Alert archive / Michigan / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 42, NWS Detroit, MI
NWS Detroit, MI issued this severe thunderstorm warning at Jul 20, 2021, 5:59 PM EDT for 4 counties in Michigan. It was in force for 61 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
- Jul 20, 2021, 5:59 PM EDT (21:59 UTC)
- Expired
- Jul 20, 2021, 7:00 PM EDT
- In force
- 61 min
- Issued by
- NWS Detroit, MI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Lapeer County, MI, Macomb County, MI, Oakland County, MI, Saint Clair County, MI
The radar
The Detroit radar (KDTX), 46 km from the middle of the area, began a volume at 22:01 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 |
|---|---|---|---|
| Jul 20, 6:23 PM EDT | TSTM WND GST 60 | Oxford, MI | A TRAINED SPOTTER ESTIMATED 60 MPH WINDS AND REPORTED PEA SIZE HAIL. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 10.0 hours before the alert went out and 42 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
- 151 J/kg
- Mixed-layer CIN
- -120 J/kg
- Mixed-layer LCL
- 1105 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 16 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
063
WUUS53 KDTX 202159
SVRDTX
MIC087-099-125-147-202300-
/O.NEW.KDTX.SV.W.0042.210720T2159Z-210720T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
559 PM EDT Tue Jul 20 2021
The National Weather Service in Detroit/Pontiac has issued a
* Severe Thunderstorm Warning for...
Southern Lapeer County in southeastern Michigan...
Northeastern Oakland County in southeastern Michigan...
Northern Macomb County in southeastern Michigan...
West central St. Clair County in southeastern Michigan...
* Until 700 PM EDT.
* At 559 PM EDT, a severe thunderstorm was located over Almont,
moving southeast at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Romeo, Armada and New Baltimore.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4269 8272 4269 8330 4302 8342 4302 8300
4301 8299 4296 8290 4290 8286 4281 8273
TIME...MOT...LOC 2159Z 322DEG 21KT 4291 8309
HAIL...1.00IN
WIND...60MPH
$$
AM3 follow-up statements
977
WWUS53 KDTX 202218
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
618 PM EDT Tue Jul 20 2021
MIC087-147-202228-
/O.CAN.KDTX.SV.W.0042.000000T0000Z-210720T2300Z/
Lapeer MI-St. Clair MI-
618 PM EDT Tue Jul 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN LAPEER AND WEST
CENTRAL ST. CLAIR COUNTIES IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4269 8272 4269 8330 4288 8337 4289 8285
4281 8273
TIME...MOT...LOC 2218Z 334DEG 22KT 4283 8324
$$
MIC099-125-202300-
/O.CON.KDTX.SV.W.0042.000000T0000Z-210720T2300Z/
Oakland MI-Macomb MI-
618 PM EDT Tue Jul 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHEASTERN OAKLAND AND NORTHERN MACOMB COUNTIES...
At 618 PM EDT, a severe thunderstorm was located over Oxford, moving
southeast at 25 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Pontiac, New Baltimore, Richmond, Romeo, Oxford, Rochester, Armada,
Rochester Hills, Auburn Hills, New Haven, Lake Orion, Washington,
Leonard, Lakeville, Ray Center and Stoney Creek Metro Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4269 8272 4269 8330 4288 8337 4289 8285
4281 8273
TIME...MOT...LOC 2218Z 334DEG 22KT 4283 8324
HAIL...<.75IN
WIND...60MPH
$$
AM830
WWUS53 KDTX 202233
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
633 PM EDT Tue Jul 20 2021
MIC099-125-202300-
/O.CON.KDTX.SV.W.0042.000000T0000Z-210720T2300Z/
Oakland MI-Macomb MI-
633 PM EDT Tue Jul 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHEASTERN OAKLAND AND NORTHWESTERN MACOMB COUNTIES...
At 633 PM EDT, a severe thunderstorm was located near Rochester, or
near Oxford, moving southeast at 25 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Pontiac, Romeo, Oxford, Rochester, Rochester Hills, Auburn Hills,
Lake Orion, Washington and Stoney Creek Metro Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4281 8334 4282 8297 4275 8291 4269 8285
4269 8330
TIME...MOT...LOC 2233Z 326DEG 21KT 4276 8318
HAIL...<.75IN
WIND...60MPH
$$
AM471
WWUS53 KDTX 202253
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
653 PM EDT Tue Jul 20 2021
MIC099-125-202302-
/O.EXP.KDTX.SV.W.0042.000000T0000Z-210720T2300Z/
Oakland MI-Macomb MI-
653 PM EDT Tue Jul 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN OAKLAND AND
NORTHWESTERN MACOMB COUNTIES WILL EXPIRE AT 700 PM EDT...
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.
Remember, a Severe Thunderstorm Warning still remains in effect for
Southeast Oakland County and Southern Macomb County until 745 EDT.
LAT...LON 4281 8334 4282 8297 4275 8291 4269 8285
4269 8330
TIME...MOT...LOC 2252Z 322DEG 21KT 4268 8309
$$
AMThe office that day
Everything else NWS Detroit, MI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 9:54 PM EDT | Small Craft Advisory | DTX | 42 hr | |
| Jul 19, 9:59 PM EDT | Beach Hazards Statement | DTX | Bay, Huron, Saint Clair, Sanilac | 26 hr |
| Jul 20, 2:19 PM EDT | Special Marine Warning | DTX | 73 min | |
| Jul 20, 2:29 PM EDT | Special Weather Statement | DTX | Huron | 91 min |
| Jul 20, 2:57 PM EDT | Severe Thunderstorm Warning | DTX | Huron | 51 min |
| Jul 20, 3:06 PM EDT | Special Marine Warning | DTX | 84 min | |
| Jul 20, 3:35 PM EDT | Special Weather Statement | DTX | Sanilac | 55 min |
| Jul 20, 4:27 PM EDT | Special Weather Statement | DTX | Lapeer | 93 min |
| Jul 20, 4:57 PM EDT | Severe Thunderstorm Warning | DTX | Lapeer | 63 min |
| Jul 20, 6:43 PM EDT | Severe Thunderstorm Warning | DTX | Macomb, Oakland | 62 min |
| Jul 20, 6:59 PM EDT | Special Weather Statement | DTX | Livingston, Oakland | 61 min |
| Jul 20, 7:28 PM EDT | Severe Thunderstorm Warning | DTX | Oakland, Wayne | 62 min |
| Jul 20, 7:53 PM EDT | Special Weather Statement | DTX | Washtenaw | 97 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.