Flash Flooding in Indiana, May 25, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
547 AM EDT MON MAY 25 2009

.AVIATION...DISCUSSION FOR 251200Z TAF ISSUANCE.

SLOWLY EVOLVING UPR LOW ACRS NWRN AR WL CONT TO SEND DISTURBANCES
NWD ACRS CNTRL INDIANA THROUGH 18Z TUE. ALSO...SLOW MOVING CD FNT
ACRS SCNTRL IN WL RETURN N AS A WARM FNT TNGT AND TOMORROW. THESE WL
COMBINE WITH AN INCRSGLY MOIST AND UNSTABLE ATMS TO PROVIDE A FEW
ROUNDS OF TRWS TODAY THROUGH TOMORROW. CURRENT ACTIVITY ACRS SCNTRL
INDIANA WL CONT TO LIFT SLOWLY NWD THIS MRNG. LGT WAS INCRSG ON THE
LDS CHART...SO WENT WITH TEMPO TSRA GROUPS FOR ALL BUT LAF WHERE IT
WAS A BIT MORE STABLE AND UNCERTAIN THE NEXT SEVERAL HOURS.
OTHERWISE...WENT VCTS AND CBS BASED ON PROGGED INSTABILITY AND
SEVERAL MORE IMPULSES EXPECTED TO BE EJECTED N FM THE UPR LOW. MODEL
TIME SECS SEEM TO BE A BIT PESSIMISTIC REGARDING CIGS...SO WENT MORE
WITH PERSISTANCE AND VFR CIGS THROUGH TODAY AND THEN BECMG MVFR
TNGT. E WINDS SHOULD STAY UP ABV 5 KTS TNGT AND KEEP FOG FM FORMING.
ESE WINDS TO SHIFT TO THE S AFT 12Z TUE AT IND AS THE FNT LIFTS N.

&&

.PREV DISCUSSION...

FORECAST FOCUS IS ON CHANCES FOR RAIN INTO THURSDAY.

AT 06Z SFC AND UPPER LOWS WERE ACROSS ARKANSAS. QUASISTATIONARY
FRONT REMAINED ACROSS THE FORECAST AREA /FA/. A FEW LIGHT SHRA
WERE ACROSS THE WRN FA...WITH MOST PRECIP ACROSS SRN IL AND SERN
MO.

OVERALL...THE MODELS ARE IN FAIR AGREEMENT WITH THE SYNOPTIC
FEATURES. HOWEVER THE MODELS INITIALIZED POORLY WITH THEIR
PLACEMENT OF THE PRECIPITATION. THEY ARE ONCE AGAIN OVERDOING THE
EXTENT OF THE RAINFALL. THEY ALSO OVERDID PRECIP DEVELOPENT ON
SATURDAY.

WITH PLENTY OF UNCERTAINTY EXISTING ON HOW UPPER LOW WILL BE
ABSORBED INTO THE MAIN FLOW...WILL USE A BLEND OF MODELS FOR THE
MOST PART. HOWEVER WILL NOT NECESSARILY GO WITH MOS POPS DUE TO
THE MODEL/S RECENT POOR HANDLING OF RAINFALL.

UPPER LOW WILL CONTINUE TO DRIFT NW TODAY. WEAK ISENTROPIC LIFT
CONTINUES THROUGHOUT THE DAY. OTHER FORCING IS WEAK AND MAINLY
CONFINED TO THE SWRN FA CLOSER TO THE UPPER SYSTEM /AS CAN BE SEEN
IN QVECTOR CONVERGENCE PROGS/. EXPECT SOME INSTABILITY TO RETURN
TODAY WITH HEATING...AND THIS WILL INTERACT WITH THE OLD FRONT
ACROSS THE FA. PUTTING ALL OF THIS TOGETHER LEADS TO LIKELY POPS
ACROSS ROUGHLY THE SWRN 1/3 OF THE FA WITH CHC POPS ELSEWHERE.
GIVEN EXPECTED LOWER PRECIP COVERAGE WENT WITH THE WARMER END OF
MOS NUMBERS FOR HIGHS TODAY.

CONVECTION COVERAGE WILL DIMINISH WITH LOSS OF HEATING THIS
EVENING. HOWEVER...WITH THE OLD FRONT RETURNING NORTH AS A WARM
FRONT...FEEL THAT CHANCE POPS ARE WARRANTED IN THE OVERNIGHT
HOURS AS WELL. MAV/MET LOW TEMPS ARE SIMILAR AND LOOK REASONABLE
GIVEN EXPECTED CLOUD COVER AND A RELATIVELY HUMID AIRMASS.

FA WILL BE IN THE WARM SECTOR ON TUE. WITH NO SIGNIFICANT FORCING
PRESENT...FEEL THAT ONLY SCATTERED COVECTION WILL BE AROUND.
BETTER CHANCES FOR RAIN WILL ARRIVE ON WED WHEN SFC LOW AND COLD
FRONT MOVE INTO THE AREA...SO HAVE RAISED POPS INTO LIKELY
CATEGORY. ALSO ADDED SLIGHT CHANCE OF RAIN THU MORNING WITH UPPER
TROF MOVING ACROSS.

&&

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

&&

AVIATION...MK
PUBLIC...CS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
858 AM EDT MON MAY 25 2009

INZ021-028>031-035>049-052>057-061>065-069>072-261300-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-CLAY-OWEN-MORGAN-JOHNSON-
SHELBY-RUSH-GREENE-MONROE-BROWN-BARTHOLOMEW-DECATUR-MARTIN-
LAWRENCE-JACKSON-JENNINGS-
858 AM EDT MON MAY 25 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

RAIN AND THUNDERSTORMS WILL OCCUR TODAY. LOCALLY HEAVY RAINS WILL
OCCUR ESPECIALLY SOUTHWEST OF A LAFAYETTE TO NEW CASTLE LINE. SOME
AREAS COULD RECEIVE UP TO 2 INCHES OF RAIN TODAY. THIS MAY BE
SUFFICIENT TO PRODUCE FLOODING OF POOR DRAINAGE OR LOW LYING
AREAS ALONG WITH URBAN FLOODING DUE TO RUNOFF. CLOUD TO GROUND
LIGHTNING WILL BE A HAZARD IN ANY STORMS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THERE IS A CHANCE FOR THUNDERSTORMS TUESDAY AND WEDNESDAY. AT THIS
TIME...SEVERE WEATHER IS NOT EXPECTED. HOWEVER HEAVY DOWNPOURS AND
CLOUD TO GROUND LIGHTNING WILL BE A HAZARD IN ALL THUNDERSTORMS.

.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)

INZ051-060-067-068-261300-
VIGO-SULLIVAN-KNOX-DAVIESS-
858 AM EDT MON MAY 25 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

RAIN AND THUNDERSTORMS WILL OCCUR TODAY. LOCALLY HEAVY RAINS WILL
OCCUR. SOME AREAS COULD RECEIVE UP TO 2 INCHES OF RAIN TODAY.
THIS MAY BE SUFFICIENT TO PRODUCE FLOODING OF POOR DRAINAGE OR LOW
LYING AREAS ALONG WITH URBAN FLOODING DUE TO RUNOFF. CLOUD TO GROUND
LIGHTNING WILL BE A HAZARD IN ANY THUNDERSTORMS.

LOWLAND FLOODING WILL CONTINUE ALONG PORTIONS OF THE WABASH
RIVER. MODERATE FLOODING SHOULD END BY LATE TONIGHT. PLEASE SEE
THE LATEST HYDROLOGIC STATEMENTS FOR DETAILS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

LOWLAND FLOODING WILL CONTINUE ALONG PORTIONS OF THE LOWER WABASH
RIVER THROUGH THURSDAY. PLEASE SEE THE LATEST HYDROLOGIC
STATEMENTS FOR DETAILS.

THERE IS A CHANCE FOR THUNDERSTORMS TUESDAY AND WEDNESDAY. AT
THIS TIME...SEVERE WEATHER IS NOT EXPECTED. HOWEVER HEAVY
DOWNPOURS AND CLOUD TO GROUND LIGHTNING WILL BE A HAZARD IN ALL
THUNDERSTORMS.

.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)

CO