FXUS61 KILN 111133
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
633 AM EST FRI DEC 11 2009

.SYNOPSIS...
HIGH PRESSURE OF CANADIAN ORIGIN WILL CONTINUE TO PROVIDE COLD
AND DRY WEATHER TODAY. THIS HIGH WILL SLIDE OFF TO THE EAST ON
SATURDAY... ALLOWING SOME MODERATION TO TEMPERATURES. PRECIPITATION
WILL DEVELOP ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS AN
UPPER LEVEL DISTURBANCE TRACKS THROUGH THE OHIO VALLEY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BROAD MID LEVEL TROF EXTENDS EAST OF THE ROCKIES ACROSS THE GREAT
LAKES AND INTO NEW ENGLAND. SURFACE HIGH PRESSURE OF CANADIAN
ORIGIN WILL BUILD ACROSS THE TN VALLEY IN THE REGION OF MID LEVEL
CONFLUENCE. EXPECT MAINLY CLEAR CONDITIONS WITH A GOOD DEAL OF
SUNSHINE TODAY. ALTHOUGH WAA KICKS IN TODAY...AFTER A COLD START
PREFER TEMPS CLOSER TO COLDER MET GUID NUMBERS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
MID/UPR LEVEL FLOW BACKS MORE WESTERLY WITH EMBEDDED S/W TRACKING
FROM THE CENTRAL PLAINS INTO THE MID MS VLY SATURDAY NIGHT AND ACROSS
THE OHIO VALLEY SUNDAY. 

SFC HIGH PRESSURE SHIFTS EAST TONIGHT WITH SOME INCREASE IN HIGH
LEVEL MOISTURE. HAVE GENERALLY TRENDED TONIGHTS TO A BLEND
BETWEEN COLDER MAV GUID NUMBERS AND WARMER MET. 

ON THE BACK SIDE OF THE DEPARTING HIGH A RETURN FLOW BEGINS TO 
DEVELOP ON SATURDAY. EXPECT TO SEE AN INCREASE IN MID AND HIGH
LEVEL CLOUDS AND SOME MODERATION TO THE TEMPERATURES. MAV GUIDANCE
APPEARS A LTL TOO AGGRESSIVE WITH TEMPS AND PREFER A COMPROMISE
BETWEEN WARMER MAV AND COOLER MET GUID.

ISENTROPIC LIFT DEVELOPS SATURDAY NIGHT AHEAD OF THE AFOREMENTIONED 
S/W. NUMERICAL MODEL SOLN/S IN GOOD AGREEMENT SHOWING FAVORABLE 
LIFT AND MOISTURE DEVELOPING BETWEEN 06Z AND 09Z SUNDAY. WL BUMP UP
POPS INTO CATEGORICAL AND LKLY CATEGORIES LATE SAT NIGHT INTO
SUNDAY.

UNDER GOOD WAA TEMPS ALOFT ARE SUFFICIENTLY WARM FOR LIQUID BUT A 
DRY LOW LEVEL WITH LOW LEVEL WET BULB VALUES BELOW FREEZING SUGGEST 
THAT AT THE ONSET PRECIP MAY FALL AS A BRIEF PERIOD OF FREEZING 
RAIN. SRN PORTION OF ILN/S FA SHUD SEE A CHANGE TO ALL RAIN TOWARD 
SUNRISE SUNDAY AS WARMER IN THE LOW LEVELS ADVECTS IN. WL CHANGE
REMAINDER OF FA OVER TO RAIN SUNDAY MORNING FROM SOUTH TO NORTH.
SINCE TEMPS WARM UP ABOVE FREEZING ON SATURDAY AND THE PERIOD OF
FREEZING PRECIP WL BE LIMITED WL JUST CONTINUE A MENTION OF THIS
POSSIBILITY IN THE HWO.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SUNDAY STARTS OUT WITH A GOOD BIT OF ISENTROPIC LIFT AND SOUTHERLY 
FLOW OVER OHVLY...WRINGING OUT SOME RAIN EARLY. SURFACE TEMPS ARE 
TICKLING THE 30-32 DEG RANGE OVER THE NORTH HALF AND INSTEAD OF 
BUMPING THEM HIGHER...DECIDED TO FCST THE FREEZING RAIN. SNOW IS NOT 
REALLY GOING TO BE A POSSIBILITY HERE DUE TO WARM AIR ALOFT SO ITS A 
RAIN EVENT DEPENDENT ON SFC TEMPS. THE LIFT SOURCE QUICKLY MOVES 
NORTHEAST WITH WHAT APPEARS TO BE A WARM FRONT AND PRECIP CHANCES 
AND CLOUD COVER WILL CUT OFF LATER IN THE DAY AS WAA SETTLES IN. 

SUN NIGHT TEMPS COULD GO EITHER WAY WITH WAA AND CLEAR SKIES. LESS 
OF ONE AND MORE OF ANOTHER WOULD ALLOW FOR RADIATIONAL COOLING OR A 
CLOUDY AND SOMEWHAT MILD NIGHT. WENT MIDDLE OF THE ROAD ON FORECAST 
FROM MID 30S NORTH TO UPPER 30S SOUTH. 

LOW PRESSURE TRACKS THROUGH THE GTLKS AREA AND A COLD FRONT CROSSES 
OHVLY EARLY TUESDAY. TEMPS WERE MILD AHEAD OF IT AND THE PRECIP 
SHOULD END BEFORE ENOUGH COLD AIR FILTERS IN TO SUPPORT A CHANGE IN 
PTYPE. HIGH PRESSURE BUILDING IN THE MIDWEST WILL ALLOW FOR 
NORTHERLY WINDS TO KEEP A COLD AIRMASS OVER THE REGION FOR THE 
REMAINDER OF THE WEEK. LAKE EFFECT/ENHANCED SNOW SHOWERS WILL BE A 
POSSIBILITY ON TUES AND OVERNIGHT...BUT I KEPT FCST DRY SINCE THESE 
WILL BE FEW AND FAR BETWEEN. HIGH SETTLES INTO OHVLY WED NIGHT... 
ALLOWING THE AIRMASS TO MODERATE SLIGHTLY FOR THE END OF THE FCST 
PERIOD.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. SKIES WILL BE
MAINLY CLEAR TO START...WITH INCREASING HIGH CLOUDS TOWARD THE END
OF THE FORECAST. WINDS WILL STAY OUT OF THE SOUTHWEST...WITH GUSTS
OVER 20 KNOTS DURING THE AFTERNOON AT NORTHERN TAF SITES. WINDS
WILL SHIFT TO SOUTHEAST AT CVG AFTER 13Z SATURDAY. 

OUTLOOK...LIGHT FREEZING RAIN POSSIBLE LATE SATURDAY NIGHT INTO
SUNDAY MORNING. MVFR CEILINGS POSSIBLE SATURDAY NIGHT AND SUNDAY
AND THEN AGAIN MONDAY NIGHT AND TUESDAY. GUSTY WEST NORTHWEST
WINDS POSSIBLE TUESDAY.

&&

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

&&

$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...FRANKS
AVIATION...CONIGLIO