Michigan, 2003

Hail and Damaging Winds in Michigan, July 21, 2003

July 21, 2003 · NWS DTX · 13 events in 8 counties and zones

A warm and unstable airmass lingered over southeast Michigan during the early morning hours of the 21st. Storms left over from the daytime were moving east along the Ohio border.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
13

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.

What happened

The episode as NWS DTX wrote it up.

A warm and unstable airmass lingered over southeast Michigan during the early morning hours of the 21st. Storms left over from the daytime were moving east along the Ohio border. An outflow boundary then moved north into Washtenaw and Wayne counties. This provided the focus for a severe storm in Washtenaw county. The best storm of the night got organized from another batch of activity along the Ohio border and formed into a nice supercell right on the Lenawee/Monroe county line.Although instability was initially minimized by morning cloud cover on the 21st, sunshine was able to filter through a thinning cirrus canopy by early afternoon. This, combined with a relatively warm and moist southwest flow, allowed temperatures to climb into the upper 70s and dewpoints to reach the mid 60s.A warm front draped along the I 69 corridor became the focus for numerous thunderstorms during the afternoon. Strong upper level winds lead to supercell development, producing damaging wind, large hail and very heavy rainfall as they moved slowly southeast into northern parts of metro Detroit by early evening.Thunderstorms also formed along a cold front in southwest Lower Michigan. This activity intensified as it moved into areas along and south of I 94 by early evening. A small bow echo eventually formed as this convective line tracked through Lenawee and Monroe counties. A number of reports of wind damage were reported with this activity. All significant thunderstorm activity exited the region by around 7 pm as the cold front swept southeast of the area.

What forecasters said that day

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 Jul 21, 2:00 PM EST, 15 minutes earlier.

Area forecast discussion, Jul 21, 2:00 PM EST, 15 minutes before
SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
300 PM EDT MON JUL 21 2003

FOCUS IS ON THE SHORT TERM AS CONVECTION CONTINUES TO BREAK OUT
AHEAD OF ADVANCING SHORT WAVE AND SURFACE FRONT THIS AFTERNOON. EAST
WEST SURFACE BOUNDARY ACROSS SOUTHERN LOWER WITH BETTER THAN 2K J/KG
POOLING ALONG THE BOUNDARY AS DEW POINTS START TO CLIMB TOWARD 70.
MID LEVEL WIND FIELDS ARE ALSO GRADUALLY INCREASING AS SHORT WAVE
AXIS APPROACHES... INCREASING CHANCES THAT CONVECTION WILL BECOME
MORE ORGANIZED WITH TIME. CONVECTION HAS BEEN RELATIVELY SLOW MOVING
THIS AFTERNOON.. AND SOME ALIGNMENT ALONG THE BOUNDARY HINTING
TOWARD THE POSSIBILITY OF SOME TRAIN ECHOING. THUS HAVE OPTED TO
BUMP UP QPF... AND MENTION POSSIBILITY OF HEAVY RAIN IN THE
FORECAST.

LOOKS LIKE CONVECTION WILL CONTINUE ACROSS MOST OF THE CWA...
PARTICULARLY IN THE SOUTH HALF... WELL INTO THE EVENING HOURS. AFTER
THAT WILL CUT BACK DRAMATICALLY ON POPS... AND THINGS SHOULD PRETTY
MUCH BE OVER BY 06 UTC. MAIN QUESTION AFTER THAT FOR TUESDAY AND
WEDNESDAY WILL BE ABILITY TO KICK OFF SCATTERED SHOWERS UNDER THE
UPPER COLD POOL. BOTH DAYS... AFTERNOON STABILITY INDICES POINT
TOWARD UNSTABLE ENOUGH PROFILES TO JUSTIFY SMALL POPS... ALTHOUGH A
FOCUSING MECHANISM WILL BE SOMEWHAT LACKING. HAVE OPTED TO
CONTINUE/INCLUDE SMALL POPS EACH AFTERNOON... AND REMOVE POPS FOR
THE MORE STABLE OVERNIGHT/MORNING PERIODS.

LITTLE CHANGE TO LATER PERIODS OF THE FORECAST... WITH A GENERALLY
COOLER THAN NORMAL TREND THROUGH THE WEEKEND.

.DTX...NONE.

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)
Hazardous weather outlook, Jul 21, 11:10 AM EST, 3 hours 5 minutes before
MIZ047>049-053>055-060>063-068>070-075-076-082-083-221000-

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1210 PM EDT MON JUL 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST LOWER MICHIGAN

.DAY ONE...THIS AFTERNOON AND TONIGHT

NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS ALL OF SOUTHEAST MICHIGAN
THIS AFTERNOON. LOCATIONS NEAR FLINT...OWOSSO AND THE TRI CITIES
WILL SEE THESE THUNDERSTORMS MOVE IN FROM THE WEST SHORTLY AFTER 1
PM. MEANWHILE...LOCATIONS ACROSS THE THUMB AND AROUND THE METRO
DETROIT AREA WILL SEE MORE NUMEROUS THUNDERSTORMS AFTER 3 PM.
THUNDERSTORMS WILL DIMINISH ACROSS THE AREA BY 8 PM THIS EVENING.
SOME OF THE STRONGER STORMS THIS AFTERNOON AND EARLY THIS EVENING
MAY PRODUCE WIND GUSTS TO 60 MPH AND HAIL TO 1 INCH IN DIAMETER.
FREQUENT LIGHTNING AND TORRENTIAL RAINFALL CAN BE EXPECTED WITH ANY
THUNDERSTORM THAT DEVELOPS THIS AFTERNOON. THIS MAY LEAD TO SOME
LOCALIZED FLOODING IN LOCATIONS ALONG AND SOUTH OF AN ANN ARBOR TO
DETROIT LINE DUE TO THE RAINFALL RECEIVED LAST NIGHT. THE
THUNDERSTORMS WILL MOVE EAST AT 20 MPH.

THESE THUNDERSTORMS ARE ASSOCIATED WITH A COLD FRONT AND WEAK LOW
PRESSURE SYSTEM THAT WILL SLOWLY BE MOVING EAST ACROSS THE STATE
THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ISOLATED THUNDERSTORMS ARE POSSIBLE TUESDAY AFTERNOON AND WEDNESDAY
AFTERNOON...BUT SEVERE WEATHER IS NOT EXPECTED.

THERE IS A CHANCE OF THUNDERSTORMS AGAIN ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EARLY THIS
EVENING.

&&

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 radar

The Detroit radar (KDTX), 32 km away, was scanning. The volume nearest the first event began at 19:15 UTC.

Open the radar archive at this moment

Event by event

7 hail, 6 thunderstorm wind. Local standard time, as filed.

Hail, Genesee

When
July 21, 2:15 PM EST
Where
Genesee County, 3 mi S of Davison
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
42.983, -83.517

Hail, Lapeer

When
July 21, 2:35 PM EST
Where
Lapeer County, Hadley
Measured
0.75 in hail
Reported by
GENERAL PUBLIC
Coordinates
42.950, -83.400

Thunderstorm Wind, Lapeer

When
July 21, 2:55 PM EST
Where
Lapeer County, Almont
Measured
55 kt (63 mph) estimated gust
Reported by
TRAINED SPOTTER
Coordinates
42.917, -83.033

Spotters reported several large trees blown down.

Hail, Lapeer

When
July 21, 2:55 PM EST
Where
Lapeer County, Almont
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
42.917, -83.033

Hail, St. Clair

When
July 21, 3:15 PM EST
Where
St. Clair County, 5 mi S of Capac
Measured
1.75 in hail
Reported by
GENERAL PUBLIC
Coordinates
42.950, -82.917

Thunderstorm Wind, St. Clair

When
July 21, 3:15 PM EST
Where
St. Clair County, 1 mi SE of Allenton
Measured
60 kt (69 mph) estimated gust
Reported by
LAW ENFORCEMENT
Coordinates
42.917, -82.933

Local law enforcement and media reported several large trees blown down. Most of the damage was around Hough Road. Trees were uprooted and soybean plants were stripped of their leaves.

Hail, Oakland

When
July 21, 3:20 PM EST
Where
Oakland County, Holly
Measured
0.75 in hail
Reported by
GENERAL PUBLIC
Coordinates
42.800, -83.617

Thunderstorm Wind, Oakland

When
July 21, 3:20 PM EST
Where
Oakland County, Holly
Measured
55 kt (63 mph) estimated gust
Reported by
GENERAL PUBLIC
Coordinates
42.800, -83.617

The public reported several large trees and limbs down.

Hail, Macomb

When
July 21, 4:00 PM EST
Where
Macomb County, Richmond
Measured
1 in hail
Reported by
GENERAL PUBLIC
Coordinates
42.817, -82.750

Thunderstorm Wind, Washtenaw

When
July 21, 4:10 PM EST
Where
Washtenaw County, 2 mi S of Manchester
Measured
50 kt (58 mph) estimated gust
Reported by
EMERGENCY MANAGER
Coordinates
42.117, -84.033

The emergency manager reported 4 two foot trees blown down.

Thunderstorm Wind, St. Clair

When
July 21, 4:29 PM EST
Where
St. Clair County, Marine City
Measured
52 kt (60 mph) estimated gust
Reported by
EMERGENCY MANAGER
Coordinates
42.717, -82.483

The emergency manager reported several wires down.

Hail, Lenawee

When
July 21, 4:36 PM EST
Where
Lenawee County, 5 mi E of Clinton
Measured
0.75 in hail
Reported by
GENERAL PUBLIC
Coordinates
42.067, -83.867

Thunderstorm Wind, Monroe

When
July 21, 5:09 PM EST
Where
Monroe County, Maybee
Measured
52 kt (60 mph) estimated gust
Reported by
LAW ENFORCEMENT
Coordinates
42.000, -83.517

Local law enforcement reported several trees blown down.

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Michigan in 2003Every state in 2003This day in weather historyWarnings in Michigan, July 2003

Sources

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: 5367109, 5367108, 5367117, 5367118, 5367111, 5367119, 5367110, 5367120, 5367112, 5367113, 5367115, 5367114, 5367116.