FXUS61 KILN 291137
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
637 AM EST SUN NOV 29 2009
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL RETREAT TO THE EAST TODAY. A COLD
FRONT WILL CROSS THE REGION TONIGHT BRINGING A SHOT OF RAIN. HIGH
PRESSURE WILL TRY TO BUILD IN MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
00Z MODELS IN PRETTY GOOD AGREEMENT WITH THE DEVELOPMENT OF FEATURES
TODAY. AS H5 S/W DIGS THRU THE NRN MS VLY...A WEAK SFC LOW
DEVELOPS...THEN SFC LOW AND CDFNT PUSH UP THE OH VLY. ISENTROPIC
LIFT IS WEAK IN THE MRNG...BUT QUICKLY INCREASES DURING THE AFTN
MAINLY INTO WEST CENTRAL OHIO. MUCH OF THE DAY WILL BE DRY IN THE
NW WITH RAIN ONLY EXPECTED IN THE LAST FEW HOURS OF THE DAY. INCREASED
POPS IN THE NW TO HIGH CHC...BUT LEFT THE E DRY.
INCREASED HIGHS FOR TODAY. RAN A COMPROMISE BETWEEN THE MAV AND
MET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
FNT PUSHES QUICKLY ACRS THE FA TNGT. 00Z MODELS ARE CONSISTENT IN
PUSHING THE FNT THRU FA BETWEEN 00-06Z MON. MUCH OF THE PCPN IS
POST FRONTAL HOWEVER...SO THE BEST POPS WILL BE OVERNIGHT. UPPED
POPS TO CATEGORICAL.
MODELS HAVE THE FNT WELL INTO THE APPALACHIANS BY 12Z MONDAY...SO
ENDED TO CHC OF RAIN FROM NW TO SE TNGT AND MADE MONDAY DRY. AS
HIGH PRESSURE BUILDS INTO THE MID MS VALLEY THE FLOW OFF THE
LAKES BECOMES LESS CYCLONIC...SO DONT EXPECT INSTABILITY SHOWERS
ON MONDAY.
H5 S/W SWINGS ACRS THE FA MONDAY NIGHT. THE GFS IS THE STRONGEST
AND SHARPEST WITH THIS FEATURE AND PRODUCES QPF THE FARTHEST S. THE
ECMWF/UKMET AND GEM SHOW THIS FEATURE BUT NOT AS STRONG. KEPT THE
20 POPS ACRS THE NRN HALF. THICKNESSES WILL BE LOW ENUF THAT ANY
PCPN SHOULD FALL AS SNOW SHOWERS. NO MAJOR ACCUMULATION IS EXPECTED.
HIGH PRESSURE SHOULD BUILD IN FOR TUES.
GUIDANCE TEMPS LOOKED REASONABLE THRU THE PERIOD...SO DIDNT STRAY
TOO FAR
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE TO BEGIN PERIOD WITH SEASONABLY COLD TEMPS. HIGH
SHIFTS EAST BY WEDNESDAY. DEVELOPING LOW WILL SPREAD MOISTURE BACK
INTO CWA WED AFTN AND WED NIGHT. MODELS HAVE BROUGHT SURFACE LOW
CLOSER TO AREA AND THUS MORE QPF IS BEING FCST THAN PREVIOUS MODEL
RUNS WHICH HAD A MORE EAST COAST SYSTEM. WILL BUMP POPS UP A BIT FOR
NOW. TRANSITION TO CAA APPEARS CERTAIN BEHIND SYSTEM LATE
WEDNESDAY NIGHT AND THURSDAY BUT HOW FAST AND IF ANY LINGERING
MOISTURE IS BIG QUESTION MARK. SHOULD SEE SOME LIGHT SNOW SHOWERS
AND PERHAPS SOME LIGHT ACCUM IF MODEL FCST IS ACCURATE. WILL GO
WITH A CHANGE OVER FOR NOW AND KEEP CHC POPS GOING INTO THURSDAY
WITH CAA AND PROBABLY LAKE ENHANCED SNOW SHOWERS. HAVE LOWERED
PREVIOUS FCST MAX TEMPS FOR THURSDAY BASED ON NEW MODELS. MAY SEE
TEMPS FALL DURING THE DAY INSTEAD OF RISE BUT WILL LET LATER FCST
HANDLE THE DETAILS. MORE SNOW SHOWERS POSSIBLE INTO THURSDAY NIGHT
AND FRIDAY BUT WILL ONLY GO SLIGHT CHC POPS FOR NOW UNTIL MORE
CERTAIN. TEMPS AGAIN AT OR BELOW GUID WITH COLDEST AIR IN PLACE.
NEW MODELS SHOWING NEXT SYSTEM BY SATURDAY BUT WILL WAIT TO SEE
FURTHER MODEL GUIDANCE BEFORE INSERTING ANY PRECIP FOR NOW.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
COLD FRONT WILL CROSS THE OHIO VALLEY...REACHING TAF SITES BETWEEN
1Z AND 3Z. AHEAD OF THIS...CIGS WILL PRIMARILY BE VFR UNTIL JUST
BEFORE FROPA WHERE MVFR CIGS COME IN WITH THE MOISTENING COLUMN.
RAIN WILL LIKELY HOLD OFF UNTIL AFTER 0Z. WIND WILL GUST FROM THE
SSW TO OVER 20KT IN THE WARM SECTOR THIS AFTERNOON...TURN W AND SW
IMMEDIATELY POST FRONTAL WITH FEWER GUSTS...AND THEN KICK BACK IN
WITH A STRONGER SUSTAINED 12-14+KT AND HIGHER GUSTS WHEN THEY TURN
NW IN THE COLD AIR ADVECTION. THIS COLD AIR WILL LIKELY INTRODUCE
A MORE SOLID OVC MVFR DECK. THERE IS A CHANCE FOR IFR CIGS BLO
1KFT IN THE COLD AIR...BUT THERE SHOULD BE ENOUGH MIXING THAT THEY
STAY MVFR OVERNIGHT TOMORROW.
THOUGHT THAT VSBY RESTRICTIONS IN RAIN TONIGHT WOULD BE LIMITED TO
ABOUT A 4 HOUR TIME FRAME AT MOST...MORE LIKELY 2 HOURS FOR
MAJORITY OF TAF SITES...PARTICULARLY SW OF CENTRAL OHIO. OTHERWISE
NO BIG CHANGES FROM PREV FCST.
OUTLOOK...MVFR CIGS TO LINGER INTO MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...SITES
NEAR TERM...SITES
SHORT TERM...SITES
LONG TERM...
AVIATION...FRANKS
