATIONS.

REGARDING TEMPERATURES...COLDER GFS HAS TRENDED UP TOWARD THE ECMWF.
CHILLY HIGHS IN THE 20S AND 30S ON SUNDAY WILL INCREASE TO THE NEAR
NORMAL 40S BY TUESDAY IN WARM ADVECTION AHEAD OF THE TROUGH. HIGHS
WILL PLUNGE BACK INTO THE 20S AND 30S BY THURSDAY ON THE COLD SIDE
OF THE TROUGH.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
MVFR BKN-OVC CIGS WILL CONTINUE TO PREVAIL AT CMH AND LCK
OVERNIGHT WITH PDS OF MVFR CIGS FOR KDAY THROUGH 5Z. A WNW FLOW
OFF OF LAKE MICHIGAN WILL CONTINUE TO ADVECT MOISTURE ACROSS THE
NORTHERN TERMINALS. HIGH PRESSURE WILL BUILD IN FROM THE
WEST...ALLOWING FOR CLEAR SKIES AND VFR CONDITIONS AT
ILN...LUK...AND CVG. VFR CIGS WILL ADVECT ACROSS THE TERMINALS
AFTER 5Z. AN UPPER LEVEL DISTURBANCE WILL CROSS THE TERMINALS ON
FRIDAY...ALLOWING FOR MVFR CIGS TO CONTINUE ACROSS THE NRN
TERMINALS INTO THE AFTN.

OUTLOOK...MVFR CIGS AND VSBYS POSSIBLE SATURDAY...SUNDAY AND AGAIN
TUESDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...AR
NEAR TERM...RYAN
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...WOODRUM



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