Severe Thunderstorm Warning 300, NWS Indianapolis, IN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
700 PM EDT SUN AUG 27 2006

.AVIATION...DISCUSSION FOR 280000Z TAF ISSUANCE. CONVECTIVE THREAT
TEMPO DIMINISHING ACRS THE TERMINALS AS MOST THE ACTVTY IS EITHER
DISSIPATING LOCALLY OR ORGANIZING FARTHER TO THE S. HOWEVER...THINK
CONVECTIVE THREAT WL BE INCREASING AGAIN LTR THIS EVEN/TONIGHT FM
THE SW AS 850MB JET DVLPS AND INTERACTS WITH A FRONTAL BOUNDARY.
MODELS SUGGEST BEST LIFT SHOULD BE MOVG OVR THE TERMINALS FM
280300Z-281100Z...SO XPCTG BEST COVERAGE OF CONVECTION IN THAT TIME
FRAME. GIVEN THE HI DEWPTS/P-WAT VALUES...IFR CONDS PROBABLE IN THE
HEAVIER SHOWERS. ALSO...DUE TO XPCTD PCPN...FARILY WIDESPREAD CIGS
008-015 AGL SHOULD DVLP AFT 280600Z...ESPECIALLY N OF SFC BOUNDARY.

&&

.PREV DISCUSSION...LATEST SFC MAP SHOWS A WEAK LOW ACROSS NE OHIO
WITH A COLD FRONT EXTENDING ACROSS CENTRAL INDIANA INTO MISSOURI.
TSRA ARE DEVELOPING AHEAD OF THIS FRONT SOUTH OF I-70.  PRECIPITABLE
H2O VALUES OF 1.75 TO 2 INCHES REMAIN ACROSS THE REGION. MAIN UPPER
WAVE IS STILL LAGGING BACK ACROSS THE CENTRAL PLAINS. LATEST
PROFILER NETWORK SHOWS 5-15KT WESTERLY 850MB WINDS.

OVERALL MODEL FEATURES SHOWING MINOR DIFFERENCES IN THE PLACEMENT
AND TIMING OF PRECIP TONIGHT/MONDAY. NGM IS THE ONLY MODEL THAT
FOCUSES BULK OF PRECIP SOUTH OF THE REGION. BASED UPON THE POSITION
OF THE 850-600MB FRONTOGENESIS LOCATION TONIGHT-MON I WILL FOLLOW
THE MORE NORTHERLY ETA/GFS PRECIP FCST WHILE ACKNOWLEDGING THE
SPURIOUS GFS QPF BULLSEYE.

MAIN FORECAST ISSUE WL BE EXTENT OF RAIN OVR NEXT 24-36 HOURS.

THIS EVENING AND OVERNIGHT...EXPECT AN INCREASE IN PRECIP WITH
DIURNAL HEATING ACROSS THE SOUTHERN HALF OF THE CWA. WET MICROBURSTS
WOULD BE THE MAIN THREAT WITH ANY STORMS SINCE 6KM WIND SHEAR
REMAINS LESS THAN 30KTS. I HAVE THE HIGHEST PRECIP CHCS ACROSS THE
SOUTH THIS EVENING. BY LATER TONIGHT...850MB WINDS WILL TURN SSW
WITH OVERRUNNING/ISENTROPIC LIFT OVER THE 850MB FRONT. 850-600MB
FRONTOGENESIS ALSO INCREASES AFTER MIDNIGHT MAINLY ACROSS THE NW
HALF OF THE STATE INTO THE NORTHERN HALF OF IL. IN A NUTSHELL, I
WILL KEEP LIKELY AT ALL LOCATIONS AFTER MIDNIGHT WITH LOCALLY HEAVY
RAINS POSSIBLE.

MONDAY...ETA/GFS AND NGM ALL SHOW THE BULK OF LIFT MOVING ACROSS THE
AREA. THIS SHOULD LEAD TO OCCASIONAL TSRA WITH MORE HEAVY RAINS
POSSIBLE. I HAVE RAISED PRECIP CHCS TO MIRROR MOS AVGS WHICH ARE IN
THE LIKELY/CATEGORICAL RANGE. GIVEN THIS, I WILL KEEP FCST HIGHS ON
THE COOL SIDE OF GUIDANCE MOS.

BASED UPON THE BLOCKY NATURE OF THE HEMISPHERIC FLOW PER HPC
DISCUSSION I WILL OPT FOR THE SLOWER ETA SOLUTION OF LINGERING
PRECIP CHCS INTO TUES. THE UPPER LOW SHOULD WEAKEN AS IT MOVES
ACROSS THE REGION TUES-WEDS AS IT INTERACTS WITH THE TROPICAL
SYSTEM. HOWEVER, IT APPEARS THAT THE SFC FRONT AND 850MB FRONT
SHOULD BE SE OF THE REGION BY TUES NIGHT. THE ETA DOES DRAG A
DEFORMATION ZONE ACROSS THE AREA TUES AND I WILL CONTINUE THE
GENERAL 40 POPS. NO CHANGES WILL BE MADE TO THE EXTENDED WITH A HIGH
AMPLITUDE/BLOCKY LONGWAVE PATTERN TO PERSIST. DRY WX WITH NEAR
SEASONAL TEMPS APPEAR IN STORE LATER THIS WEEK.

&&

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

&&

AVIATION...JAS
PUBLIC...CO

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
344 PM EDT SUN AUG 27 2006

INZ021-028>031-035>049-051>057-281945-
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-
344 PM EDT SUN AUG 27 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA FOR THOSE
AREAS ALONG AND NORTH OF INTERSTATE 70.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD LATER
TONIGHT. THE MAIN THREAT WITH THE STORMS WILL BE FOR LOCALLY HEAVY
RAINS AND FLOODING. CLOUD TO GROUND LIGHTNING WILL ALSO BE A THREAT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

SHOWERS AND THUNDERSTORMS WILL PERSIST ACROSS CENTRAL INDIANA
MONDAY THROUGH AT LEAST TUESDAY. LOCALLY HEAVY RAINS AND FLOODING
WILL BE THE MAIN THREAT WITH ANY STORMS. AN ADDITIONAL ONE TO TWO
INCHES OF RAIN IS EXPECTED TONIGHT THROUGH TUESDAY WITH LOCALLY HIGHER
AMOUNTS LIKELY.

.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)

INZ060>065-067>072-281945-
SULLIVAN-GREENE-MONROE-BROWN-BARTHOLOMEW-DECATUR-KNOX-DAVIESS-
MARTIN-LAWRENCE-JACKSON-JENNINGS-
244 PM CDT SUN AUG 27 2006 /344 PM EDT SUN AUG 27 2006/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA SOUTH OF
INTERSTATE 70.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT THIS EVENING.
THERE IS A CHANCE THAT A FEW STORMS COULD BECOME SEVERE WITH
DAMAGING WINDS, HOWEVER WIDESPREAD ORGANIZED SEVERE WEATHER IS NOT
EXPECTED. THE GREATER THREAT SHOULD BE HEAVY RAINS AND THE
POTENTIAL FOR FLOODING TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

SHOWERS AND THUNDERSTORMS WILL PERSIST MONDAY THROUGH AT LEAST
TUESDAY. LOCALLY HEAVY RAINS AND ADDITIONAL FLOODING WILL BE
POSSIBLE. AN ADDITIONAL ONE TO TWO INCHES OF RAIN WILL BE POSSIBLE
TONIGHT THROUGH TUESDAY WITH LOCALLY HIGHER AMOUNTS LIKELY.

.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