Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 47, NWS Grand Rapids, MI

August 11, 2021Calhoun County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Aug 11, 2021, 1:56 PM EDT for Calhoun County, Michigan. It was in force for 38 min. 2 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 11, 2021, 1:56 PM EDT (17:56 UTC)
Expired: Aug 11, 2021, 2:34 PM EDT
In force: 38 min
Issued by: NWS Grand Rapids, MI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Calhoun County, MI

The radar

The Grand Rapids radar (KGRR), 82 km from the middle of the area, began a volume at 17:58 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
Aug 11, 2:06 PM EDT	TSTM WND GST 60	2 Se Brownlee Park, MI	WATTLES RD AND CROSBY DR.
Aug 11, 2:15 PM EDT	TSTM WND GST 41	2 Sse Marshall, MI	AWOS STATION KRMY MARSHALL BROOKS FIELD.

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 11, 11:50 AM EDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 5.9 hours before the alert went out and 136 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: 106 J/kg
Mixed-layer CIN: -290 J/kg
Mixed-layer LCL: 1220 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 169 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

504 
WUUS53 KGRR 111756
SVRGRR
MIC025-111900-
/O.NEW.KGRR.SV.W.0047.210811T1756Z-210811T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
156 PM EDT Wed Aug 11 2021

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Calhoun County in south central Michigan...

* Until 300 PM EDT.

* At 155 PM EDT, a severe thunderstorm was located over Burlington,
  or 11 miles north of Coldwater, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Marshall around 215 PM EDT.

Other locations in the path of this severe thunderstorm include Homer
and Albion.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4242 8508 4242 8472 4207 8471 4208 8529
TIME...MOT...LOC 1755Z 236DEG 26KT 4210 8506 

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

$$

LAURENS

2 follow-up statements

681 
WWUS53 KGRR 111824
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
224 PM EDT Wed Aug 11 2021

MIC025-111900-
/O.CON.KGRR.SV.W.0047.000000T0000Z-210811T1900Z/
Calhoun MI-
224 PM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR EASTERN CALHOUN COUNTY...

At 223 PM EDT, severe thunderstorms were located along a line
extending from Albion to near Tekonsha, moving northeast at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Albion...              Homer...               Marengo...
Tekonsha...            

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4240 8477 4242 8472 4207 8471 4208 8505
TIME...MOT...LOC 1823Z 234DEG 33KT 4224 8475 4210 8499 

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

$$

MEADE

613 
WWUS53 KGRR 111834
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
234 PM EDT Wed Aug 11 2021

MIC025-111844-
/O.CAN.KGRR.SV.W.0047.000000T0000Z-210811T1900Z/
Calhoun MI-
234 PM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CALHOUN COUNTY IS
CANCELLED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 500 PM EDT for
south central Michigan.

LAT...LON 4240 8477 4242 8472 4207 8471 4208 8505
TIME...MOT...LOC 1834Z 236DEG 26KT 4228 8466 4214 8490 

$$

MEADE

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 10, 11:09 PM EDT	Severe Thunderstorm Warning	GRR	Clare, Clinton, Gratiot, Ingham, Isabella, Jackson	66 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, 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.