Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 45, NWS Grand Rapids, MI

August 10, 20216 counties in Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Aug 10, 2021, 11:09 PM EDT for 6 counties in Michigan. It was in force for 66 min. 5 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 10, 2021, 11:09 PM EDT (03:09 UTC)
Expired: Aug 11, 2021, 12:15 AM EDT
In force: 66 min
Issued by: NWS Grand Rapids, MI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Clare County, MI, Clinton County, MI, Gratiot County, MI, Ingham County, MI, Isabella County, MI, Jackson County, MI

The radar

The Grand Rapids radar (KGRR), 78 km from the middle of the area, began a volume at 03:12 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 10, 11:50 PM EDT	TSTM WND DMG	Mount Pleasant, MI	MULTIPLE TREES DOWN AND SOME TREES BLOCKING ROADS.
Aug 10, 11:53 PM EDT	TSTM WND GST 60	3 Nne Edgemont Park, MI	ASOS STATION KLAN LANSING.
Aug 10, 11:55 PM EDT	TSTM WND DMG	1 S Mount Pleasant, MI	UPROOTED TREE ACROSS E BROOMFIELD ST NEAR CMU CAMPUS.
Aug 10, 11:55 PM EDT	TSTM WND GST 69	3 Ene Mount Pleasant, MI	AWOS STATION KMOP MT PLEASANT MUNI ARPT.
Aug 11, 12:00 AM EDT	TSTM WND DMG	2 Sw Mason, MI	4 INCH DIAMETER TREE LIMBS DOWN.

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 10, 8:38 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 3.2 hours before the alert went out and 98 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: 2462 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 207 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 3.7

Open this sounding in Storm Lab

The text

As transmitted.

775 
WUUS53 KGRR 110309
SVRGRR
MIC035-037-057-065-073-075-110415-
/O.NEW.KGRR.SV.W.0045.210811T0309Z-210811T0415Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
1109 PM EDT Tue Aug 10 2021

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Jackson County in south central Michigan...
  Ingham County in south central Michigan...
  Gratiot County in central Michigan...
  Isabella County in central Michigan...
  Clare County in central Michigan...
  Clinton County in south central Michigan...

* Until 1215 AM EDT.

* At 1108 PM EDT, severe thunderstorms were located along a line
  extending from 9 miles south of Mitchell State Park to near
  Canadian Lakes to 6 miles east of Greenville to near Nashville to 5
  miles west of Union City, moving east at 55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Lansing...             Jackson...             Mount Pleasant...
  Alma...                Mason...               St. Johns...
  Clare...               Ithaca...              East Lansing...
  St. Louis...           Williamston...         Leslie...
  Shepherd...            Breckenridge...        Stockbridge...
  Brooklyn...            Grass Lake...          Elsie...
  Farwell...             Rosebush...            

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4208 8413 4210 8471 4242 8472 4242 8460
      4277 8460 4280 8482 4346 8484 4347 8508
      4415 8508 4416 8461 4347 8462 4346 8440
      4278 8436 4277 8416
TIME...MOT...LOC 0308Z 270DEG 49KT 4410 8540 4353 8526 4320 8513 4260
8507 4207 8526

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

$$

04

1 follow-up statement

456 
WWUS53 KGRR 110407
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
1207 AM EDT Wed Aug 11 2021

MIC035-037-057-065-073-075-110417-
/O.EXP.KGRR.SV.W.0045.000000T0000Z-210811T0415Z/
Jackson MI-Ingham MI-Gratiot MI-Isabella MI-Clare MI-Clinton MI-
1207 AM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR JACKSON...INGHAM...GRATIOT...
ISABELLA...CLARE AND CLINTON COUNTIES WILL EXPIRE AT 1215 AM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 300 AM EDT for
south central and central Michigan.

LAT...LON 4208 8413 4210 8471 4242 8472 4242 8460
      4277 8460 4280 8482 4346 8484 4347 8508
      4415 8508 4416 8461 4347 8462 4346 8440
      4278 8436 4277 8416
TIME...MOT...LOC 0407Z 270DEG 49KT 4410 8434 4352 8421 4319 8409 4259
8404 4206 8423

$$

04

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 8:46 PM EDT	Special Marine Warning	GRR		59 min
Aug 10, 9:22 PM EDT	Special Weather Statement	GRR	Allegan, Barry, Calhoun, Clare, Clinton, Eaton and 16 more	3 hr
Aug 10, 9:40 PM EDT	Severe Thunderstorm Warning	GRR	Allegan, Mason, Muskegon, Oceana, Ottawa, Van Buren	73 min
Aug 10, 10:02 PM EDT	Severe Thunderstorm Warning	GRR	Barry, Kalamazoo, Kent, Lake, Newaygo	58 min
Aug 10, 10:41 PM EDT	Severe Thunderstorm Warning	GRR	Calhoun, Eaton, Ionia, Mecosta, Montcalm, Osceola	64 min
Aug 11, 11:45 AM EDT	Special Marine Warning	GRR		90 min
Aug 11, 12:40 PM EDT	Special Weather Statement	GRR	Kent	65 min
Aug 11, 12:51 PM EDT	Severe Thunderstorm Warning	GRR	Allegan, Ottawa	28 min
Aug 11, 1:07 PM EDT	Special Weather Statement	GRR	Kent	83 min
Aug 11, 1:28 PM EDT	Special Weather Statement	GRR	Calhoun, Kalamazoo	62 min
Aug 11, 1:39 PM EDT	Special Weather Statement	GRR	Clinton, Eaton, Gratiot, Ingham, Ionia, Jackson and 1 more	2 hr
Aug 11, 1:56 PM EDT	Severe Thunderstorm Warning	GRR	Calhoun	38 min
Aug 11, 2:08 PM EDT	Severe Thunderstorm Warning	GRR	Jackson	58 min
Aug 11, 2:11 PM EDT	Severe Thunderstorm Warning	GRR	Clinton, Gratiot, Ionia, Montcalm	49 min
Aug 11, 2:38 PM EDT	Severe Thunderstorm Warning	GRR	Ingham	34 min
Aug 11, 6:26 PM EDT	Special Marine Warning	GRR		2 hr
Aug 11, 7:32 PM EDT	Severe Thunderstorm Warning	GRR	Muskegon	43 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.