Areal Flood Warning 64, NWS Indianapolis, IN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
615 AM EST THU DEC 15 2011

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...

RAIN WITH CHANCES FOR THUNDERSTORMS AND POSSIBLY POCKETS OF HEAVY
RAIN ARE EXPECTED THROUGH THIS MORNING AHEAD OF A COLD FRONTAL
PASSAGE. COLDER AIR WILL FILTER IN BEHIND THIS FRONT ALONG WITH
SURFACE HIGH PRESSURE. THE NEXT PRECIPITATION PRODUCING SYSTEM COULD
ARRIVE AS EARLY AS SUNDAY NIGHT AND CHANCES WILL CONTINUE THROUGH
TUESDAY NIGHT. ASIDE FROM FRIDAY AND SATURDAY TEMPERATURES SHOULD BE
ABOVE NORMAL FOR THIS TIME OF YEAR.

&&

.NEAR TERM /TODAY/...

AS OF 08Z...WIDESPREAD RAINFALL NOW CONFINED TO THE SE HALF OF THE
FORECAST AREA WITH SCATTERED RAIN SHOWERS IN IT/S WAKE. CONVECTION
HAS REALLY DROPPED OFF IN THE LAST HOUR OR TWO BUT THE THREAT STILL
EXISTS FOR AN ISOLATED THUNDERSTORM...THOUGH MAINLY ACROSS THE SE AT
THIS TIME.

TREND FOR RAIN TO SLIDE OFF TO THE SE OF THE AREA WILL CONTINUE
THROUGH EARLY TODAY. AS THE FRONT MOVES THROUGH...TRIED TO DEPICT IN
THE GRIDS THIS NW TO SE DRYING TREND THROUGH 19Z THIS
AFTERNOON...WHEN THE MAJORITY OF THE FORECAST AREA IS EXPECTED TO BE
DRY AS THE COLD FRONT DROPS SOUTH. TEMPERATURE TREND IS FOR MUCH OF
THE FORECAST AREA (EXCEPT FOR THE SE CORNER) TO HIT THEIR HIGH
TEMP EARLY ON...AND THEN BEGIN DROPPING OFF THEREAFTER.

RAINFALL AMOUNTS SO FAR LOOK LIKE AN INCH TO UPWARDS AN INCH AND A
HALF WIDESPREAD FOR THE ENTIRE EVENT.

&&

.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...

HIGH PRESSURE RIDGE BUILDS BACK ACROSS THE FORECAST AREA FOR THE
SHORT TERM PERIOD. EXPECT A RETURN TO COOLER TEMPS AND DRY WEATHER.

SEE SIGNS IN MODEL TIME HEIGHTS AND SOUNDINGS THAT SKY COVER COULD
START TO DIMINISH BY EVENING...BUT THEN EXPECT SOME STRATUS TO
FILL BACK IN DURING THE OVERNIGHT WITH A FAIR AMOUNT OF LLVL
MOISTURE TRAPPED BENEATH AN INVERSION AND NORTHWESTERLY TO
NORTHERLY SURFACE FLOW. HAVE THUS BUMPED UP SKY COVER...NOT
ENTIRELY SURE HOW MUCH COVERAGE WE WILL HAVE BUT SHOULD AT LEAST
BE ENOUGH FOR PARTLY CLOUDY...IF NOT EVEN MOSTLY CLOUDY OVERNIGHT.

RAISED THE SKY COVER ON FRIDAY AS WELL FOR THE SAME REASON FROM
MOSTLY SUNNY TO PARTLY CLOUDY. FOR FRIDAY NIGHT AND SATURDAY SHOULD
SEE MOSTLY CLEAR SKIES AND A GUIDANCE BLEND CAPTURED EXPECTED
TEMPERATURES WELL GIVEN THE FORECAST 850 MB TEMPERATURES.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...

ONCE AGAIN THE STORY IS SIGNIFICANT RUN TO RUN AND MODEL TO MODEL
INCONSISTENCIES REGARDING THE HANDLING OF A CUTOFF LOW ACROSS THE
SOUTHWEST EARLY IN THE LONG TERM...WHICH TRACKS TO THE EAST AND
THEN NORTHEAST THROUGH THE AREA LATE SUNDAY THROUGH LATE TUESDAY.
GIVEN THESE CONTINUED INCONSISTENCIES...SEE LITTLE REASON TO
DEVIATE FROM INITIALIZATION/ENSEMBLE APPROACH.

GENERAL TREND APPEARS TO BE TOWARD A SLOWER AND MORE SOUTHERLY
TRACK. WHILE TEMP PROFILES STILL APPEAR TO FAVOR RAIN...CONTINUED
TRENDS TOWARD THE SOUTH COULD INTRODUCE HIGHER CHANCES OF SNOW.

TEMPS LOOK REASONABLE THROUGHOUT.

&&

.AVIATION /DISCUSSION FOR THE 15/12Z TAFS/...

VERY GRADUAL IMPROVEMENT EXPECTED IN CONDITIONS THROUGH THE TAF
PERIOD. MOST SITES WILL BEGIN NEAR HIGH END OF IFR...BECOMING MVFR
BEHIND THE APPROACHING COLD FRONT...THEN POSSIBLY BECOMING VFR AS
EARLY AS THIS EVENING OR LATE TONIGHT.

MAINLY HIGH END IFR CEILINGS AHEAD OF THE APPROACHING COLD FRONT TO
THE WEST. BRIEF FORAYS INTO LOW END MVFR WILL BE POSSIBLE...BUT IFR
SHOULD PREVAIL. WINDS WILL REMAIN STRONG AND GUSTY FROM THE
SOUTHWEST UNTIL FRONTAL PASSAGE.

HAVE TIMED FRONTAL PASSAGE AS CLOSELY AS POSSIBLE...AROUND 14Z
LAF...1530Z HUF...1630Z IND AND 1745Z BMG. THE FRONT WILL BE
ACCOMPANIED BY BRIEF MODERATE RAIN AND PERHAPS SOME VERY QUICK LOW
MVFR OR IFR VISIBILITIES BEFORE CONDITIONS QUICKLY IMPROVE TO LOW
END MVFR BEHIND THE FRONT.

WINDS WILL SHIFT QUICKLY FROM 210-230 DEGREES AHEAD OF THE FRONT TO
AROUND 280 DEGREES BEHIND IT...AND MAINTAIN ROUGHLY THIS HEADING OR
SLIGHTLY TO THE NORTHWEST THROUGH THE REMAINDER OF THE PERIOD. OBS
AND MOMENTUM TRANSFER PROGS SUGGEST GUSTS CONTINUING IN THE MID TO
UPPER 20KT RANGE THROUGH THE DAY.

AM SUSPICIOUS OF GUIDANCE DESIRE TO CLEAR SKIES OUT THIS EVENING FOR
THREE REASONS...STRATUS TO WEST IS VERY EXPANSIVE AND GUIDANCE OFTEN
CLEARS STRATUS 12 TO 24 HOURS TOO QUICKLY OR MORE...TIME HEIGHT
SECTIONS SHOW LINGERING LOW LEVEL MOISTURE WELL BEYOND THIS
EVENING...AND APPRECIABLE LOW LEVEL WARM ADVECTION DOES NOT BEGIN
UNTIL FRIDAY NIGHT OR SATURDAY. FOR NOW...HAVE DELAYED LIFTING OF
STRATUS ABOUT 6-12 HOURS BEYOND WHAT IS DEPICTED BY GUIDANCE...AND
HAVE KEPT SKY BROKEN THROUGHOUT. LATER PACKAGES WILL NEED TO
DETERMINE WHETHER TO EXTEND THIS OR NOT. COULD SEE SOME DIURNAL
REDEVELOPMENT OF LOW STRATUS LATE IN THE TAF PERIOD...BUT THIS IS
LOW CONFIDENCE FOR NOW.

&&

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

&&

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...NIELD

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
536 AM EST THU DEC 15 2011

INZ030-031-036>042-045>049-052>057-061>065-069>072-161045-
CLINTON-HOWARD-MONTGOMERY-BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-
RANDOLPH-PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-CLAY-OWEN-MORGAN-
JOHNSON-SHELBY-RUSH-GREENE-MONROE-BROWN-BARTHOLOMEW-DECATUR-
MARTIN-LAWRENCE-JACKSON-JENNINGS-
536 AM EST THU DEC 15 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

OUTLOOK: RAIN SHOWERS WILL COME TO AN END BY THIS AFTERNOON.

HAZARDS: LOCALIZED FLOODING IS POSSIBLE.

TIMING: LOCALIZED FLOODING IS POSSIBLE UNTIL NOON.

DISCUSSION: A COLD FRONT WILL MOVE ACROSS CENTRAL INDIANA
EARLY TODAY. COLDER AIR WILL FILTER IN BEHIND THIS FRONT ALONG WITH
SURFACE HIGH PRESSURE.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

OUTLOOK: COLDER AND DRIER CONDITIONS EXPECTED FOR THE REST OF THE
WEEK. A RETURN OF PRECIPITATION IS POSSIBLE EARLY NEXT WEEK.

DISCUSSION: HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH
THE WEEKEND. A LOW PRESSURE SYSTEM MAY APPROACH THE AREA FROM THE
SOUTHWEST EARLY NEXT WEEK. THERE IS A CHANCE OF A RAIN OR SNOW MIX
WHICH COULD IMPACT CENTRAL INDIANA TUESDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

INZ021-028-029-035-043-044-051-060-067-068-161045-
CARROLL-WARREN-TIPPECANOE-FOUNTAIN-VERMILLION-PARKE-VIGO-SULLIVAN-
KNOX-DAVIESS-
536 AM EST THU DEC 15 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

OUTLOOK: RIVER FLOOD WARNINGS REMAIN IN EFFECT. RAIN SHOWERS WILL
COME TO AN END EARLY TODAY.

HAZARDS: RIVER FLOODING WILL CONTINUE AT MANY LOCATIONS ALONG THE
WABASH...WHITE...EAST FORK WHITE AND MUSCATATUCK RIVERS.

TIMING: FLOODING ONGOING.

DISCUSSION: A COLD FRONT WILL MOVE ACROSS CENTRAL INDIANA
EARLY TODAY. COLDER AIR WILL FILTER IN BEHIND THIS FRONT ALONG WITH
SURFACE HIGH PRESSURE.

RIVER FLOODING CONTINUES ACROSS AREA RIVERS DUE TO PRIOR RAINFALL.
PLEASE SEE THE LATEST HYDROLOGIC STATEMENTS FOR MORE DETAILED
RIVER FLOODING INFORMATION.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

OUTLOOK: AREA RIVER LEVELS CONTINUE TO FALL WITH FLOODING EXPECTED
TO COME TO AN END AT MOST LOCATIONS BY LATE IN THE WEEK. COLDER AND
DRIER CONDITIONS EXPECTED FOR THE REST OF THE WEEK. A RETURN TO
RAINFALL IS POSSIBLE EARLY NEXT WEEK.

DISCUSSION: HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH
THE WEEKEND. A LOW PRESSURE SYSTEM MAY APPROACH THE AREA FROM THE
SOUTHWEST EARLY NEXT WEEK. THERE IS A CHANCE OF A RAIN OR SNOW MIX
WHICH COULD IMPACT CENTRAL INDIANA TUESDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

SMF