Alert archive / Michigan / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 41, NWS Detroit, MI
NWS Detroit, MI issued this severe thunderstorm warning at Jul 20, 2021, 4:57 PM EDT for Lapeer County, Michigan. It was in force for 63 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, 4:57 PM EDT (20:57 UTC)
- Expired
- Jul 20, 2021, 6:00 PM EDT
- In force
- 63 min
- Issued by
- NWS Detroit, MI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Lapeer County, MI
The radar
The Detroit radar (KDTX), 50 km from the middle of the area, began a volume at 20:58 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, 5:40 PM EDT | TSTM WND DMG | Attica, MI | TREES AND WIRES REPORTED DOWN, MOST NUMEROUS IN ATTICA TOWNSHIP. |
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, 9.0 hours before the alert went out and 46 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.
640
WUUS53 KDTX 202057
SVRDTX
MIC087-202200-
/O.NEW.KDTX.SV.W.0041.210720T2057Z-210720T2200Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
457 PM EDT Tue Jul 20 2021
The National Weather Service in Detroit/Pontiac has issued a
* Severe Thunderstorm Warning for...
Eastern Lapeer County in southeastern Michigan...
* Until 600 PM EDT.
* At 456 PM EDT, a severe thunderstorm was located over North Branch,
moving southeast at 30 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.
* This severe thunderstorm will be near...
Lum around 510 PM EDT.
Other locations in the path of this severe thunderstorm include Imlay
City, Dryden and Almont.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4289 8310 4324 8335 4327 8312 4320 8300
4289 8299
TIME...MOT...LOC 2056Z 321DEG 25KT 4319 8321
HAIL...1.00IN
WIND...60MPH
$$
AM2 follow-up statements
906
WWUS53 KDTX 202116
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
516 PM EDT Tue Jul 20 2021
MIC087-202200-
/O.CON.KDTX.SV.W.0041.000000T0000Z-210720T2200Z/
Lapeer MI-
516 PM EDT Tue Jul 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHEASTERN LAPEER COUNTY...
At 516 PM EDT, a severe thunderstorm was located over Lum, or 7 miles
south of North Branch, moving southeast at 25 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
This severe storm will be near...
Imlay City around 535 PM EDT.
Dryden around 540 PM EDT.
Almont around 555 PM EDT.
Other locations impacted by this severe thunderstorm include Kings
Mill, Attica and Goodland Township.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4315 8329 4319 8317 4320 8305 4320 8300
4289 8299 4289 8310
TIME...MOT...LOC 2116Z 322DEG 22KT 4312 8316
HAIL...<.75IN
WIND...60MPH
$$
AM607
WWUS53 KDTX 202139
SVSDTX
Severe Weather Statement
National Weather Service Detroit/Pontiac MI
539 PM EDT Tue Jul 20 2021
MIC087-202200-
/O.CON.KDTX.SV.W.0041.000000T0000Z-210720T2200Z/
Lapeer MI-
539 PM EDT Tue Jul 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHEASTERN LAPEER COUNTY...
At 539 PM EDT, a severe thunderstorm was located over Imlay City,
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.
This severe storm will be near...
Dryden around 545 PM EDT.
Almont around 555 PM EDT.
Other locations impacted by this severe thunderstorm include Attica.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4309 8325 4309 8300 4289 8299 4289 8310
TIME...MOT...LOC 2139Z 329DEG 22KT 4300 8311
HAIL...1.00IN
WIND...60MPH
$$
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, 5:59 PM EDT | Severe Thunderstorm Warning | DTX | Lapeer, Macomb, Oakland, Saint Clair | 61 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.