Hail and Damaging Winds in Indiana, August 18, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
225 AM EST WED AUG 18 2004

.DISCUSSION...

FOCUS REMAINS ON PRECIP CHCS THROUGH SAT.

MODEL GUIDANCE REMAINS IN DECENT AGREEMENT WITH HANDLING OF MAJOR
FEATURES THROUGH THE PERIOD. ONLY ISSUE CONTINUES TO BE THE GFS
CONVECTIVE FEEDBACK AND ASSOCIATED ERRONEOUS DEEPENING OF SFC LOW
COME FRI-SAT. WILL THEREFORE LEAN TOWARD THE ETA SFC FEATURES. AS
FOR PRECIP...ALL IN GENERAL AGREEMENT WITH MINOR TIMING DIFFERENCES
AND FOR TEMPS...ETA CONTINUES TO BE TOO WARM.

WATER VAPOR SATELLITE SHOWS SHORTWAVE TROUGH ACROSS IL RACING SE.
850-700MB WAA AND ASSOCIATED ISENTROPIC UPGLIDE AIDING IN
THUNDERSTORM DEVELOPMENT ACROSS THE CWA AT THIS TIME. TIMING OF THIS
FEATURE SUGGESTS THAT SCATTERED THUNDERSTORMS SHOULD PERSIST INTO
THE MID MORNING HOURS BEFORE THE FORCING WEAKENS AS THE WAVE PASSES
EAST. WILL SHOTGUN 30 POPS TODAY AND WILL KEEP GOING TEMPS WHICH
AGREE WITH NGM/MAV GUIDANCE.  ATTENTION THEN TURNS TO INTENSE UPPER
TROUGH WHICH WILL FORCE A STRONG COLD FRONT SOUTHEAST INTO THE
REGION TONIGHT. ASSOCIATED 80KT MIDLVL JET WILL PROVIDE 30-40KTS OF
BULK SHEAR WHILE CAPE SHOULD RANGE IN THE 1000-2000 J/KG RANGE THIS
EVENING. THIS IS A FAVORABLE COMBINATION FOR ORGANIZED STORMS/SEVERE
THREAT. GREATEST RISK SHOULD BE ACROSS THE NORTHERN THIRD CLOSER TO
ANY SQUALL LINE THIS EVENING/EARLY HOURS OF TONIGHT. SOME HINT OF A
WEAK SHORTWAVE TROUGH NOW ACROSS NEB THAT MAY ALSO MOVE ACROSS THE
AREA TONIGHT ENHANCING LIFT. IN A NUTSHELL, LIKELY CHCS FOR STORMS
ACROSS THE NORTHERN THIRD OF THE CWA TONIGHT...40 PERCENT FOR THE
INDY METRO AREA.

ON THURSDAY...FRONT WILL SAG AND STALL ACROSS CENTRAL INDIANA.
DYNAMIC FORCING WEAKENS HOWEVER, DIURNAL TYPE CONVECTION WILL REMAIN
A THREAT INTO FRI AS MOISTURE POOLS ALONG THE FRONT. WILL KEEP
GENERIC 20-40 CHCS GIVEN PROXIMITY OF FRONT. BOTH GFS/ETA INDICATING
THAT A SFC LOW WILL TRACK NORTHEAST ALONG THE FRONT LATER FRI INTO
SAT. ASIDE FROM TONIGHT, THIS WILL PROVIDE THE BEST CHC FOR RAINFALL
TO CENTRAL INDIANA. COOL DRY HIGH PRESSURE WITH ORIGINS ACROSS THE
PRAIRIE PROVINCES OF CANADA WILL THEN MOVE INTO THE STATE SAT NIGHT
AND SUN.

RATHER PROGRESSIVE LONGWAVE FLOW MAY ACT TO BRING ANOTHER WAVE INTO
THE REGION COME NEXT MON-TUES. THIS COULD BRING ANOTHER CHC FOR
STORMS AS A COLD FRONT PASSES DURING MON-TUES TIME FRAME.

&&

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

&&

CO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
625 AM EST WED AUG 18 2004

INZ021-028>031-035>044-191124-
BOONE-CARROLL-CLINTON-DELAWARE-FOUNTAIN-HAMILTON-HOWARD-MADISON-
MONTGOMERY-PARKE-RANDOLPH-TIPPECANOE-TIPTON-VERMILLION-WARREN-
625 AM EST WED AUG 18 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL RE-DEVELOP ACROSS ILLINOIS LATER THIS
AFTERNOON. THE STORMS WILL MOVE SOUTHEAST INTO PORTIONS OF INDIANA
THIS EVENING. SOME OF THE STORMS WILL BE CAPABLE OF PRODUCING
DAMAGING WINDS ALONG WITH LARGE HAIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH NEXT WEDNESDAY.

THUNDERSTORMS WILL BE POSSIBLE THURSDAY THROUGH EARLY SATURDAY. SOME
STORMS THURSDAY AND FRIDAY COULD BE SEVERE. STAY TUNED.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS MAY BE NEEDED AFTER 4 PM TODAY.

INZ045>049-051>057-060>065-067>072-191124-
BARTHOLOMEW-BROWN-CLAY-DAVIESS-DECATUR-GREENE-HANCOCK-HENDRICKS-
HENRY-JACKSON-JENNINGS-JOHNSON-KNOX-LAWRENCE-MARION-MARTIN-MONROE-
MORGAN-OWEN-PUTNAM-RUSH-SHELBY-SULLIVAN-VIGO-
625 AM EST WED AUG 18 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA TODAY AND
AGAIN TONIGHT. ALTHOUGH A FEW STORMS COULD PRODUCE LARGE
HAIL...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED. THE GREATER RISK
FOR SEVERE WEATHER IS EXPECTED TO REMAIN NORTH OF THE AREA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH NEXT WEDNESDAY.

THUNDERSTORMS WILL BE POSSIBLE THURSDAY THROUGH EARLY SATURDAY. SOME
OF THE STORMS ON THURSDAY AND FRIDAY COULD BE SEVERE. STAY TUNED.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE URGED TO LISTEN FOR UPDATED FORECASTS FOR THE POTENTIAL
FOR SEVERE WEATHER OVER THE NEXT 48 HOURS.