Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 42, NWS Grand Rapids, MI

August 10, 20216 counties in Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Aug 10, 2021, 9:40 PM EDT for 6 counties in Michigan. It was in force for 73 min. 12 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, 9:40 PM EDT (01:40 UTC)
Expired
Aug 10, 2021, 10:53 PM EDT
In force
73 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Allegan County, MI, Mason County, MI, Muskegon County, MI, Oceana County, MI, Ottawa County, MI, Van Buren County, MI

The radar

The Grand Rapids radar (KGRR), 45 km from the middle of the area, began a volume at 01:44 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

TimeReportWhereRemark
Aug 10, 10:01 PM EDTTSTM WND GST 521 Ene Norton Shores, MIASOS STATION KMKG MUSKEGON COUNTY AIRPORT.
Aug 10, 10:05 PM EDTTSTM WND GST 413 Ne Shelby, MIAWOS STATION C049 2 NE SHELBY.
Aug 10, 10:08 PM EDTTSTM WND GST 412 Wsw Montague, MIMESONET STATION FW0475 MONTAGUE.
Aug 10, 10:10 PM EDTTSTM WND GST 663 Ne Pentwater, MIWIND GUST AT MASON-OCEANA 911 CENTER.
Aug 10, 10:11 PM EDTTSTM WND DMGLudington, MILARGE TREE UPROOTED AND FELL ONTO FOSTER ELEMENTARY SCHOOL. POWER OUT ACROSS MUCH OF LUDINGTON.
Aug 10, 10:12 PM EDTTSTM WND GST 571 S Ludington, MIPEAK GUST AT LUDINGTON NOAA NOS WATER LEVEL MONITORING STATION 9087023 LDTM4.
Aug 10, 10:15 PM EDTTSTM WND GST 542 Ene Ludington, MIAWOS STATION KLDM LUDINGTON MASON.
Aug 10, 10:15 PM EDTTSTM WND GST 593 Ne Pentwater, MIMESONET STATION EW6978 PENTWATER.
Aug 10, 10:20 PM EDTTSTM WND DMGScottville, MIMULTIPLE LARGE LIMBS SNAPPED FROM A HEALTHY MAPLE TREE. WOOD-CONSTRUCTED BARN ALSO DAMAGED.
Aug 10, 10:24 PM EDTTSTM WND GST 501 S Ludington, MISMALL LIMBS DOWN.
Aug 10, 10:29 PM EDTTSTM WND GST 682 Ese North Dorr, MIMESONET STATION AV010 NORTH DORR.
Aug 10, 10:35 PM EDTTSTM WND DMGWayland, MI3 LARGE TREES UPROOTED AND FELL ON A HOME.

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.

IssuedProductOfficeLasted
Aug 10, 8:38 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 1.7 hours before the alert went out and 219 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 00:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2462 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 00:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 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
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.

804 
WUUS53 KGRR 110140
SVRGRR
MIC005-105-121-127-139-159-110315-
/O.NEW.KGRR.SV.W.0042.210811T0140Z-210811T0315Z/

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

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Van Buren County in southwestern Michigan...
  Allegan County in southwestern Michigan...
  Ottawa County in southwestern Michigan...
  Mason County in west central Michigan...
  Muskegon County in west central Michigan...
  Oceana County in west central Michigan...

* Until 1115 PM EDT.

* At 939 PM EDT, severe thunderstorms were located along a line 
  extending from 20 miles west of Ludington State Park to 15 miles 
  northwest of St. Joseph, moving east at 50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Muskegon...            Holland...             Grand Haven...
  Ludington...           Allegan...             South Haven...
  Paw Paw...             Hart...                Ludington SP...
  Walker...              Shelby...              Muskegon Heights...
  Hudsonville...         Zeeland...             Coopersville...
  Wayland...             Otsego...              Roosevelt Park...
  Plainwell...           North Muskegon...      

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4207 8622 4224 8622 4224 8637 4246 8625
      4270 8620 4309 8625 4362 8654 4380 8643
      4406 8651 4418 8639 4417 8604 4330 8604
      4329 8579 4277 8578 4277 8555 4242 8554
      4242 8576 4207 8576
TIME...MOT...LOC 0139Z 273DEG 45KT 4413 8687 4227 8668 

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

$$

TJT
2 follow-up statements
543 
WWUS53 KGRR 110213
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
1013 PM EDT Tue Aug 10 2021

MIC005-105-121-127-139-159-110315-
/O.CON.KGRR.SV.W.0042.000000T0000Z-210811T0315Z/
Van Buren MI-Allegan MI-Ottawa MI-Mason MI-Muskegon MI-Oceana MI-
1013 PM EDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT
FOR VAN BUREN...ALLEGAN...OTTAWA...MASON...MUSKEGON AND OCEANA
COUNTIES...

At 1013 PM EDT, severe thunderstorms were located along a line
extending from near Free Soil to near Hartford, moving east at 60
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Muskegon...            Holland...             Grand Haven...
Ludington...           Allegan...             South Haven...
Paw Paw...             Hart...                Ludington SP...
Walker...              Shelby...              Muskegon Heights...
Hudsonville...         Zeeland...             Coopersville...
Wayland...             Otsego...              Roosevelt Park...
Plainwell...           North Muskegon...      

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4207 8622 4224 8622 4224 8637 4246 8625
      4270 8620 4309 8625 4362 8654 4380 8643
      4406 8651 4418 8639 4417 8604 4330 8604
      4329 8579 4277 8578 4277 8555 4242 8554
      4242 8576 4207 8576
TIME...MOT...LOC 0213Z 274DEG 52KT 4408 8625 4222 8608 

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

$$

04
687 
WWUS53 KGRR 110253
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
1053 PM EDT Tue Aug 10 2021

MIC005-105-121-127-139-159-110303-
/O.CAN.KGRR.SV.W.0042.000000T0000Z-210811T0315Z/
Van Buren MI-Allegan MI-Ottawa MI-Mason MI-Muskegon MI-Oceana MI-
1053 PM EDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR VAN BUREN...ALLEGAN...
OTTAWA...MASON...MUSKEGON AND OCEANA COUNTIES 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 300 AM EDT for
southwestern and west central Michigan.

LAT...LON 4207 8622 4224 8622 4224 8637 4246 8625
      4270 8620 4309 8625 4362 8654 4380 8643
      4406 8651 4418 8639 4417 8604 4330 8604
      4329 8579 4277 8578 4277 8555 4242 8554
      4242 8576 4207 8576
TIME...MOT...LOC 0253Z 273DEG 45KT 4405 8556 4219 8541 

$$

04

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 8:46 PM EDTSpecial Marine WarningGRR59 min
Aug 10, 9:22 PM EDTSpecial Weather StatementGRRAllegan, Barry, Calhoun, Clare, Clinton, Eaton and 16 more3 hr
Aug 10, 10:02 PM EDTSevere Thunderstorm WarningGRRBarry, Kalamazoo, Kent, Lake, Newaygo58 min
Aug 10, 10:41 PM EDTSevere Thunderstorm WarningGRRCalhoun, Eaton, Ionia, Mecosta, Montcalm, Osceola64 min
Aug 10, 11:09 PM EDTSevere Thunderstorm WarningGRRClare, Clinton, Gratiot, Ingham, Isabella, Jackson66 min
Aug 11, 11:45 AM EDTSpecial Marine WarningGRR90 min
Aug 11, 12:40 PM EDTSpecial Weather StatementGRRKent65 min
Aug 11, 12:51 PM EDTSevere Thunderstorm WarningGRRAllegan, Ottawa28 min
Aug 11, 1:07 PM EDTSpecial Weather StatementGRRKent83 min
Aug 11, 1:28 PM EDTSpecial Weather StatementGRRCalhoun, Kalamazoo62 min
Aug 11, 1:39 PM EDTSpecial Weather StatementGRRClinton, Eaton, Gratiot, Ingham, Ionia, Jackson and 1 more2 hr
Aug 11, 1:56 PM EDTSevere Thunderstorm WarningGRRCalhoun38 min
Aug 11, 2:08 PM EDTSevere Thunderstorm WarningGRRJackson58 min
Aug 11, 2:11 PM EDTSevere Thunderstorm WarningGRRClinton, Gratiot, Ionia, Montcalm49 min
Aug 11, 2:38 PM EDTSevere Thunderstorm WarningGRRIngham34 min
Aug 11, 6:26 PM EDTSpecial Marine WarningGRR2 hr
Aug 11, 7:32 PM EDTSevere Thunderstorm WarningGRRMuskegon43 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.