Alert archive / Michigan / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 76, NWS Detroit, MI
NWS Detroit, MI issued this severe thunderstorm warning at Aug 11, 2021, 3:36 PM EDT for 4 counties in Michigan. It was in force for 69 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 11, 2021, 3:36 PM EDT (19:36 UTC)
- Expired
- Aug 11, 2021, 4:45 PM EDT
- In force
- 69 min
- Issued by
- NWS Detroit, MI
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Lapeer County, MI, Macomb County, MI, Saint Clair County, MI, Sanilac County, MI
The radar
The Detroit radar (KDTX), 59 km from the middle of the area, began a volume at 19:39 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 11, 4:00 PM EDT | TSTM WND GST 75 | 2 E Mount Clemens, MI | MEASURED AT SELFRIDGE AIR NATIONAL GUARD BASE. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 11, 2:32 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 7.6 hours before the alert went out and 55 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 106 J/kg
- Mixed-layer CIN
- -290 J/kg
- Mixed-layer LCL
- 1220 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 169 m²/s²
- 0-3 km storm-relative helicity
- 167 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
672
WUUS53 KDTX 111936
SVRDTX
MIC087-099-147-151-112045-
/O.NEW.KDTX.SV.W.0076.210811T1936Z-210811T2045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
336 PM EDT Wed Aug 11 2021
The National Weather Service in Detroit/Pontiac has issued a
* Severe Thunderstorm Warning for...
Southern Sanilac County in southeastern Michigan...
Lapeer County in southeastern Michigan...
Macomb County in southeastern Michigan...
St. Clair County in southeastern Michigan...
* Until 445 PM EDT.
* At 336 PM EDT, severe thunderstorms were located along a line
extending from near Flint to near Southfield, moving northeast at
55 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Severe thunderstorms will be near...
Warren and Hadley around 350 PM EDT.
Columbiaville, Sterling Heights and Clinton around 355 PM EDT.
St. Clair Shores, Mount Clemens, Lapeer and Macomb Township around
400 PM EDT.
Lum around 405 PM EDT.
New Baltimore and North Branch around 410 PM EDT.
Harsens Island around 415 PM EDT.
Algonac and Brown City around 420 PM EDT.
Marine City and Melvin around 425 PM EDT.
Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Goodland Township, Roseville, Shelby
Township, Lynn Township, Amador, Ray Center, Brockway and Utica.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4297 8239 4294 8245 4289 8247 4281 8248
4276 8247 4261 8252 4255 8259 4256 8264
4250 8270 4254 8276 4254 8281 4245 8284
4245 8308 4289 8310 4288 8345 4323 8346
4324 8335 4329 8335 4328 8252 4317 8250
TIME...MOT...LOC 1936Z 246DEG 48KT 4299 8368 4245 8328
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
KDK4 follow-up statements
242
WWUS53 KDTX 111951
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
351 PM EDT Wed Aug 11 2021
MIC087-099-147-151-112045-
/O.CON.KDTX.SV.W.0076.000000T0000Z-210811T2045Z/
Sanilac MI-Lapeer MI-Macomb MI-St. Clair MI-
351 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR SOUTHERN SANILAC...LAPEER...MACOMB AND ST. CLAIR COUNTIES...
At 350 PM EDT, severe thunderstorms were located along a line
extending from Columbiaville to near Oxford to Warren, moving
northeast at 50 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
These severe storms will be near...
Dryden around 355 PM EDT.
Imlay City, Romeo and Almont around 400 PM EDT.
St. Clair Shores, Mount Clemens and Macomb Township around 405 PM
EDT.
Capac and North Branch around 410 PM EDT.
New Baltimore and Emmett around 415 PM EDT.
Yale, Brown City and Harsens Island around 420 PM EDT.
Algonac around 425 PM EDT.
Marine City and Peck around 430 PM EDT.
Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Goodland Township, Roseville, Shelby
Township, Lynn Township, Amador, Ray Center, Brockway and Utica.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4297 8239 4294 8245 4289 8247 4281 8248
4276 8247 4261 8252 4255 8259 4256 8264
4250 8270 4254 8276 4254 8281 4245 8284
4245 8308 4289 8310 4288 8345 4323 8346
4324 8335 4329 8335 4328 8252 4317 8250
TIME...MOT...LOC 1950Z 242DEG 43KT 4315 8344 4287 8318 4251 8305
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
BT501
WWUS53 KDTX 111959
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
359 PM EDT Wed Aug 11 2021
MIC087-099-147-151-112045-
/O.CON.KDTX.SV.W.0076.000000T0000Z-210811T2045Z/
Sanilac MI-Lapeer MI-Macomb MI-St. Clair MI-
359 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR SOUTHERN SANILAC...LAPEER...MACOMB AND ST. CLAIR COUNTIES...
At 357 PM EDT, severe thunderstorms were located along a line
extending from near Columbiaville to Almont to near Mount Clemens,
moving northeast at 55 mph.
HAZARD...70 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to mobile
homes, roofs, and outbuildings.
These severe storms will be near...
Armada around 405 PM EDT.
New Baltimore and Capac around 410 PM EDT.
Brown City, Memphis, Emmett and Harsens Island around 415 PM EDT.
Algonac and Yale around 420 PM EDT.
Marine City and Peck around 425 PM EDT.
St. Clair around 430 PM EDT.
Lakeport around 435 PM EDT.
Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Goodland Township, Roseville, Shelby
Township, Lynn Township, Amador, Ray Center, Brockway and Utica.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These storms are capable of widespread wind damage across the area.
SEEK SHELTER NOW inside a sturdy structure and stay away from
windows.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4297 8239 4294 8245 4289 8247 4281 8248
4276 8247 4261 8252 4255 8259 4256 8264
4250 8270 4254 8276 4254 8281 4245 8284
4245 8308 4289 8310 4288 8345 4323 8346
4324 8335 4329 8335 4328 8252 4317 8250
TIME...MOT...LOC 1957Z 244DEG 48KT 4321 8333 4291 8307 4256 8291
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH
$$
BT696
WWUS53 KDTX 112021
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
421 PM EDT Wed Aug 11 2021
MIC087-099-147-151-112045-
/O.CON.KDTX.SV.W.0076.000000T0000Z-210811T2045Z/
Sanilac MI-Lapeer MI-Macomb MI-St. Clair MI-
421 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR SOUTHERN SANILAC...EASTERN LAPEER...MACOMB AND ST. CLAIR
COUNTIES...
At 419 PM EDT, severe thunderstorms were located along a line
extending from Brown City to near Emmett to near Harsens Island,
moving east at 55 mph.
THESE ARE DESTRUCTIVE STORMS FOR MACOMB AND ST CLAIR COUNTIES.
HAZARD...80 mph wind gusts.
SOURCE...Radar indicated with 75 mph observerd at Selfridge ANGB.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be heavily damaged. Expect
considerable damage to roofs, windows, and vehicles.
Extensive tree damage and power outages are likely.
These severe storms will be near...
Algonac around 425 PM EDT.
Yale and Marysville around 430 PM EDT.
Port Huron around 435 PM EDT.
Croswell around 440 PM EDT.
Lexington around 445 PM EDT.
Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Goodland Township, Lynn Township, Amador,
Ray Center, Brockway, Fort Gratiot, Avoca and Burnside.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This is a DANGEROUS SITUATION. These storms are likely producing
widespread wind damage. SEEK SHELTER NOW inside a sturdy structure
and stay away from windows.
&&
LAT...LON 4297 8239 4294 8245 4289 8247 4281 8248
4276 8247 4261 8252 4255 8259 4256 8264
4250 8270 4254 8276 4254 8281 4245 8284
4266 8299 4289 8310 4299 8317 4308 8326
4328 8305 4328 8252 4317 8250
TIME...MOT...LOC 2019Z 254DEG 48KT 4319 8300 4296 8268 4257 8253
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...80 MPH
$$
BT044
WWUS53 KDTX 112047
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
447 PM EDT Wed Aug 11 2021
MIC087-099-147-151-112055-
/O.EXP.KDTX.SV.W.0076.000000T0000Z-210811T2045Z/
Sanilac MI-Lapeer MI-Macomb MI-St. Clair MI-
447 PM EDT Wed Aug 11 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN SANILAC...EASTERN
LAPEER...MACOMB AND ST. CLAIR COUNTIES HAS EXPIRED...
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been allowed to expire. However gusty
winds and heavy rain are still possible with these thunderstorms
near the Lake Huron shoreline.
LAT...LON 4297 8239 4294 8245 4289 8247 4281 8248
4276 8247 4261 8252 4255 8259 4256 8264
4250 8270 4254 8276 4254 8281 4245 8284
4266 8299 4289 8310 4299 8317 4308 8326
4328 8305 4328 8252 4317 8250
TIME...MOT...LOC 2045Z 246DEG 48KT 4333 8257 4310 8225 4271 8210
$$
BTThe office that day
Everything else NWS Detroit, MI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 11:43 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Midland, Saginaw | 62 min |
| Aug 10, 11:53 PM EDT | Special Weather Statement | DTX | Genesee, Livingston, Shiawassee, Washtenaw | 52 min |
| Aug 10, 11:58 PM EDT | Special Marine Warning | DTX | 92 min | |
| Aug 11, 12:02 AM EDT | Severe Thunderstorm Warning | DTX | Genesee, Livingston, Oakland, Shiawassee, Washtenaw | 58 min |
| Aug 11, 12:43 AM EDT | Severe Thunderstorm Warning | DTX | Bay, Huron, Saginaw, Tuscola | 47 min |
| Aug 11, 1:09 AM EDT | Special Marine Warning | DTX | 81 min | |
| Aug 11, 1:11 AM EDT | Special Weather Statement | DTX | Huron | 49 min |
| Aug 11, 1:29 AM EDT | Special Marine Warning | DTX | 46 min | |
| Aug 11, 4:04 AM EDT | Heat Advisory | DTX | Lenawee, Livingston, Macomb, Monroe, Oakland, Washtenaw and 1 more | 13 hr |
| Aug 11, 2:22 PM EDT | Severe Thunderstorm Warning | DTX | Lenawee, Washtenaw | 68 min |
| Aug 11, 2:31 PM EDT | Severe Thunderstorm Warning | DTX | Saginaw | 42 min |
| Aug 11, 2:42 PM EDT | Severe Thunderstorm Warning | DTX | Livingston | 63 min |
| Aug 11, 2:59 PM EDT | Severe Thunderstorm Warning | DTX | Monroe, Wayne | 76 min |
| Aug 11, 3:02 PM EDT | Special Weather Statement | DTX | Genesee | 58 min |
| Aug 11, 3:09 PM EDT | Severe Thunderstorm Warning | DTX | Oakland | 66 min |
| Aug 11, 3:16 PM EDT | Severe Thunderstorm Warning | DTX | Genesee, Shiawassee | 59 min |
| Aug 11, 3:17 PM EDT | Special Marine Warning | DTX | 88 min | |
| Aug 11, 3:36 PM EDT | Special Marine Warning | DTX | 84 min |
Nearby
Severe Thunderstorm Warnings in Michigan, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.