Alert archive / Michigan / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 12, NWS Grand Rapids, MI
NWS Grand Rapids, MI issued this severe thunderstorm warning at Jun 20, 2021, 8:42 PM EDT for 4 counties in Michigan. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2021, 8:42 PM EDT (00:42 UTC)
- Expired
- Jun 20, 2021, 9:45 PM EDT
- In force
- 63 min
- Issued by
- NWS Grand Rapids, MI
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Calhoun County, MI, Eaton County, MI, Ingham County, MI, Jackson County, MI
The radar
The Grand Rapids radar (KGRR), 91 km from the middle of the area, began a volume at 00:46 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 20, 6:06 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Detroit, MI (KDTX), launched 00:00Z, 0.7 hours before the alert went out and 111 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
- 133 J/kg
- Mixed-layer CIN
- -112 J/kg
- Mixed-layer LCL
- 1501 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
179
WUUS53 KGRR 210042
SVRGRR
MIC025-045-065-075-210145-
/O.NEW.KGRR.SV.W.0012.210621T0042Z-210621T0145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
842 PM EDT Sun Jun 20 2021
The National Weather Service in Grand Rapids has issued a
* Severe Thunderstorm Warning for...
Northeastern Calhoun County in south central Michigan...
Jackson County in south central Michigan...
Ingham County in south central Michigan...
Eaton County in south central Michigan...
* Until 945 PM EDT.
* At 841 PM EDT, severe thunderstorms were located along a line
extending from near Brownlee Park to 5 miles east of Marshall to
near Litchfield, moving northeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Lansing... Jackson... Charlotte...
Albion... Mason... Marshall...
Battle Creek... Eaton Rapids... East Lansing...
Grand Ledge... Williamston... Potterville...
Leslie... Homer... Bellevue...
Stockbridge... Brooklyn... Grass Lake...
Brownlee Park... Edgemont Park...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Large hail and damaging winds and continuous cloud to ground
lightning is occurring with these storms. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.
&&
LAT...LON 4207 8414 4207 8490 4219 8495 4232 8521
4242 8512 4242 8507 4247 8507 4276 8482
4277 8416 4242 8413
TIME...MOT...LOC 0041Z 231DEG 41KT 4237 8510 4224 8486 4208 8478
HAIL...0.75IN
WIND...60MPH
$$
DUKE2 follow-up statements
000
WWUS53 KGRR 210113
SVSGRR
Severe Weather Statement
National Weather Service Grand Rapids MI
913 PM EDT Sun Jun 20 2021
MIC025-210123-
/O.CAN.KGRR.SV.W.0012.000000T0000Z-210621T0145Z/
Calhoun MI-
913 PM EDT Sun Jun 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CALHOUN COUNTY IS
CANCELLED...
The storms which prompted the warning have weakened and moved out of
the warned area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
south central Michigan.
LAT...LON 4207 8414 4208 8471 4242 8472 4242 8474
4275 8473 4277 8416 4245 8414 4242 8413
TIME...MOT...LOC 0113Z 231DEG 41KT 4260 8472 4247 8448 4231 8440
$$
MIC045-065-075-210145-
/O.CON.KGRR.SV.W.0012.000000T0000Z-210621T0145Z/
Jackson MI-Ingham MI-Eaton MI-
913 PM EDT Sun Jun 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR JACKSON...INGHAM AND EASTERN EATON COUNTIES...
At 913 PM EDT, severe thunderstorms were located along a line
extending from near Potterville to near Leslie to near Jackson,
moving northeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Lansing... Jackson... Mason...
Eaton Rapids... East Lansing... Grand Ledge...
Williamston... Potterville... Leslie...
Stockbridge... Brooklyn... Grass Lake...
Edgemont Park... Vandercook Lake... Leoni...
Spring Arbor... Napoleon... Sandstone...
Aurelius... Onondaga...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 4207 8414 4208 8471 4242 8472 4242 8474
4275 8473 4277 8416 4245 8414 4242 8413
TIME...MOT...LOC 0113Z 231DEG 41KT 4260 8472 4247 8448 4231 8440
HAIL...0.75IN
WIND...60MPH
$$
04437
WWUS53 KGRR 210141
SVSGRR
Severe Weather Statement
National Weather Service Grand Rapids MI
941 PM EDT Sun Jun 20 2021
MIC045-065-075-210150-
/O.EXP.KGRR.SV.W.0012.000000T0000Z-210621T0145Z/
Jackson MI-Ingham MI-Eaton MI-
941 PM EDT Sun Jun 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR JACKSON...INGHAM AND EASTERN
EATON COUNTIES WILL EXPIRE AT 945 PM EDT...
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
south central Michigan.
LAT...LON 4207 8414 4208 8471 4242 8472 4242 8474
4275 8473 4277 8416 4245 8414 4242 8413
TIME...MOT...LOC 0140Z 231DEG 41KT 4276 8445 4263 8421 4247 8413
$$
04The office that day
Everything else NWS Grand Rapids, MI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 10:39 PM EDT | Areal Flood Advisory | GRR | Allegan, Calhoun, Jackson, Kalamazoo, Van Buren | 6 hr |
| Jun 21, 12:38 AM EDT | Severe Thunderstorm Warning | GRR | Van Buren | 67 min |
| Jun 21, 12:45 AM EDT | Special Marine Warning | GRR | 31 min | |
| Jun 21, 1:12 AM EDT | Tornado Warning | GRR | Van Buren | 36 min |
| Jun 21, 1:30 AM EDT | Severe Thunderstorm Warning | GRR | Kalamazoo | 60 min |
| Jun 21, 1:33 AM EDT | Severe Thunderstorm Warning | GRR | Calhoun | 57 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.