FXUS61 KILN 292119
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
419 PM EST SUN NOV 29 2009

.SYNOPSIS...
A COLD FRONT WILL PUSH ACROSS THE REGION TONIGHT BRINGING RAIN
SHOWERS. HIGH PRESSURE WILL THEN BUILD INTO THE AREA LATE MONDAY
INTO TUESDAY....BEFORE A MORE AGGRESSIVE FRONTAL SYSTEM APPROACHES
BY MID WEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
TIMING BETWEEN SREF AND GFS SIMILAR WITH THE FROPA OVERNIGHT...
WITH GFS MORE AGRESSIVE WITH THE LIFT AND MORE WIDESPREAD WITH THE
PRECIPITATION THIS EVENING AND OVERNIGHT...LIKELY DUE TO A GREATER
ENHANCEMENT OF THE LLJ AND LL CONVERGENCE OVERNIGHT. THOUGHT IS THAT
NAM IS TOO QUICK AND NOT AGGRESSIVE ENOUGH WITH THE LIFT. WHILE
POST FRONTAL PRECIP EXPECTED...SHOULD BE A PRETTY SHARP DROP OFF
AS DRY AIR EVENTUALLY WORKS IN. PRECIP SHOULD END IN ALL BUT THE
FAR SOUTH AND EAST BY 12Z...WITH FRONT WELL TO THE EAST BY THAT
TIME.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
HAVE TAKEN HIGH TEMPS DOWN A LITTLE FOR MONDAY...AS NW FLOW WORKS
IN. AGAIN STUCK CLOSER TO MAV MOS RATHER THAN NAM NUMBERS. A
QUICKLY MOVING S/WV PUSHES THROUGH MON NIGHT ACROSS THE LOWER
GREAT LAKES...SO HAVE CONTINUED THE SLIGHT CHANCE FOR SHSN IN THE
FAR NORTH. 

RIDGING THEN BUILDS IN FOR TUE..BUT AS AGGRESSIVE SPLIT FLOW
PATTERN DEVELOPS IN THE SOUTHERN PLAINS AND NORTHERN
PLAINS...HIGH WILL PUSH PRETTY QUICKLY EAST AHEAD OF THE SOUTHERN
LOW. 

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN SPLIT FLOW PATTERN SOUTHERN STREAM UPPER LOW OVER TEXAS TO LIFT 
NE INTO THE LOWER OHIO VALLEY ON WEDNESDAY AND THEN LIFT INTO THE
OHIO VALLEY WED NIGHT AND MERGE WITH FLOW AHD OF A DIGGING LONG WAVE
TROF. OPERATIONAL NUMERICAL MODEL SOLNS AND SREF MEAN TRENDING A LTL
SLOWER WITH THIS SYSTEM. SO THEREFORE HAVE HELD OFF RAIN UNTIL WED 
AFTN WITH PRECIP SPREADING IN FROM THE SOUTH. WITH ASSOCIATED SFC 
WAVE TRACKING INTO THE UPR OHIO VALLEY WED NIGHT HAVE INCREASED POPS
TO LKLY ACRS THE SOUTHEAST. ALSO...AS COLDER AIR FUNNELS INTO THE 
REGION BEHIND THE LOW EXPECT A CHANGE OVER TO SNOW. WITH MOISTURE 
LINGERING AND DIGGING UPR TROF...THIS MAY BE THE FIRST ACCUMULATING 
SNOW OF THE SEASON IN MANY LOCATIONS. 

DEEP UPPER LEVEL TROF TO SETTLE INTO THE GREAT LAKES ON THURSDAY 
WITH CONSIDERABLY COLDER TEMPS EXPECTED. SNOW SHOWERS TO CONTINUE 
WITH LAKE ENHANCED SNOW SHOWERS LIKELY LIKELY ACRS W CENTRAL OHIO
WITH FAVORABLE FETCH OFF LAKE MI. WL END ANY MENTION OF SNOW SHOWERS
FRIDAY AS SFC RIDGING BUILDS INTO THE OHIO VLY. 

SOLNS SHOW A LARGE DIVERGENCE NEXT WEEKEND WITH ECMWF MAINTAINING THE
UPPER LOW OVER THE GREAT LAKES WHILE THE GFS IS MORE PROGRESSIVE. WL 
FOLLOW SOLN CLOSER TO ECMWF WITH CONTD COLD TEMPERATURE BUT DRY 
CONDITIONS WITH SNOW SHOWERS EXPECTED TO REMAIN NORTH OF ILN/S FA. 

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MID CLOUDS ARE PUSHING INTO THE FORECAST AREA AS OF THIS
WRITING...WITH LOW VFR CLOUDS BEGINNING TO GET CLOSE AS WELL.
CLOUDS WILL INCREASE IN THE FIRST 6 HOURS OF THE TAF PERIOD...WITH
SOUTHWEST WINDS OCCASIONALLY GUSTING UP TO AROUND 20 KNOTS.

COLD FRONT WILL PUSH IN OVERNIGHT...LEADING TO A GOOD SHOT AT RAIN
SHOWERS AT ALL TAF LOCATIONS. HAVE TRIED TO TIME OUT THE WORST OF
IT IN A PERIOD FROM ROUGHLY 03Z-09Z FROM WEST TO EAST. NOT LOOKING
AT TERRIBLY HEAVY PRECIPITATION...BUT ENOUGH INCREASED MOISTURE TO
IMPACT THE TAFS. FLIGHT CATEGORY RESTRICTIONS WILL BE MORE LIKELY
TO BE CEILING- BASED...AND HAVE INCLUDED SOME GROUPS IN THE LOW
RANGE OF MVFR. A PERIOD OF IFR IS NOT OUT OF THE QUESTION...BUT
THIS CAN BE REFINED IN LATER FORECASTS.

TOWARD MORNING TOMORROW...LOOKING FOR THINGS TO GRADUALLY SCATTER
OUT AS THE MOISTURE WORKS EAST AWAY FROM THE REGION. EXPECTING VFR
CONDITIONS AGAIN WITHIN A COUPLE HOURS AFTER SUNRISE.

OUTLOOK...MVFR/IFR CONDITIONS POSSIBLE WITH RAIN AND SNOW SHOWERS
WEDNESDAY NIGHT INTO THURSDAY.

&&

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

&&

$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...JDR
LONG TERM...AR
AVIATION...HATZOS