Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 71, NWS Grand Rapids, MI

August 28, 2021Gratiot County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Aug 28, 2021, 6:43 PM EDT for Gratiot County, Michigan. It was in force for 47 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
Aug 28, 2021, 6:43 PM EDT (22:43 UTC)
Expired
Aug 28, 2021, 7:30 PM EDT
In force
47 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Gratiot County, MI

The radar

The Grand Rapids radar (KGRR), 94 km from the middle of the area, began a volume at 22:47 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 nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 10.7 hours before the alert went out and 114 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-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1891 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 12:00Z on 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1891 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.8

Open this sounding in Storm Lab

The text

As transmitted.

575 
WUUS53 KGRR 282243
SVRGRR
MIC057-282330-
/O.NEW.KGRR.SV.W.0071.210828T2243Z-210828T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
643 PM EDT Sat Aug 28 2021

The National Weather Service in Grand Rapids has issued a

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

* Until 730 PM EDT.

* At 642 PM EDT, severe thunderstorms were located along a line
  extending from near Alma to near Ithaca, moving northeast at 15
  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.

* Locations impacted include...
  Alma...                Ithaca...              St. Louis...
  Breckenridge...        Wheeler...             North Star...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4322 8460 4336 8474 4347 8464 4347 8437
      4326 8437
TIME...MOT...LOC 2242Z 242DEG 14KT 4334 8466 4324 8455 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JC
2 follow-up statements
890 
WWUS53 KGRR 282258
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
658 PM EDT Sat Aug 28 2021

MIC057-282330-
/O.CON.KGRR.SV.W.0071.000000T0000Z-210828T2330Z/
Gratiot MI-
658 PM EDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR NORTHEASTERN GRATIOT COUNTY...

At 658 PM EDT, severe thunderstorms were located along a line
extending from near Alma to 6 miles east of Ithaca, moving northeast
at 15 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.

These severe storms will be near...
  Breckenridge around 720 PM EDT.

Other locations impacted by these severe thunderstorms include
Wheeler and North Star.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4330 8468 4335 8467 4347 8448 4347 8437
      4326 8437 4322 8460
TIME...MOT...LOC 2258Z 242DEG 14KT 4336 8460 4326 8449 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JC
469 
WWUS53 KGRR 282317
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
717 PM EDT Sat Aug 28 2021

MIC057-282330-
/O.CON.KGRR.SV.W.0071.000000T0000Z-210828T2330Z/
Gratiot MI-
717 PM EDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR EAST CENTRAL GRATIOT COUNTY...

At 717 PM EDT, severe thunderstorms were located along a line
extending from 5 miles east of Ithaca to near Marion Springs, moving
east at 20 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.

These severe thunderstorms will remain over mainly rural areas of
east central Gratiot County, including the following locations...
North Star.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4326 8464 4331 8461 4334 8457 4344 8437
      4326 8437 4322 8460
TIME...MOT...LOC 2317Z 266DEG 19KT 4331 8449 4330 8434 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 8:12 PM EDTSevere Thunderstorm WarningGRRMecosta, Newaygo48 min
Aug 28, 1:06 AM EDTSpecial Marine WarningGRR84 min
Aug 28, 2:09 AM EDTSpecial Weather StatementGRRLake, Mason66 min
Aug 28, 2:42 AM EDTAreal Flood AdvisoryGRRMason6 hr
Aug 28, 2:50 AM EDTSevere Thunderstorm WarningGRRLake, Osceola55 min
Aug 28, 3:35 AM EDTSevere Thunderstorm WarningGRRClare55 min
Aug 28, 10:32 AM EDTSmall Craft AdvisoryGRR35 hr
Aug 28, 10:40 AM EDTBeach Hazards StatementGRRAllegan, Mason, Muskegon, Oceana, Ottawa, Van Buren35 hr
Aug 28, 3:54 PM EDTSpecial Weather StatementGRRClare66 min
Aug 28, 4:07 PM EDTSpecial Weather StatementGRRMontcalm68 min
Aug 28, 5:43 PM EDTSpecial Weather StatementGRRGratiot62 min
Aug 28, 5:57 PM EDTSevere Thunderstorm WarningGRRGratiot48 min
Aug 28, 7:33 PM EDTSevere Thunderstorm WarningGRRGratiot42 min
Aug 28, 7:48 PM EDTSpecial Weather StatementGRRClinton, Ionia57 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.