A large upper low over the area caused numerous slow moving thunderstorms to develop during the afternoon of August 1st. The severe thunderstorms produced hail and wind damage.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 large upper low over the area caused numerous slow moving thunderstorms to develop during the afternoon of August 1st. The severe thunderstorms produced hail and wind damage.
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 1, 10:36 AM EST, 1 hour 54 minutes earlier.
SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1136 AM EDT FRI AUG 1 2003 A VERTICALLY STACKED UPPER LEVEL LOW PRESSURE SYSTEM REMAINS CENTERED NEAR THE ARROWHEAD OF MINNESOTA. THIS MORNINGS RAOBS INDICATED AN 850MB THETA-E AXIS ACROSS EASTERN WISCONSIN/WESTERN LOWER MICHIGAN...WHICH LED TO SOME CONVECTION EARLIER THIS MORNING. THE VISIBLE SATELLITE LOOP AND DTX RADAR SHOWS A WELL DEFINED OUTFLOW BOUNDARY FROM NORTHERN HURON COUNTY TO JUST SOUTH OF GRAND RAPIDS. THIS OUTFLOW BOUNDARY IS REMNANTS OF THIS MORNINGS CONVECTION. SURFACE DEWPOINTS WELL IN THE SIXTIES SOUTH OF THIS BOUNDARY ALONG WITH PLENTY OF SUNSHINE HAS LED TO QUITE A BIT OF INSTABILITY OVER SE LOWER MICHIGAN. LAPS SOUNDINGS ALREADY SHOW CAPE APPROACHING 2K J/KG SOUTHEAST OF THE BOUNDARY...WITH THE CAPPING INVERSION NEARLY GONE. MODIFIED 12Z KDTX SOUNDING FOR MID 80S/UPPER 60S SHOWED 3200 J/KG CAPE. ALTHOUGH FORECAST AFTERNOON SOUNDINGS SHOW ONLY WEAK SHEAR...STRONG INSTABILITY WILL LEND ITSELF TO THE POTENTIAL FOR PULSE-TYPE SEVERE STORMS THIS AFTERNOON. GIVEN THE CONVERGENCE ALONG THE OUTFLOW...SPC HAS PLACED MOST OF SE MICHIGAN IN A SEVERE THUNDERSTORM WATCH UNTIL 4 PM. AS FOR THE ZONES AND GRIDDS...ONLY UPDATES FOR THIS AFTERNOON WILL BE TO EXTEND THE LIKELY POPS FARTHER SE GIVEN THE APPROACHING OUTFLOW BOUNDARY. I WILL ALSO LOWER TEMPS A COUPLE OF DEGREES ACROSS THE TRI CITIES GIVEN THIS MORNING CONVECTION. CONSIDINE ...3 AM FORECAST DISCUSSION... 00Z RAOBS/WATER VAPOR LOOP SHOW UPPER LOW NEAR THE MINNESOTA ARROWHEAD...WITH A SHORTWAVE SWINGING AROUND IT ACROSS WISCONSIN. SURFACE ANALYSIS SHOWS BROAD LOW OVER THE WESTERN GREAT LAKES...WHICH WITH A VARIETY OF FRONTS...TROUGHS...AND OUTFLOWS LEADS TO A COMPLICATED SURFACE PATTERN OVER THE REGION. REGIONAL RADARS SHOW THUNDERSTORMS ONGOING FROM IOWA/ILLINOIS THROUGH WISCONSIN AND NORTHERN MICHIGAN...BUT WITH SOUTHEAST MICHIGAN RELATIVELY CLEAR. IR SATELLITE SHOW MID/HIGH CLOUDS FROM WESTERN CONVECTION BEGINNING TO SPREAD ACROSS THE STATE. MAIN FORECAST FOCUS IS WITH PRECIP POTENTIAL THROUGH THE ENTIRE FORECAST PERIOD...AS SYSTEM OVER THE WESTERN GREAT LAKES TAKES QUITE A WHILE TO SLIDE THROUGH THE REGION DUE TO A PERSISTENT REX BLOCK. CURRENT THUNDERSTORMS ACROSS WISCONSIN/LAKE MICHIGAN ARE OCCURRING ALONG AN AXIS OF 850MB/700MB THETA-E ADVECTION...NEAR LEADING EDGE OF 500MB COLD POOL WITH 700-500MB LAPSE RATES NEAR 6.5C/KM. ALSO DECENT 850-500MB QVECTOR CONVERGENCE AHEAD OF THE SHORTWAVE. OVERALL THESE PARAMETERS DO NOT MAINTAIN THEIR STRENGTH AS WE TRANSLATE FARTHER EAST DURING THE DAY...WITH COOL POOL HOLD BACK NEAR THE UPPER LOW AND THETA-E GRADIENT NOT AS TIGHT. MOISTURE CONVERGENCE CONTINUES...AS WELL AS DESTABILIZATION WITH DAYTIME HEATING WITH CAPES BREAKING 2KJ/KG AND SURFACE LIS DROPPING BELOW -6C. STILL FIND IT HARD TO ARGUE AGAINST NUMEROUS POPS THIS AFTERNOON/EVENING. GIVEN DRY AIR AND GENERAL SUBSIDENCE FROM LEFT ENTRANCE OF 300MB JET OVER THE LOWER LAKES...CIRRUS UPSTREAM HAS HAD A DIFFICULT TIME MAKING IT INTO THE CWA. WILL KEEP THIS IN MIND AS THE JET CONTINUES TO MOVE EAST THIS MORNING...AND STILL KEEP ONLY SCATTERED POPS ACROSS THE SOUTHEASTERN CWA FOR THIS AFTERNOON /BUT STILL LIKELY FOR TONIGHT/. DESPITE WEAK WARM ADVECTION COMPARED TO YESTERDAY...ADDITIONAL CLOUD COVER SHOULD KEEP HIGH TEMPERATURES NEAR TO A COUPLE DEGREES COOLER THAN THOSE OBSERVED YESTERDAY. BESIDES PRECIP COVERAGE/CHANCES...SEVERE POTENTIAL IS ALSO A CONCERN FOR THIS AFTERNOON/EVENING. WE LOOK TO HAVE DECENT INSTABILITY AND A CHOICE OF BOUNDARIES FOR INITIATION...BUT 00Z MODEL RUN HAS BACKED OFF ON THE WIND FIELDS. HODOGRAPH/LOW-LEVEL SHEAR IS NOT AS IMPRESSIVE AS PREVIOUS RUNS. 850MB JET ONLY APPROACHES 20KTS...AND STRONGEST 500MB JET DIVES SOUTH OF THE REGION WITH BARELY 20KTS OVER LOWER MICHIGAN. UPPER DIVERGENCE INCREASES THOUGH UNDER LEFT-EXIT OF APPROACHING 300MB JET. PRECIPITABLE WATERS INCREASE WITH CONTINUED MOISTURE ADVECTION /APPROACHING 1.5/ LATE THIS AFTERNOON/MORE TOWARD EVENING. FREEZING LEVELS ARE ALSO RUNNING AROUND 12KFT. OVERALL IMPRESSION WOULD BE A MARGINAL PULSE-TYPE EVENT WITH THREATS OF BOTH WIND OR HAIL. AS MENTIONED ABOVE...WILL CARRY LATE AFTERNOON LIKELY POPS THOUGH THE EVENING. WITH UNCERTAINTY AS TO EXACT TIMING AND CHANCES FOR REDEVELOPMENT...WILL HOLD ONTO LIKELY THROUGH THE TONIGHT PERIOD. MAIN TIMEFRAME STILL LOOKS TO BE DURING THE EVENING. LITTLE CHANGE TO THE TEMPERATURE FORECAST...WITH LOWS IN THE 60S AGAIN TONIGHT...SIMILAR TO TONIGHT BUT A DEGREE OR TWO WARMER WITH ADDITIONAL MOISTURE FROM PRECIPITATION. UPPER LOW DROPS INTO WISCONSIN SATURDAY/SATURDAY NIGHT...WITH SURFACE LOW WOBBLING ACROSS LOWER MICHIGAN. ETA/GFS CONTINUE TO BE SIMILAR WITH THE OVERALL UPPER PATTERN...BUT WITH MASS DIFFERENCES THAT HAVE A NOTICEABLE IMPACT ON THE FORECAST. THERE LOOKS TO BE CONVECTIVE FEEDBACK IN SOME FASHION WITH BOTH THE ETA/GFS AT VARIOUS POINTS IN THE CYCLE. ETA INDICATES THE BEST CHANCE OF PRECIP TO BE SATURDAY NIGHT WITH THE SYSTEM WRAPPING UP OVER LOWER MICHIGAN. GFS SHOWS REPEAT PERFORMANCES OF NOCTURNAL MCSS ALONG DEVELOPING 850MB JETS TAKINGS SWIPES THROUGH THE REGION...ACROSS LAKE MICHIGAN CURRENTLY...ACROSS LOWER MICHIGAN TONIGHT...AND ACROSS WESTERN LAKE ERIE/LAKE ST CLAIR SATURDAY NIGHT. AS FAR AS CURRENT CONVECTION...THE GFS LOOKS TO HAVE THE BETTER HANDLE AS FAR AS QPF PLACEMENT ACROSS WISCONSIN/LAKE MICHIGAN. WITH THE UNCERTAINTY SURROUNDING THE VARIOUS SCENARIOS THAT COULD PLAY OUT...FEEL IT IS BEST TO HOLD ON THE SCATTERED POPS CURRENTLY IN THE FORECAST...UNDERCUTTING THE LIKELY/NEARLY CATEGORICAL POPS INDICATED BY THE ETA/GFS MOS GUIDANCE. .DTX...NONE. BRAVENDER EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE)
MIZ047>049-053>055-060>063-068>070-075-076-082-083-021200- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1119 AM EDT FRI AUG 1 2003 ...SEVERE THUNDERSTORM WATCH NUMBER 823 IN EFFECT UNTIL 4 PM FOR MOST OF SOUTHEAST MICHIGAN... THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST LOWER MICHIGAN .DAY ONE...THIS AFTERNOON AND TONIGHT A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL OF SOUTHEAST LOWER MICHIGAN EXCEPT BAY AND MIDLAND COUNTIES UNTIL 4 PM. FOR THIS AFTERNOON...NUMEROUS THUNDERSTORMS ARE EXPECTED NORTHWEST OF AN ANN ARBOR TO PORT HURON LINE...WITH SCATTERED THUNDERSTORMS EXPECTED TO THE SOUTHEAST. THUNDERSTORMS NOW OVER SOUTHWEST LOWER MICHIGAN WILL GRADUALLY SPREAD EAST...REACHING FLINT...OWOSSO AND THE TRI CITIES BY 1 PM...AND MOVING INTO THE DETROIT AREA AND THUMB SHORTLY AFTER 2 PM. SOME OF THESE STORMS WILL BE SEVERE...WITH WIND GUSTS TO 60 MPH AND HAIL TO 2 INCHES IN DIAMETER. STORMS WILL MOVE NORTHEAST AT 25 MPH. FOR TONIGHT...NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS ALL OF SOUTHEAST MICHIGAN. THESE STORMS ARE NOT EXPECTED TO BE SEVERE. HOWEVER...SOME OF THEM WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 40 MPH AND PEA SIZED HAIL. THEY WILL ALSO MOVE NORTHEAST AT 25 MPH. THESE STORMS ARE ASSOCIATED WITH AN UNSTABLE AIRMASS OVER THE REGION AHEAD OF A SLOW MOVING LOW PRESSURE SYSTEM OVER NORTHERN WISCONSIN. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR SATURDAY THROUGH WEDNESDAY. A SLOW MOVING LOW PRESSURE SYSTEM LINGERING OVER THE GREAT LAKES WILL BE RESPONSIBLE FOR THE PERSISTENT THREAT OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION HAS ALREADY OCCURRED. && STAY TUNED TO NOAA WEATHER RADIO...OR LOCAL MEDIA OUTLETS...FOR THE LATEST FORECAST INFORMATION FROM THE NATIONAL WEATHER SERVICE. YOU CAN ALSO OBTAIN THE LATEST FORECAST ON THE NATIONAL WEATHER SERVICE WEB SITE HTTP://WWW.CRH.NOAA.GOV/DTX/ (ALL LOWER CASE) CONSIDINE
The Detroit radar (KDTX), 75 km away, was scanning. The volume nearest the first event began at 17:29 UTC.
15 thunderstorm wind, 6 hail, 3 lightning. Local standard time, as filed.
A trained weather spotter estimated a thunderstorm wind gust of 60 mph.
A trained weather spotter estimated a 60 mph thunderstorm wind gust.
Spotters reported a 4 inch diameter tree blown down.
A trained weather spotter reported a 1 foot diameter tree down.
Spotters reported a 8 inch diameter tree blown down.
Spotters reported large tree limbs blown down.
An NWS employee reported multiple 6 inch tree limbs down.
A trained weather spotter reported small trees blown down.
A trained weather spotter reported trees blown down.
A trained weather spotter reported 5 inch tree limbs down.
An 11 year old boy was struck by lightning on Garry Road. CPR was performed on the boy, who later recovered.
A trained weather spotter reported a 65 mph thunderstorm wind gust.
Spotters reported several trees blown down.
Local law enforcement reported power lines down.
Spotters reported several large tree limbs down.
A woman was struck by lightning while loading groceries into her car. The woman was treated and released from the hospital.
A woman was struck by lightning and killed standing in her backyard.
Spotters reported several trees and power lines blown down.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Lightning, Lenawee | 2003-08-01 | 63 | Female | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2003Every state in 2003This day in weather historyWarnings in Michigan, August 2003
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: 5368523, 5368530, 5368531, 5368524, 5368525, 5368532, 5368533, 5368526, 5368534, 5368528, 5368527, 5368535, 5368536, 5368612, 5368607, 5368608, 5368529, 5368537, 5368606, 5368609, 5368613, 5368610, 5368614, 5368611.