Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Grand Rapids, MI

August 28, 2021Gratiot County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Aug 28, 2021, 7:33 PM EDT for Gratiot County, Michigan. It was in force for 42 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, 7:33 PM EDT (23:33 UTC)
Expired
Aug 28, 2021, 8:15 PM EDT
In force
42 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), 97 km from the middle of the area, began a volume at 23:35 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, 11.6 hours before the alert went out and 99 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.

459 
WUUS53 KGRR 282333
SVRGRR
MIC057-290015-
/O.NEW.KGRR.SV.W.0072.210828T2333Z-210829T0015Z/

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

The National Weather Service in Grand Rapids has issued a

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

* Until 815 PM EDT.

* At 732 PM EDT, severe thunderstorms were located along a line
  extending from 5 miles south of Breckenridge to 6 miles northwest
  of Elsie, moving northeast at 35 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...
  Ashley...              Bannister...           

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 4312 8450 4325 8452 4332 8454 4334 8451
      4335 8437 4321 8437 4321 8436 4320 8436
      4312 8437
TIME...MOT...LOC 2332Z 222DEG 30KT 4333 8445 4318 8445 

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

$$

JC
1 follow-up statement
482 
WWUS53 KGRR 290007
SVSGRR

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

MIC057-290015-
/O.CON.KGRR.SV.W.0072.000000T0000Z-210829T0015Z/
Gratiot MI-
807 PM EDT Sat Aug 28 2021

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

At 807 PM EDT, severe thunderstorms were located along a line
extending from 5 miles west of Freeland to 5 miles northwest of St.
Charles, moving northeast at 35 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...
Ashley...              Bannister...           

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 4324 8452 4332 8437 4321 8437 4321 8436
      4320 8436 4312 8437 4312 8450
TIME...MOT...LOC 0007Z 222DEG 30KT 4352 8421 4337 8422 

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, 6:43 PM EDTSevere Thunderstorm WarningGRRGratiot47 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.