A strong cold front moved through Southeast Michigan during the peak heating of the day and led to another big event, especially for late August. Severe thunderstorms with large hail and damaging wind gusts impacted nearly all of Southeast Lower Michigan, including all neighboring marine areas.
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 DTX wrote it up.
A strong cold front moved through Southeast Michigan during the peak heating of the day and led to another big event, especially for late August. Severe thunderstorms with large hail and damaging wind gusts impacted nearly all of Southeast Lower Michigan, including all neighboring marine areas. A couple of storms across the Thumb showed rotation and prompted the issuance of a couple of tornado warnings. No tornadoes were reported. Lightning struck the National Weather Service office during this event, causing total damages in excess of $15K.
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 Detroit, MI wrote its last area forecast discussion before the first event at Aug 29, 12:46 PM EST, 1 hour 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 146 PM EDT WED AUG 29 2007 .AVIATION... A SLOW MOVING COLD FRONT DRAPED ACROSS CENTRAL MICHIGAN WILL DROP SLOWLY SOUTHWARD THROUGH THE SOUTHERN HALF OF MICHIGAN DURING THE AFTERNOON AND EARLY EVENING. THIS WILL BRING A QUICK SHOT OF THUNDERSTORMS TO AREA TERMINALS...PARTICULARLY FNT DET AND DTW. CEILINGS AND VISIBILITIES WILL DROP TO MVFR...POSSIBLY IFR...IN THUNDERSTORMS. BEHIND THE FRONT...SHOWERS AND MVFR CEILINGS CAN BE EXPECTED ALONG WITH A QUICK FLIP TO NORTH WINDS. RESTRICTED VISIBILITIES AND MVFR CEILINGS WILL LINGER INTO THE MORNING HOURS AS THE AIRMASS COOLS. && .PREV DISCUSSION...ISSUED 1147 AM EDT WED AUG 29 2007 UPDATE... CLEAR SKIES ACROSS THE FORECAST AREA THIS MORNING WILL ALLOW FOR AMPLE SURFACE HEATING AND FURTHER STEEPEN THE LOW LEVEL LAPSE RATES. SPC SECTOR ANALYSIS SHOWS 0-3KM LAPSE RATES IN THE THUMB AND TRI-CITES ARE CURRENTLY AROUND 6 C/KM...WITH FURTHER STEEPENING EXPECTED AREA WIDE THIS AFTERNOON BEFORE THE COLD FRONT APPROACHES. SPC SECTOR ANALYSIS ALSO SHOWS A FIRM CAP IN PLACE OVER ALL OF SOUTHEAST MICHIGAN...WHICH HAS BEEN SUFFICIENT ENOUGH TO HOLD BACK CU DEVELOPMENT SO FAR THIS AFTERNOON. QUESTION WILL BE IF WE CAN GENERATE ENOUGH LIFT AHEAD OF AND ALONG THE FRONT TO ALLOW THUNDERSTORMS TO DEVELOP. MODIFIED SOUNDING FOR DTX USING T/TD OF 90/67 YIELDED 2500 J/KG OF MLCAPE BY LATE AFTERNOON. MODIFIED SOUNDING FOR FNT WAS SIMILAR. MODELS ALSO INDICATING GOOD THETA-E ADVECTION AT ALL LEVELS JUST AHEAD OF THE FRONT...AND UPSTREAM SURFACE DEWPOINTS HAVE BEEN POOLING INTO THE UPPER 60S TO 70 JUST AHEAD OF THIS BOUNDARY. NAM/GFS ARE SHOWING MODEST LOW AND MID LEVEL FRONTOGENETICAL FORCING ALONG THE FRONT THIS AFTERNOON AND EARLY EVENING...PARTICULARLY ACROSS THE TRI-CITIES AND THUMB REGIONS. VERTICAL CIRCULATIONS WILL BE FURTHER ENHANCED BY DIVERGENCE ALOFT FROM THE RIGHT ENTRANCE REGION OF AN UPPER JET STREAK. WE ARE ALSO ANTICIPATING A 700MB SPEED MAX OF 45-50 KTS TO MOVE THROUGH SOUTHEAST MICHIGAN AROUND 18Z. THINK THAT THE COMBINATION OF THESE FORCING MECHANISMS CAN GENERATE ENOUGH LIFT TO PUNCH THROUGH THE CAP FOR DEVELOPMENT OF THUNDERSTORMS JUST AHEAD OF AND ALONG THE FRONT. ONE CON FOR ORGANIZED DEVELOPMENT OF SEVERE WEATHER...LOW LEVEL SHEAR IS NOT EXPECTED TO BE TOO IMPRESSIVE...WITH WINDS FROM THE SURFACE TO 850MB BELOW 15 KTS AND BECOMING INCREASINGLY UNIDIRECTIONAL. WE ARE EXPECTING THUNDERSTORMS TO DEVELOP OVER THE TRI-CITES AND THUMB REGIONS DURING THE EARLY TO MID AFTERNOON...AND SPREAD SOUTHWARD TO THE DETROIT METRO AREA BY 300 PM. SEVERE WEATHER IS POSSIBLE...WITH AT LEAST A FEW STRONG TO SEVERE STORMS EXPECTED. THE MAIN THREAT FROM THESE STORMS WILL BE DAMAGING WINDS AND LARGE HAIL. TORNADOES ARE NOT EXPECTED AS HELICITY LOOKS WAY TOO LOW AND ANTICIPATED LCL HEIGHTS AROUND 5000 FT ARE NOT FAVORABLE. PREV DISCUSSION...ISSUED 410 AM EDT WED AUG 29 2007 SHORT TERM...TODAY SURFACE RIDGE TO RETREAT FROM THE SOUTHEASTERN GREAT LAKES REGION THIS MORNING...WITH AN UPPER LAKES COLD FRONT MOVING IN THIS AFTERNOON. BELIEVE THAT THE GFS MAY BE TOO HASTY MOVING THIS FRONT ON THROUGH THE FORECAST AREA...GIVEN WEST TO SOUTHWEST FLOW IN THE MID LEVELS. AT 500 MB...MODELS SHOW WEAK EMBEDDED SHORTWAVE TROUGH MOVING IN THIS AFTERNOON. A WEDGE OF DEEP MOISTURE DEPICTED BY MODELS MOVING IN THIS AFTERNOON. THIS MOISTURE TO BE ACCOMPANIED BY A FEW UBAR/SEC OF OMEGA ASCENT IN THE LOW TO MID LEVELS...WEAK 850 TO 500 MB QVECTOR CONVERGENCE...WEAK 850 TO 700 MB FRONTOGENESIS...AND MODEST LOW LEVEL WIND CONVERGENCE BENEATH WEAK UPPER DIVERGENCE. MODELS IN GOOD AGREEMENT FOCUSING EARLIEST SHOWER/THUNDERSTORM CHANCES NORTH BY EARLY AFTERNOON THEN WORKING SOUTHWARD AHEAD OF THE COLD FRONT. MODELS SHOW CONVECTIVE INHIBITION NICELY ERODING BY AFTERNOON WITH CAPES TO NEAR 2K JOULES AND POSSIBLY MORE. 850 TO 700 MB LAPSE RATES ALSO CRANK UP TO 7 DEGREES C/KM OR SO...WITH TOTAL TOTALS APPROACHING 50. ZERO TO 6 KM BULK SHEAR LESS THAN 40 KNOTS...HELICITY ON THE WEAK SIDE...AND LOW LEVEL JET LARGELY ABSENT OVERHEAD. STILL...ROBUST INSTABILITY WITH MODEST FORCING SHOULD BE SUFFICIENT FOR SLIGHT CHANCE OF SEVERE STORMS. LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED TO BE ONGOING IN THE EASTERN PORTIONS OF THE CWA BY THIS EVENING WITH A DIMINISHING TREND AS WE LOSE DIURNAL SUPPORT AND THE 925MB FRONT PUSHES THROUGH. A SHORTWAVE WILL MOVE ACROSS NORTHERN LOWER BY 06Z HELPING TO ACCELERATE THIS FRONT TO THE SOUTH. DRIER AIR WILL BEGIN ADVECTING IN BEHIND THE FRONT WITH SKIES PARTIALLY CLEARING FROM THE NORTHWEST OVERNIGHT. HIGH PRESSURE WILL THEN BUILD INTO THE MIDWEST FOR THE DURATION OF THE WEEK WITH A LONG STRETCH OF QUIET WEATHER SETTING UP FOR SOUTHEAST MICHIGAN. 850MB TEMPS FALL TO BETWEEN 10 AND 12C BEHIND THE FRONT WHICH ARE RIGHT IN LINE WITH CLIMO FOR THE FIRST WEEKEND IN SEPTEMBER. THIS WILL SUPPORT VERY SEASONABLE HIGHS IN THE MID TO UPPER 70S ON THURSDAY AND FRIDAY WITH LOWS RUNNING SLIGHTLY BELOW NORMAL IN THE UPPER 40S TO LOW 50S. A NUMBER OF SHORTWAVES WILL BRUSH BY NORTHERN LAKE HURON THROUGH FRIDAY UNTIL THE UPPER LEVEL RIDGE AXIS BUILDS FAR ENOUGH TO THE EAST TO LIFT THE PREVAILING FLOW NORTH INTO ONTARIO. TEMPERATURES WILL SLOWLY WARM THROUGH THE LABOR DAY WEEKEND AS HIGH PRESSURE BUILDS TO THE EAST AND SOUTHWESTERLY RETURN FLOW GRADUALLY INCREASES. BY THE BEGINNING OF NEXT WEEK...MODELS INDICATE THE RIDGE WILL BE SUPPRESSED BY FAST ZONAL FLOW SETTING UP ACROSS SOUTHERN CANADA. AN EXPANSIVE SURFACE HIGH IS FORECAST TO EXTEND FROM THE MID ATLANTIC STATES TO THE MID MISSISSIPPI VALLEY PREVENTING THE RETURN OF MOISTURE FROM THE GULF. MODELS ARE STARTING TO HINT AT A COLD FRONT PUSHING SOUTH INTO LOWER MICHIGAN FROM LATE MONDAY INTO TUESDAY OF NEXT WEEK WITH THE 00Z/29 GFS BEING A FASTER AND MORE AGGRESSIVE OUTLIER. AT THIS TIME MOISTURE LOOKS TO BE LIMITED ALONG THE FRONTAL BOUNDARY AND WITH TIMING ALSO IN QUESTION WILL CHOOSE TO KEEP THE LABOR DAY FORECAST DRY. MARINE... SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE CENTRAL GREAT LAKES THROUGH THE DAY AS A COLD FRONT PUSHES SOUTH THROUGH THE REGION. A FEW OF THE STORMS MAY BE STRONG ON THE SOUTH HALF OF LAKE HURON...LAKE ST CLAIR AND LAKE ERIE FROM LATE THIS AFTERNOON INTO THIS EVENING. WINDS WILL SHIFT AROUND TO THE NORTH OVERNIGHT BUT WILL BE SLIGHTLY LESS THAN EARLIER EXPECTED DUE TO THE SHALLOW NATURE OF THE FRONT. WAVES WILL GRADUALLY INCREASE THROUGH THURSDAY ON THE SOUTH HALF OF THE LAKE WITH A PERSISTENT NORTHERLY FLOW AND INCREASING INSTABILITY AND WILL HAVE TO KEEP AN EYE OUT FOR SMALL CRAFT CONDITIONS. HIGH PRESSURE WILL RETURN TO THE AREA BY THE END OF THE WEEK WITH GOOD BOATING CONDITIONS EXPECTED FOR THE WEEKEND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && AVIATION.....OROW UPDATE.......OROW SHORT TERM...DWD LONG TERM....KAHL MARINE.......KAHL YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 442 AM EDT WED AUG 29 2007 MIZ047>049-053>055-060>063-068>070-075-076-082-083-300845- MIDLAND-BAY-HURON-SAGINAW-TUSCOLA-SANILAC-SHIAWASSEE-GENESEE-LAPEER- ST. CLAIR-LIVINGSTON-OAKLAND-MACOMB-WASHTENAW-WAYNE-LENAWEE-MONROE- 442 AM EDT WED AUG 29 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST MICHIGAN. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM MID AFTERNOON THROUGH THIS EVENING AS A COLD FRONT MOVES ACROSS LOWER MICHIGAN. THERE IS A SLIGHT CHANCE OF SEVERE WEATHER WITH THESE THUNDERSTORMS WITH THE MAIN HAZARD BEING WIND GUSTS TO 60 MPH. MARGINALLY SEVERE SIZE HAIL...BRIEF HEAVY RAIN...AND LIGHTNING WILL ALSO ACCOMPANY THESE THUNDERSTORMS. STORM MOTION WILL BE TO THE EAST AT 20 MPH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... DISPATCHERS PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON. LCZ422-423-460-LEZ444-LHZ421-422-441>443-462>464-300845- ST. CLAIR RIVER-DETROIT RIVER-LAKE ST. CLAIR- MICHIGAN WATERS OF LAKE ERIE-OUTER SAGINAW BAY-INNER SAGINAW BAY- PORT AUSTIN TO HARBOR BEACH MI-HARBOR BEACH TO PORT SANILAC MI- PORT SANILAC TO PORT HURON MI- LAKE HURON OFFSHORE BEYOND 5 NM FROM PORT AUSTIN TO HARBOR BEACH MI- LAKE HURON OFFSHORE BEYOND 5 NM FROM HARBOR BEACH TO PORT SANILAC MI- LAKE HURON OFFSHORE BEYOND 5 NM FROM PORT SANILAC TO PORT HURON MI- 442 AM EDT WED AUG 29 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR LAKE ST CLAIR...THE MICHIGAN WATERS OF LAKE ERIE AND LAKE HURON. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM MID AFTERNOON THROUGH THIS EVENING AS A COLD FRONT MOVES THROUGH THE CENTRAL GREAT LAKES. THERE IS A SLIGHT CHANCE OF SEVERE WEATHER WITH THESE THUNDERSTORMS WITH THE MAIN HAZARD BEING WIND GUSTS TO 60 MPH. MARGINALLY SEVERE SIZE HAIL...BRIEF HEAVY RAIN...AND LIGHTNING WILL ALSO ACCOMPANY THESE THUNDERSTORMS. STORM MOTION WILL BE TO THE EAST AT 20 MPH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY A SMALL CRAFT ADVISORY MAY BE NEEDED BY EARLY THURSDAY FOR THE NEARSHORE WATERS OF LAKE HURON FROM PORT AUSTIN TO HARBOR BEACH AS WAVES INCREASE BEHIND THE FRONT. .SPOTTER INFORMATION STATEMENT... DISPATCHERS PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY... SPOTTER ACTIVATION MAY BE NEEDED. KAHL YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
The Detroit radar (KDTX), 91 km away, was scanning. The volume nearest the first event began at 19:08 UTC.
24 thunderstorm wind, 6 hail, 2 lightning. Local standard time, as filed.
A trained spotter reported many tree branches 3 to 5 inches in diameter down in Fairgrove. The local Police Chief reported the heaviest damage just outside the village limits where trees and power lines were down. A temporary storage shed was also destroyed by the wind.
A trained spotter estimated the wind gusts at 60 MPH.
A trained spotter reported a tree down.
Trained spotters reported trees and power lines down.
A trained spotter reported large tree branches down.
A trained spotter estimated the wind gusts at 60 MPH.
A trained spotter estimated the wind gusts at 60 MPH.
Law enforcement reported trees and power lines down.
Law enforcement reported a few trees down.
Trained spotters reported trees 2 to 3 feet in diameter down.
A trained spotter reported a large tree and power lines down at the intersection of Roosevelt and Saginaw Roads.
A trained spotter estimated the wind gusts at 70 MPH.
A trained spotter reported a large tree and several tree branches down.
A trained spotter measured a 62 MPH wind gust.
Law enforcement reported trees and power lines down.
Broadcast media reported large tree branches down.
The local newspaper reported trees and power lines down across Little Cedar Creek Drive.
A trained spotter reported large tree branches down.
The local newspaper reported a home destroyed by fire after being struck by lightning during a violent thunderstorm. Total property damages were estimated at roughly $175K.
A trained spotter reported a tree branch 8 inches in diameter down.
A trained spotter reported a tree and power lines down.
Law enforcement reported trees down.
Lightning struck the National Weather Service office. Total damages to upper air equipment, Doppler Radar, telephone services, and miscellaneous items were estimated at approximately $16K.
Law enforcement reported a tree down.
A trained spotter measured a 58 MPH wind gust.
A trained spotter reported trees and power lines down.
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, August 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: 57064, 57144, 57214, 57217, 57218, 57201, 57119, 57146, 57121, 57068, 57149, 57070, 57103, 57150, 57151, 57086, 57124, 57096, 57128, 57079, 57196, 59079, 57104, 59075, 57110, 57115, 57219, 57112, 57191, 57118, 57132, 57198.