000
FXUS63 KIND 240438
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1130 PM EST MON NOV 23 2009

.AVIATION DISCUSSION...FOR THE 06Z TAFS
MAIN PROBLEM FOR AVIATION WILL BE MVFR CONDITIONS OVER CENTRAL
INDIANA AND IFR IN THE NORTH. A STATIONARY FRONT EXTENDED ACROSS
NORTHERN INDIANA. THIS FRONT WILL MOVE LITTLE THROUGH LATE MORNING
THEN BEGIN TO MOVE NORTH. VERY MOIST AIR WAS MOVING UP FROM THE
SOUTH. MIXING AFTER SUNRISE WILL BRING CONDITIONS INTO VFR RANGE BY
17Z. A COLD FRONT WILL MOVE INTO EASTERN ILLINOIS AROUND 03Z.
SHOWERS WILL DEVELOP AHEAD OF THE FRONT. CONDITIONS WILL DECREASE TO
MVFR WITH THE SHOWERS.

&&

.UPDATE...
CLOUDS ARE CONTINUING TO FILTER INTO SOUTHERN CWA. SO...BUMPED
TONIGHT/S LOWS UP A FEW DEGREES OVER SOUTHWEST PORTIONS OF CWA.
FURTHER NORTH...TRIMMED SKY COVER BACK OVER NORTHERN COUNTIES FOR
THE NEXT FEW HOURS. LEFT PATCHY FOG ACROSS ENTIRE CWA FOR NOW. FOG
HAS ALREADY FORMED OVER NORTHERN HALF OF CWA...BUT STILL
QUESTIONABLE ACROSS SOUTHERN HALF. FEEL INCREASED CLOUD COVER WILL
HINDER DEVELOPMENT...BUT WILL HAVE TO BE MONITORED.

&&


.PREV DISCUSSION... /ISSUED 615 PM EST MON NOV 23 2009/

AVIATION DISCUSSION...FOR THE 06Z TAFS
MAIN CONCERN FOR AVIATION WILL BE DECREASING CONDITIONS TONIGHT. A
WARM FRONT EXTENDED ACROSS CENTRAL INDIANA. THE FRONT EXTENDS TO A
LOW IN KANSAS. VERY MOIST AIR WAS FLOWING UP FROM THE GULF INTO
INDIANA. AS THE FRONT MOVES INTO NORTHERN INDIANA TONIGHT THIS MOIST
AIR WILL MOVE IN. CONDITIONS WILL DECREASE TO IFR LEVELS FROM
04Z-06Z AT IND...HUF AND BMG THEN AROUND 08Z AT LAF. THESE
CONDITIONS WILL CONTINUE UNTIL 16Z WHEN THERE WILL BE ENOUGH MIXING
TO BRING CONDITIONS INTO MVFR RANGE. THE FRONT WILL BECOMING
STATIONARY OVER NORTHERN INDIANA ON TUESDAY AS THE LOW MOVES INTO
NORTHERN ILLINOIS. WITH CONTINUED MIXING AND HEATING DURING THE DAY
CONDITIONS WILL IMPROVE TO VFR. IN THE EXTENDED PORTION OF THE IND
TAF SCATTERED SHOWERS WITH MVFR CONDITIONS WILL MOVE IN AFTER 00Z.

DISCUSSION...

FORECAST FOCUS IS ON CHANCES FOR PRECIPITATION THROUGH THE WORK WEEK.

AT 18Z A WEAKENING UPPER WAVE WAS NEAR THE OHIO RIVER AND WAS MOVING
NORTHEAST. ISOLATED SHOWERS AND SPRINKLES WERE DECREASING IN
COVERAGE ACROSS SOUTHERN INDIANA. EXTENSIVE CLOUD COVER STRETCHED
FROM SOUTHERN INDIANA TO NEAR THE GULF COAST.

STILL SOME TIMING DIFFERENCES WITH THE MODELS FOR THE FIRST AREA OF
RAIN IMPACTING THE AREA TUESDAY EVENING...WITH GFS CONTINUING TO BE
FASTER AND NAM SLOWER. CANADIAN GEM IS IN BETWEEN AND LOOKS TO BE A
GOOD COMPROMISE. FOR THANKSGIVING...GFS STANDS ALONE IN A SLOWER AND
FARTHER SOUTH UPPER LOW. WILL GO WITH CONSENSUS OF
NAM/CANADIAN/UKMET/ECMWF WITH THE LOW CLOSER TO SOUTHERN END OF LAKE
MICHIGAN.

SOUTHERLY FLOW TONIGHT SHOULD BRING THE AFOREMENTIONED CLOUD DECK
NORTH ACROSS THE AREA. WEAK ISENTROPIC UPGLIDE WILL AID IN CLOUD
DEVELOPMENT...AND COULD POSSIBLY CREATE SOME DRIZZLE. NOT CONFIDENT
ENOUGH FOR DRIZZLE TO PUT IN GRIDS AT THE MOMENT THOUGH. LOW LEVEL
MOISTURE WILL LEAD TO SOME FOG DEVELOPMENT OVERNIGHT...BUT CLOUD
COVER SHOULD HELP KEEP IT FROM GETTING DENSE. WILL KEEP PATCHY FOG
IN THE FORECAST. WITH THE CLOUDS AROUND...TRENDED TOWARD THE WARMER
MAV FOR LOWS.

ON TUESDAY EXPECT CLOUDS TO HANG AROUND DURING THE
MORNING...POSSIBLY BREAKING UP SOME BY EARLY AFTERNOON. HOWEVER...BY
THEN MID AND HIGH CLOUDS AHEAD OF AN APPROACHING COLD FRONT WILL BE
MOVING IN. THUS MOSTLY CLOUDY LOOKS BEST. CURRENT PROJECTED TIMING
OF THE FRONT GIVES CHANCE POPS AFTER 18Z ACROSS THE WESTERN 2/3 OF
THE AREA. FOR THE MOST PART MAV/MET ARE SIMILAR AND THUS USED A
BLEND. DID HOWEVER GO A LITTLE COOLER IN SOME AREAS DUE TO EXPECTED
CLOUD COVER.

COLD FRONT MOVES ACROSS THE AREA TUESDAY EVENING AS FIRST UPPER LOW
HEADS INTO NORTHERN ILLINOIS. QVECTOR FORECASTS INDICATE BEST
FORCING WILL BE ACROSS THE NORTHERN PART OF THE AREA...AS WOULD BE
EXPECTED CLOSER TO THE UPPER LOW. WILL GO LIKELY POPS ACROSS THE
NORTHERN HALF OF THE AREA. WENT HIGHEST DURING THE EVENING AS MOST
MODELS WEAKEN THE FORCING OVERNIGHT.

ON WEDNESDAY THE AREA WILL BE IN BETWEEN UPPER LOWS AND IN THE FIRST
SHOT OF COLDER AIR. THERE COULD BE SOME RAIN AROUND IN THE CYCLONIC
FLOW...BUT WITH NO REAL ORGANIZED FORCING KEPT POPS AT OR BELOW 30
PERCENT. THE PUSH OF EVEN COLDER AIR WILL ARRIVE WEDNESDAY NIGHT
INTO THANKSGIVING. AT THE MOMENT IT APPEARS THAT ANY MIXING WITH
SNOW WILL HOLD OFF UNTIL LATE WEDNESDAY NIGHT. BEST FORCING WITH THE
UPPER LOW IS ON THURSDAY AFTERNOON...AND SCATTERED RAIN/SNOW SHOWERS
STILL LOOK TO OCCUR. SYSTEM SLOWLY EXITS INTO FRIDAY...AND COLD
NORTHWEST FLOW SHOULD GENERATE A FEW SNOW SHOWERS ACROSS EASTERN
AREAS ON FRIDAY. NO ACCUMULATION IS EXPECTED.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...CS
AVIATION...SH
UPDATE...TDUD