Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 103, NWS Detroit, MI

August 29, 2021Macomb County, Saint Clair County, Michigan

NWS Detroit, MI issued this severe thunderstorm warning at Aug 29, 2021, 6:37 PM EDT for Macomb County, Saint Clair County, Michigan. It was in force for 83 min. 2 reports 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 29, 2021, 6:37 PM EDT (22:37 UTC)
Expired: Aug 29, 2021, 8:00 PM EDT
In force: 83 min
Issued by: NWS Detroit, MI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Macomb County, MI, Saint Clair County, MI

The radar

The Detroit radar (KDTX), 64 km from the middle of the area, began a volume at 22:39 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 29, 7:08 PM EDT	TSTM WND DMG	2 Sse Yale, MI	MULTIPLE TREES DOWN. TIME ESTIMATED BY RADAR.
Aug 29, 7:59 PM EDT	TSTM WND DMG	2 Nnw Algonac, MI	TREE DOWN NEAR MARSH RD AND HIGH RD IN CLAY TWP.

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 29, 1:46 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 10.6 hours before the alert went out and 60 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1500 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 915 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -80 m²/s²
0-3 km storm-relative helicity: -70 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

714 
WUUS53 KDTX 292237
SVRDTX
MIC099-147-300000-
/O.NEW.KDTX.SV.W.0103.210829T2237Z-210830T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
637 PM EDT Sun Aug 29 2021

The National Weather Service in Detroit/Pontiac has issued a

* Severe Thunderstorm Warning for...
  Macomb County in southeastern Michigan...
  St. Clair County in southeastern Michigan...

* Until 800 PM EDT.

* At 636 PM EDT, severe thunderstorms were located along a line
  extending from near Brown City to near Dryden to near Clarkston to
  near Novi, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Capac around 655 PM EDT.
  Romeo, Sterling Heights, Clinton and Emmett around 705 PM EDT.
  Memphis and Macomb Township around 710 PM EDT.
  Warren around 715 PM EDT.
  New Baltimore and Richmond around 725 PM EDT.
  Mount Clemens, Lakeport and Marysville around 730 PM EDT.
  St. Clair Shores and Port Huron around 735 PM EDT.
  St. Clair and Marine City around 745 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Lynn Township,
Ray Center, Brockway, Utica, Washington and Fort Gratiot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4296 8242 4289 8247 4276 8247 4261 8252
      4255 8259 4255 8265 4250 8270 4254 8276
      4254 8281 4244 8284 4245 8308 4287 8309
      4289 8309 4289 8299 4315 8300 4317 8248
      4315 8245 4307 8242
TIME...MOT...LOC 2236Z 266DEG 33KT 4325 8298 4298 8317 4270 8336 4248
8357

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Mann

6 follow-up statements

771 
WWUS53 KDTX 292252
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
652 PM EDT Sun Aug 29 2021

MIC099-147-300000-
/O.CON.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
652 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR MACOMB AND ST. CLAIR COUNTIES...

At 651 PM EDT, severe thunderstorms were located along a line
extending from near Melvin to near Capac to Rochester to near
Southfield, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Yale and Capac around 655 PM EDT.
  Romeo and Emmett around 705 PM EDT.
  Warren and Macomb Township around 710 PM EDT.
  Armada around 715 PM EDT.
  New Baltimore, Richmond and Clinton around 725 PM EDT.
  St. Clair Shores, Port Huron, Mount Clemens and Lakeport around 
  730 PM EDT.
  St. Clair around 745 PM EDT.
  Marysville around 750 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Lynn Township,
Ray Center, Brockway, Utica, Washington and Fort Gratiot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4296 8242 4289 8247 4276 8247 4261 8252
      4255 8259 4255 8265 4250 8270 4254 8276
      4254 8281 4244 8284 4245 8308 4287 8309
      4289 8309 4289 8299 4315 8300 4317 8248
      4315 8245 4307 8242
TIME...MOT...LOC 2251Z 257DEG 33KT 4321 8281 4298 8295 4270 8314 4249
8333

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

828 
WWUS53 KDTX 292301 RRA
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
701 PM EDT Sun Aug 29 2021

MIC099-147-300000-
/O.CON.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
701 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR MACOMB AND ST. CLAIR COUNTIES...

At 701 PM EDT, severe thunderstorms were located along a line
extending from near Yale to near Capac to near Rochester to
Southfield, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Yale, Capac and Memphis around 705 PM EDT.
  Emmett around 710 PM EDT.
  New Baltimore and Richmond around 725 PM EDT.
  St. Clair Shores and Mount Clemens around 730 PM EDT.
  Port Huron and Lakeport around 735 PM EDT.
  Marine City around 745 PM EDT.
  St. Clair and Marysville around 750 PM EDT.
  Harsens Island around 755 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Lynn Township,
Ray Center, Brockway, Utica, Washington and Fort Gratiot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Detroit/Pontiac.

&&

LAT...LON 4296 8242 4289 8247 4276 8247 4261 8252
      4255 8259 4255 8265 4250 8270 4254 8276
      4254 8281 4244 8284 4245 8308 4287 8309
      4289 8309 4289 8299 4315 8300 4317 8248
      4315 8245 4307 8242
TIME...MOT...LOC 2301Z 257DEG 33KT 4316 8274 4298 8286 4270 8305 4249
8324

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

396 
WWUS53 KDTX 292321 RRA
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
721 PM EDT Sun Aug 29 2021

MIC099-147-300000-
/O.CON.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
721 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR MACOMB AND ST. CLAIR COUNTIES...

At 721 PM EDT, severe thunderstorms were located along a line
extending from near Lakeport to near Marysville to New Baltimore to
near St. Clair Shores, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Lakeport around 725 PM EDT.
  Marysville around 730 PM EDT.
  Port Huron around 735 PM EDT.
  Algonac around 740 PM EDT.
  St. Clair and Marine City around 745 PM EDT.
  Harsens Island around 755 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Lynn Township,
Ray Center, Brockway, Utica, Washington and Fort Gratiot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Detroit/Pontiac.

&&

LAT...LON 4296 8242 4289 8247 4276 8247 4261 8252
      4255 8259 4255 8265 4250 8270 4254 8276
      4254 8281 4244 8284 4245 8308 4287 8309
      4289 8309 4289 8299 4315 8300 4317 8248
      4315 8245 4307 8242
TIME...MOT...LOC 2321Z 257DEG 33KT 4313 8245 4295 8257 4267 8276 4246
8295

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

918 
WWUS53 KDTX 292332
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
732 PM EDT Sun Aug 29 2021

MIC099-147-300000-
/O.CON.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
732 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR MACOMB AND ST. CLAIR COUNTIES...

At 732 PM EDT, severe thunderstorms were located along a line
extending from near Lakeport to near Marysville to near New Baltimore
to St. Clair Shores, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  St. Clair, Algonac, Lakeport and Marysville around 740 PM EDT.
  Port Huron and Marine City around 745 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Lynn Township,
Ray Center, Brockway, Utica, Washington and Fort Gratiot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Detroit/Pontiac.

&&

LAT...LON 4296 8242 4289 8247 4276 8247 4261 8252
      4255 8259 4255 8265 4250 8270 4254 8276
      4254 8281 4244 8284 4245 8308 4287 8309
      4289 8309 4289 8299 4315 8300 4317 8248
      4315 8245 4307 8242
TIME...MOT...LOC 2332Z 257DEG 33KT 4307 8249 4290 8257 4268 8263 4247
8290

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

994 
WWUS53 KDTX 292340
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
740 PM EDT Sun Aug 29 2021

MIC099-147-300000-
/O.CON.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
740 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR MACOMB AND ST. CLAIR COUNTIES...

At 739 PM EDT, severe thunderstorms were located along a line
extending from near Lakeport to Marysville to near Marine City to
near St. Clair Shores, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Port Huron, St. Clair, Lakeport, Marysville and Marine City around 
  745 PM EDT.

Other locations impacted by these severe thunderstorms include
Anchorville, North Street, Roseville, Shelby Township, Ray Center,
Utica, Fort Gratiot, Avoca, Grosse Pointe Shores and Center Line.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Detroit/Pontiac.

&&

LAT...LON 4289 8247 4276 8247 4261 8252 4255 8259
      4255 8266 4250 8270 4254 8276 4254 8281
      4244 8284 4245 8308 4267 8308 4317 8265
      4317 8248 4307 8242 4296 8242
TIME...MOT...LOC 2339Z 266DEG 33KT 4307 8243 4290 8251 4268 8257 4247
8284

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

872 
WWUS53 KDTX 292359
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
759 PM EDT Sun Aug 29 2021

MIC099-147-300009-
/O.EXP.KDTX.SV.W.0103.000000T0000Z-210830T0000Z/
Macomb MI-St. Clair MI-
759 PM EDT Sun Aug 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR MACOMB AND ST. CLAIR COUNTIES
WILL EXPIRE AT 800 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

LAT...LON 4289 8247 4276 8247 4261 8252 4255 8259
      4255 8266 4250 8270 4254 8276 4254 8281
      4244 8284 4245 8308 4267 8308 4317 8265
      4317 8248 4307 8242 4296 8242
TIME...MOT...LOC 2359Z 266DEG 33KT 4308 8218 4291 8226 4269 8232 4248
8260

$$

Behnke

The office that day

Everything else NWS Detroit, MI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 8:18 PM EDT	Special Weather Statement	DTX	Saginaw	72 min
Aug 28, 8:22 PM EDT	Special Weather Statement	DTX	Saint Clair, Sanilac	68 min
Aug 28, 10:00 PM EDT	Severe Thunderstorm Warning	DTX	Shiawassee	20 min
Aug 28, 10:17 PM EDT	Special Weather Statement	DTX	Genesee	28 min
Aug 29, 1:53 AM EDT	Special Weather Statement	DTX	Bay, Midland	67 min
Aug 29, 2:16 AM EDT	Severe Thunderstorm Warning	DTX	Bay, Midland	44 min
Aug 29, 2:32 AM EDT	Special Marine Warning	DTX		42 min
Aug 29, 3:40 PM EDT	Special Weather Statement	DTX	Bay, Midland	65 min
Aug 29, 3:54 PM EDT	Special Marine Warning	DTX		108 min
Aug 29, 4:07 PM EDT	Special Weather Statement	DTX	Saginaw, Shiawassee	83 min
Aug 29, 4:30 PM EDT	Severe Thunderstorm Warning	DTX	Saginaw, Shiawassee	75 min
Aug 29, 4:38 PM EDT	Special Weather Statement	DTX	Huron	67 min
Aug 29, 4:58 PM EDT	Severe Thunderstorm Warning	DTX	Huron	62 min
Aug 29, 5:11 PM EDT	Severe Thunderstorm Warning	DTX	Bay, Genesee, Tuscola	79 min
Aug 29, 5:25 PM EDT	Severe Thunderstorm Warning	DTX	Livingston	65 min
Aug 29, 5:32 PM EDT	Special Marine Warning	DTX		118 min
Aug 29, 5:56 PM EDT	Severe Thunderstorm Warning	DTX	Oakland	64 min
Aug 29, 5:58 PM EDT	Severe Thunderstorm Warning	DTX	Lapeer	62 min
Aug 29, 6:00 PM EDT	Severe Thunderstorm Warning	DTX	Huron	59 min
Aug 29, 6:13 PM EDT	Severe Thunderstorm Warning	DTX	Sanilac	77 min
Aug 29, 6:45 PM EDT	Severe Thunderstorm Warning	DTX	Lenawee	75 min
Aug 29, 6:51 PM EDT	Special Marine Warning	DTX		114 min
Aug 29, 7:00 PM EDT	Severe Thunderstorm Warning	DTX	Washtenaw	57 min
Aug 29, 7:23 PM EDT	Special Weather Statement	DTX	Monroe	67 min
Aug 29, 7:29 PM EDT	Special Weather Statement	DTX	Wayne	61 min
Aug 29, 7:30 PM EDT	Special Marine Warning	DTX		68 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2021 Every 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.