Flash Flood and Damaging Wind in Indiana, June 25 to 26, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
200 PM EDT THU JUN 25 2009

.DISCUSSION...FCST FOCUS IS ON STORM CHCS TONIGHT...THEN ON TEMPS.

WAVE VAPOR IMAGERY INDICATES A VIGOROUS UPPER WAVE ACROSS SOUTHERN
ONTARIO NEAR THE NORTHERN SHORE OF LAKE SUPERIOR. ANOTHER WEAKER
WAVE WAS LOCATED ACROSS MO. AT THE SFC...A VERY DIFFUSE PATTERN
REMAINS IN PLACE WITH A WEAK COLD FRONT EXTENDING FROM WI INTO IA
WHILE OTHER WEAK OUTFLOW AND LAKE BOUNDARIES WERE ACTING TO FOCUS
CONVECTION THIS AFTERNOON. ONE SUCH BOUNDARY WAS ACROSS CENTRAL OH
WHILE CONVECTION WAS DEVELOPING ACROSS SOUTHERN LOWER MI. AIR TEMPS
ARE AGAIN RISING TO AROUND 90 WHILE DEWPOINTS REMAIN AROUND 70 TODAY.

I WILL LEAN TOWARD OBS/VIS SAT TRENDS FOR THIS EVENINGS FCST. ALL IN
ALL I WILL USE A BLEND OF NAM/MAV MOS TEMPS THROUGH SAT. THE
EXTENDED IS WEIGHTED MORE TOWARD THE GFS ENSEMBLE WITH A STRONGER
UPPER LOW ACROSS THE NE.

THIS EVENING AND TONIGHT...A VERY UNSTABLE AIRMASS WILL REMAIN IN
PLACE AS WEAK SFC CONVERGENT AXES ACT TO TRIGGER THUNDERSTORMS. BEST
ESTIMATE AT THIS TIME IS THAT STORMS WILL CONTINUE TO DEVELOP NEAR
THE LAKE ACROSS NE IL INTO LOWER MI AND NORTHERN IN. THESE STORMS
SHOULD MOVE SE AND COULD CLIP NE PARTS OF THE CWA TOWARD 22Z OR 00Z.
OTHER STORMS ACROSS EASTERN IA COULD ALSO CONGEAL INTO A COMPLEX AND
HEAD SE ALTHOUGH THIS WOULD TAKE UNTIL WELL AFTER 00Z IF THIS
SCENARIO UNFOLDS. IN A NUTSHELL THIS IS A LOW CONFIDENCE FCST...THE
BEST FORCING AND TRIGGERS APPEAR TO BE NORTH OF THE CWA AND WITH
STORM MOTION AT 320/20KTS IT SUGGESTS THAT OUR NORTHERN COUNTIES
HAVE THE BEST SHOT AT STORMS THIS EVENING INTO TONIGHT. CANNOT RULE
OUT SCT STORMS ELSEWHERE AND WE WILL WORD THE FCST AS SUCH. GIVEN
THE CAPE AND MODEST SHEAR LOWER END ORGANIZED MULTICELLS WOULD BE
THE MODE OF CHOICE WITH DOWNBURST/DAMAGING WINDS THE MAIN THREAT.
MOS LOWS LOOK REASONABLE AND WILL USE A BLEND.

FRI...THE WEAK BOUNDARY WILL SLIDE INTO SOUTHERN IN WHILE THE
THERMAL PROFILE COOLS ONLY SLIGHTLY AS COMPARED TO TODAY. THIS
SHOULD YIELD HIGHS AGAIN NEAR 90 WITH PERHAPS SOME RELIEF IN THE
FORM OF SLIGHTLY LOWER DEWPOINTS BY LATE AFTERNOON. MOS TEMPS ARE IN
REASONABLE AGREEMENT AND LOOKING AT 850MB TEMPS FEEL THAT A BLEND IS
BEST.

SAT...SHORTWAVE RIDGE WILL MOVE ACROSS THE AREA AS THE NEXT UPPER
TROUGH MOVES INTO THE PLAINS. DAYTIME HIGHS SHOULD AGAIN REACH OR
EXCEED 90 AS THE LOW LEVEL THERMAL RIDGE IS DRAGGED NE ACROSS THE
AREA. BASED ON 850MB TEMPS AND THICKNESSES FEEL THAT THE CURRENT
FCST TEMPS ARE BETTER THAN THE MOS GUIDANCE WHICH IS COOLER DUE TO
WHAT APPEARS TO BE MORE CLD COVER. WE WILL KEEP THE FCST DRY FOR SAT
AT THIS TIME.

SAT NIGHT-SUN...A STRONG UPPER WAVE AND ASSOCIATED SFC COLD FRONT
WILL SWEEP THROUGH THE AREA. LOOK FOR SCT STORMS ALONG THE FRONT SAT
NIGHT WITH COOLER AND LESS HUMID CONDS SUN. THE COOLER AND MORE
COMFORTABLE CONDS SHOULD PREVAIL INTO EARLY NEXT WEEK WITH DRY CONDS
THROUGH AT LEAST WEDS.

&&

.AVIATION...

VERY WEAK COLD FRONT SLOLY PASSING INDIANA FROM NW LATE TDY INTO
FRIDAY. SCT TSRA IN WARM AIR AHEAD OF FNT INRCSG WITH FROPA...THEN
DECREASING LATE TNGT. BRF CIGS 3 THSD FT AND VSBYS 1 MI IN TSTM.
OVER MOST OF AREA SCT-BKN050 P6SM...XCP AREAS VSBY 3-5 MI IN BR ARND
SUNRISE. WINDS W LESS THAN 10 MPH TDY...LGT AND VRBL TNGT WITH
FROPA...AND NW LESS THAN 10 MPH FRI.

&&

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

&&

AVIATION...KWIATKOWSKI
PUBLIC...CO

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
827 AM EDT THU JUN 25 2009

INZ021-028>031-035>049-051>057-060>065-067>072-261230-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-VIGO-CLAY-OWEN-MORGAN-
JOHNSON-SHELBY-RUSH-SULLIVAN-GREENE-MONROE-BROWN-BARTHOLOMEW-
DECATUR-KNOX-DAVIESS-MARTIN-LAWRENCE-JACKSON-JENNINGS-
827 AM EDT THU JUN 25 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF A COLD
FRONT TODAY. THE STORMS SHOULD DEVELOP AFTER THE NOON HOUR ACROSS
PARTS OF CENTRAL AND NORTHERN ILLINOIS INTO NORTHERN INDIANA AND
LOWER MICHIGAN. THE STORMS WILL MOVE SOUTHEAST AND COULD IMPACT
PARTS OF CENTRAL INDIANA AFTER 2 PM EDT THIS AFTERNOON. THE MAIN
THREAT WILL BE DAMAGING WINDS AND IT APPEARS THAT THE THREAT FOR
DAMAGING WINDS WILL BE GREATEST NORTH OF INTERSTATE 70.

AT THIS TIME THE RISK FOR SEVERE WEATHER SHOULD OCCUR BETWEEN 2 PM
AND 10 PM EDT TODAY.

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

THUNDERSTORM ACTIVITY IS POSSIBLE SATURDAY NIGHT. IT IS TOO EARLY
TO DETERMINE WHETHER SEVERE WEATHER WILL BE POSSIBLE SATURDAY
NIGHT. STAY TUNED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE THIS AFTERNOON.

&&

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1225 PM EDT THU JUN 25 2009

INZ021-028>031-035>049-051>057-060>065-067>072-252000-
BARTHOLOMEW-BOONE-BROWN-CARROLL-CLAY-CLINTON-DAVIESS-DECATUR-
DELAWARE-FOUNTAIN-GREENE-HAMILTON-HANCOCK-HENDRICKS-HENRY-HOWARD-
JACKSON-JENNINGS-JOHNSON-KNOX-LAWRENCE-MADISON-MARION-MARTIN-MONROE-
MONTGOMERY-MORGAN-OWEN-PARKE-PUTNAM-RANDOLPH-RUSH-SHELBY-SULLIVAN-
TIPPECANOE-TIPTON-VERMILLION-VIGO-WARREN-
1225 PM EDT THU JUN 25 2009

...HOT AND HUMID AGAIN THIS AFTERNOON...

HIGHS IN THE LOWER 90S AND DEWPOINTS NEAR 70 WILL PRODUCE HEAT
INDEXES APPROACHING 100 TODAY. BE CAREFUL TO AVOID OVER EXERTION AND
DRINK PLENTY OF FLUIDS.

BELIEVE IT OR NOT...DUE TO A FEW EXTRA CLOUDS TODAY WILL
ACTUALLY BE A DEGREE OR TWO COOLER THAN YESTERDAY WAS.

KWIATKOWSKI