Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 95, NWS Grand Rapids, MI

September 12, 2021Gratiot County, Montcalm County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Sep 12, 2021, 7:16 PM EDT for Gratiot County, Montcalm County, Michigan. It was in force for 45 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: Sep 12, 2021, 7:16 PM EDT (23:16 UTC)
Expired: Sep 12, 2021, 8:01 PM EDT
In force: 45 min
Issued by: NWS Grand Rapids, MI
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Gratiot County, MI, Montcalm County, MI

The radar

The Grand Rapids radar (KGRR), 77 km from the middle of the area, began a volume at 23:17 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
Sep 12, 7:22 PM EDT	HAIL 1	1 Ne Westville, MI	FROM SOCIAL MEDIA.

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
Sep 12, 5:15 PM EDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 11.3 hours before the alert went out and 133 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: 677 J/kg
Mixed-layer CIN: -369 J/kg
Mixed-layer LCL: 734 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 299 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

100 
WUUS53 KGRR 122316
SVRGRR
MIC057-117-130015-
/O.NEW.KGRR.SV.W.0095.210912T2316Z-210913T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
716 PM EDT Sun Sep 12 2021

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Gratiot County in central Michigan...
  Northeastern Montcalm County in central Michigan...

* Until 815 PM EDT.

* At 715 PM EDT, a severe thunderstorm was located over Edmore, or 6
  miles north of Stanton, moving east at 50 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Alma and St. Louis around 740 PM EDT.
  Ithaca around 745 PM EDT.
  Breckenridge around 750 PM EDT.

Other locations impacted by this severe thunderstorm include McBride,
Westville, Elm Hall, Cedar Lake, North Star, Vestaburg, Forest Hill,
Sumner, Riverdale and Ashley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4331 8516 4347 8510 4347 8437 4316 8437
TIME...MOT...LOC 2315Z 276DEG 44KT 4339 8506 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

CAS

2 follow-up statements

112 
WWUS53 KGRR 122334
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
734 PM EDT Sun Sep 12 2021

MIC117-122342-
/O.CAN.KGRR.SV.W.0095.000000T0000Z-210913T0015Z/
Montcalm MI-
734 PM EDT Sun Sep 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MONTCALM COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the area. Therefore, the warning has been cancelled for Montcalm 
County. Other storms in Montcalm County continue to produce 
dangerous lightning.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central Michigan.

LAT...LON 4322 8437 4327 8484 4346 8484 4345 8437
TIME...MOT...LOC 2332Z 276DEG 44KT 4337 8476 

$$

MIC057-130015-
/O.CON.KGRR.SV.W.0095.000000T0000Z-210913T0015Z/
Gratiot MI-
734 PM EDT Sun Sep 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR GRATIOT COUNTY...

At 733 PM EDT, a severe thunderstorm was located near Alma, moving 
east at 50 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
  St. Louis, Ithaca and Breckenridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4322 8437 4327 8484 4346 8484 4345 8437
TIME...MOT...LOC 2332Z 276DEG 44KT 4337 8476 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

CAS

976 
WWUS53 KGRR 130001
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
801 PM EDT Sun Sep 12 2021

MIC057-130010-
/O.CAN.KGRR.SV.W.0095.000000T0000Z-210913T0015Z/
Gratiot MI-
801 PM EDT Sun Sep 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR GRATIOT COUNTY IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.  However, lightning is
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central Michigan.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Grand Rapids.

LAT...LON 4322 8437 4327 8484 4346 8484 4345 8437
TIME...MOT...LOC 2357Z 276DEG 44KT 4333 8428 

$$

CAS

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 12, 6:01 AM EDT	Small Craft Advisory	GRR		10 hr
Sep 12, 6:03 AM EDT	Beach Hazards Statement	GRR	Allegan, Ottawa, Van Buren	10 hr
Sep 12, 2:29 PM EDT	Special Marine Warning	GRR		61 min
Sep 12, 2:42 PM EDT	Special Weather Statement	GRR	Lake, Mason, Newaygo, Oceana	63 min
Sep 12, 3:50 PM EDT	Special Weather Statement	GRR	Isabella, Mecosta	40 min
Sep 12, 4:29 PM EDT	Special Weather Statement	GRR	Isabella	31 min
Sep 12, 4:56 PM EDT	Severe Thunderstorm Warning	GRR	Gratiot	34 min
Sep 12, 5:31 PM EDT	Special Marine Warning	GRR		82 min
Sep 12, 6:22 PM EDT	Special Weather Statement	GRR	Muskegon, Ottawa	53 min
Sep 12, 6:40 PM EDT	Severe Thunderstorm Warning	GRR	Muskegon, Ottawa	35 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.