Weak, but persistent warm air advection moved into the region extending from eastern Iowa into northern Indiana. Extreme instability developed to the west across Illinois where CAPEs exceeded 5000 j/kg and LI's reached -10 C.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS IWX wrote it up.
Weak, but persistent warm air advection moved into the region extending from eastern Iowa into northern Indiana. Extreme instability developed to the west across Illinois where CAPEs exceeded 5000 j/kg and LI's reached -10 C. As the instability advected east along this area of isentropic lift, thunderstorms rapidly developed. Due to the slow movement of these storms as well as precipitable water values at or above 2 inches, widepsread heavy rain was observed in many locations. With northwest flow aloft, the line drifted south and accelerated as a wave approached the area. While flooding ended up the main threat, embedded wind damage was observed in a few of the stronger storms.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Northern Indiana wrote its last area forecast discussion before the first event at Jul 18, 7:05 PM EST, 1 hour 50 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 805 PM EDT WED JUL 18 2007 .UPDATE... SHOWERS AND THUNDERSTORMS DEVELOPING IN H85 THETA-E ADVECTION ZONE OVER NRN IL/IN AND SRN MI THIS EVE. EXPECT THIS ACTIVITY TO CONTINUE PAST DARK AS THE LOW LEVEL WARM MOIST ADVECTION MOVES ACROSS THE NRN PORTION OF THE AREA. THUS, HAVE INCREASED POPS TO LIKELY ACROSS NRN PORTIONS OF THE AREA WITH RECENT UPDATE. && .PREV DISCUSSION... /ISSUED 743 PM EDT WED JUL 18 2007/ AVIATION... LOW LEVEL WARM/MOIST ADVECTION WAS HELPING TO TRIGGER SCT SHOWERS AND THUNDERSTORMS OVER NRN IN/IL THIS EVE. THIS CONVECTION SHOULD AFFECT BOTH TERMINALS DURING THE EVE, BUT BASED ON EXTRAPOLATION OF CURRENT ACTIVITY EXPECT TS WILL REMAIN NORTH OF FWA AND ONLY MENTIONED SHRA THERE ATTM. MORE WIDESPREAD TSRA EXPECTED LATE TONIGHT AS A SHRTWV OVER ERN SD MOVES INTO NRN IL/IN. CDFNT WILL MOVE THROUGH NRN INDIANA TOMORROW AFTN. 18Z NAM SUGGESTS BEST INSTABILITY WILL BE WELL AHEAD OF THE FRONT AND SOUTH OF THE TERMINALS DUE TO STABILIZING INFLUENCE OF EARLY MORNING CONVECTION ASSOCIATED WITH THE SHRTWV LATE TONIGHT AND EARLY THU, SO ATTM NO MENTION OF TSRA IN TAFS WITH FROPA. PREV DISCUSSION... SHORT TERM...TONIGHT AND TOMORROW. LATEST SFC ANALYSIS SHOWS QUASI-STATIONARY FRONTAL BOUNDARY EXTENDING ACROSS NORTHERN PORTIONS OF NEB AND IOWA...SOUTH CENTRAL WIS AND CENTRAL LWR MICHIGAN. WARM HUMID UNSTABLE AIRMASS OVER THE AREA ALONG WITH OLD OUTFLOW BOUNDARIES HAVE TRIGGERED A FEW TSRA THIS MORNING/EARLY AFTERNOON...BUT NOTHING SUSTAINED. IR SAT LOOP SHOWING REMNANTS OF LAST NIGHTS MCS OVER CENTRAL INDIANA WITH NEW CONVECTION FIRING BACK OVER EASTERN SD. EXPECT THIS NEW DEVELOPMENT TO BE THE MAIN PLAYER FOR SHORT TERM AS SHORT WAVE COMING OVER UPPER RIDGE WILL ADD ADDL DYNAMICS TO SUPPORT ORGANIZED CONVECTION. MODELS IN DECENT AGREEMENT ON NUDGING THETA E RIDGE FURTHER NORTH INTO OUR AREA...THIS ALONG WITH SFC WAVE MOVING EASTWARD ALONG BOUNDARY TONIGHT SHOULD HELP STEER CONVECTION INTO OUR AREA AND PREVENT THE SOUTHEAST DIVE MCS HAVE TAKEN IN PREVIOUS NIGHTS. STABLE BOUNDARY LAYER DEVELOPING IN THE EVENING WILL ALLOW STORMS DEVELOPING TO THE WEST TO BECOME ELEVATED WITH TIME...ORGANIZING INTO ANOTHER MCS. PLENTY OF INSTABILITY ABOVE THE BOUNDARY LAYER...MODEL SOUNDINGS HAVE CAPES AOA 2000J/KG OVERNIGHT SO SHOULD HAVE NO TROUBLE SUSTAINING ONGOING CONVECTION...UNIDIRECTIONAL WIND PROFILE AND ELEVATED NATURE OF CONVECTION WILL HAVE DAMAGING WINDS AS THE PRIMARY THREAT. MOISTURE POOLING ALONG FRONTAL BOUNDARY WILL HAVE PW GT 2 INCHES SO HEAVY RAIN WILL ALSO BE OF SOME CONCERN. IF THIS SCENARIO PLAYS OUT...WILL BE WELL INTO THE NIGHT BEFORE MCS ARRIVES...WILL STAY WITH CURRENT GRIDS WHICH HAVE BEST CHANCE STARTING AT 06Z. STILL PREFER TO STAY WITH LIKELY POPS AND ALLOW EVENING SHIFT TO UPGRADE TO CATEGORICAL ONCE TRACK OF MCS BECOMES CLEAR...OR CONVERSELY DOWNGRADE IF THINGS DONT PAN OUT. WARM AND HUMID TONIGHT WITH LOWS AROUND 70F...FRONT PASSING THROUGH TOMORROW AFTERNOON WILL KEEP TEMPS IN U70S NW CWA...CLOUDS AND LINGERING PRECIP IN SOUTHERN CWA WILL LIMIT TEMPS TO L80S. LONG TERM...TOMORROW NIGHT THROUGH WEDNESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT OVER THE LAST FEW RUNS IN MOVING THE COLD FRONT SOUTHWARD OUT OF THE AREA TOMORROW EVENING. THE ONLY QUESTION IS THE EXACT SPEED OF THE FRONT AND WILL ANY RAIN BE AROUND THE SOUTHERN PART OF THE CWA YET EARLY TOMORROW EVENING. THE MODELS HAVE BEEN JUMPING THAT RAIN AROUND THE SOUTHERN PART OF THE CWA...SO HAVE PUT IN A SMALL CHANCE FOR RAIN IN THE EARLY EVENING HOURS FOR THE POSSIBILITY OF SOME RAIN NEAR/AROUND THE SOUTHERN COUNTIES OF OUR CWA. THIS COLLABORATES WELL WITH OUR NEIGHBORS ALSO. THEN SKIES BEGIN CLEARING UP THROUGH THE NIGHT AS HIGH PRESSURE MOVES IN FROM THE NORTH. THE HIGH PRESSURE THEN IS PROGGED TO STAY RIGHT OVER US THROUGH NEXT WEDNESDAY. TEMPERATURES ARE EXPECTED TO WARM UP NEXT WEEK. MONDAY 850MB TEMPS ARE FORECASTED TO BE 15 TO 16 DEGREES CELSIUS...17 TO 18 DEGREES ON TUESDAY...AND 19 TO 20 DEGREES ON WEDNESDAY. THE UPPER LEVEL PATTERN IS NOT LOOKING TO CHANGE MUCH OVER THE EXTENDED PERIOD. THE REST OF THIS WEEK WILL SEE A TROUGH OVER BOTH THE WEST COAST AND EAST COAST WHILE A RIDGE OCCUPIES THE CENTRAL PART OF THE COUNTRY. THEN NEXT WEEK THE UPPER PATTERN CHANGES ONLY SLIGHTLY. THE EAST COAST TROUGH IS PROGGED TO FORM INTO A CLOSED LOW AS THE UPPER RIDGE EXPANDS TO OVER THE SOUTHWESTERN PART OF THE COUNTRY. THEREFORE A DRY EXTENDED. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && SHORT TERM...LOGSDON LONG TERM....LOTHAMER AVIATION/UPDATE...JT
HAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE NORTHERN INDIANA 427 PM EDT WED JUL 18 2007 INZ004>009-012>018-020-022>027-032>034-MIZ078>081-OHZ001-002-004-005- 015-016-024-025-192030- ST. JOSEPH IN-ELKHART-LAGRANGE-STEUBEN-NOBLE-DE KALB-STARKE-PULASKI- MARSHALL-FULTON IN-KOSCIUSKO-WHITLEY-ALLEN IN-WHITE-CASS IN-MIAMI- WABASH-HUNTINGTON-WELLS-ADAMS-GRANT-BLACKFORD-JAY-CASS MI- ST. JOSEPH MI-BRANCH-HILLSDALE-WILLIAMS-FULTON OH-DEFIANCE-HENRY- PAULDING-PUTNAM-VAN WERT-ALLEN OH- INCLUDING THE CITIES OF...SOUTH BEND...MISHAWAKA...ELKHART... GOSHEN...LAGRANGE...TOPEKA...ANGOLA...KENDALLVILLE...LIGONIER... AUBURN...GARRETT...KNOX...NORTH JUDSON...WINAMAC...FRANCESVILLE... PLYMOUTH...BREMEN...ROCHESTER...WARSAW...WINONA LAKE... COLUMBIA CITY...SOUTH WHITLEY...FORT WAYNE...MONTICELLO... BROOKSTON...LOGANSPORT...PERU...WABASH...NORTH MANCHESTER... HUNTINGTON...BLUFFTON...OSSIAN...DECATUR...BERNE...MARION... HARTFORD CITY...MONTPELIER...PORTLAND...DOWAGIAC...CASSOPOLIS... STURGIS...THREE RIVERS...COLDWATER...HILLSDALE...BRYAN...WAUSEON... ARCHBOLD...DEFIANCE...NAPOLEON...PAULDING...ANTWERP...OTTAWA... PANDORA...VAN WERT...DELPHOS...LIMA 427 PM EDT WED JUL 18 2007 /327 PM CDT WED JUL 18 2007/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST OHIO... NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN. .DAY ONE...LATE THIS AFTERNOON AND TONIGHT... SCATTERED THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON AND THIS EVENING. ISOLATED SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE. THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD LATE TONIGHT. SOME OF THESE STORMS MAY BE SEVERE. HEAVY RAINFALL IS ALSO POSSIBLE WITH THE STORMS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SEVERE THUNDERSTORMS ARE POSSIBLE AGAIN ON THURSDAY...ESPECIALLY SOUTH OF A LINE FROM PLYMOUTH TO WAUSEON. TORRENTIAL RAINFALL MAY ALSO ACCOMPANY THE STRONGER STORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED...MAINLY LATE TONIGHT AND THURSDAY. && STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...OR CHECK OUR WEB SITE AT WWW.WEATHER.GOV/IWX INZ003-LMZ043-046-061-MIZ077-192030- LA PORTE-NEW BUFFALO MI TO ST JOSEPH MI- MICHIGAN CITY IN TO NEW BUFFALO MI- MICHIGAN CITY IN TO ST JOSEPH MI OUT TO MID LAKE-BERRIEN- INCLUDING THE CITIES OF...MICHIGAN CITY...LA PORTE...NILES... BENTON HARBOR...ST. JOSEPH...BUCHANAN 427 PM EDT WED JUL 18 2007 /327 PM CDT WED JUL 18 2007/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST INDIANA... SOUTHWEST LOWER MICHIGAN AND EXTREME SOUTHEASTERN LAKE MICHIGAN. .DAY ONE...LATE THIS AFTERNOON AND TONIGHT... SCATTERED THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON AND THIS EVENING. ISOLATED SEVERE STORMS WITH STRONG DAMAGING WINDS AND LARGE HAIL ARE POSSIBLE. THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD LATE TONIGHT. SOME OF THESE STORMS MAY BE SEVERE. HEAVY RAINFALL IS ALSO POSSIBLE WITH THE STORMS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE AGAIN ON THURSDAY MORNING. TORRENTIAL RAINFALL MAY ALSO ACCOMPANY THE STRONGER STORMS. THERE IS AN INCREASED RISK OF RIP CURRENTS ALONG THE SOUTHEAST LAKE MICHIGAN SHORELINE THURSDAY AFTERNOON AS NORTH WINDS INCREASE AND WAVES BUILD TO 3 TO 5 FEET BY EVENING. A SMALL CRAFT ADVISORY MAY BE NEEDED THURSDAY AFTERNOON THROUGH FRIDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED...MAINLY LATE TONIGHT. && STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...OR CHECK OUR WEB SITE AT WWW.WEATHER.GOV/IWX
The Northern Indiana radar (KIWX), 76 km away, was scanning. The volume nearest the first event began at 01:54 UTC.
1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Numerous trees were reported down in the southeast part of the county.
A report of 3.61 inches of rain was received in the Niles area, with several roads having signs of partial damage from flowing water over them. Damage is estimated at $25,000.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2007Every state in 2007This day in weather historyWarnings in Michigan, July 2007
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 34865, 34866.