Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 40, NWS Grand Rapids, MI

July 29, 2021Allegan County, Ottawa County, Van Buren County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Jul 29, 2021, 4:05 AM EDT for Allegan County, Ottawa County, Van Buren County, Michigan. It was in force for 55 min. 10 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
Jul 29, 2021, 4:05 AM EDT (08:05 UTC)
Expired
Jul 29, 2021, 5:00 AM EDT
In force
55 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Allegan County, MI, Ottawa County, MI, Van Buren County, MI

The radar

The Grand Rapids radar (KGRR), 57 km from the middle of the area, began a volume at 08:10 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
Jul 29, 4:12 AM EDTTSTM WND GST 58Macatawa, MIBUOY STATION HLNM4 HOLLAND HARBOR.
Jul 29, 4:20 AM EDTTSTM WND DMG1 Ene Beechwood, MILIGHT POLE BLOWN DOWN.
Jul 29, 4:21 AM EDTTSTM WND DMG2 Ese South Haven, MITREES DOWN ALONG 8TH AVENUE BETWEEN 72ND AND 68TH STREET.
Jul 29, 4:21 AM EDTTSTM WND GST 412 S Holland, MIASOS STATION KBIV W MICH REGIONAL ARPT.
Jul 29, 4:35 AM EDTTSTM WND GST 404 Sse South Haven, MIAWOS STATION KLWA SOUTH HAVEN RGNL ARPT.
Jul 29, 4:45 AM EDTTSTM WND DMG2 Sse Otsego, MITREES ACROSS ROADWAY. TIME ESTIMATED FROM RADAR.
Jul 29, 4:55 AM EDTTSTM WND GST 361 Ene Allegan, MIMESONET STATION EW9318 ALLEGAN.
Jul 29, 4:58 AM EDTTSTM WND DMG1 W Allegan, MITREES AND POWER LINES DOWN.
Jul 29, 5:04 AM EDTTSTM WND DMG2 Nw Otsego, MIWIRES DOWN.
Jul 29, 5:10 AM EDTTSTM WND GST 511 Ssw Wayland, MIMESONET STATION BDLM4 PLAINWELL.

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
Jul 29, 2:00 AM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 8.1 hours before the alert went out and 210 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 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 219 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 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.1939587897Sfc1 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
219 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

387 
WUUS53 KGRR 290805
SVRGRR
MIC005-139-159-290900-
/O.NEW.KGRR.SV.W.0040.210729T0805Z-210729T0900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
405 AM EDT Thu Jul 29 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...
  Southern Ottawa County in southwestern Michigan...

* Until 500 AM EDT.

* At 404 AM EDT, severe thunderstorms were located along a line 
  extending from 8 miles northwest of Holland to 8 miles west of 
  Stevensville, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Holland...             Allegan...             South Haven...
  Paw Paw...             Walker...              Grandville...
  Hudsonville...         Zeeland...             Wayland...
  Otsego...              Plainwell...           Hartford...
  Mattawan...            Lawton...              Bangor...
  Decatur...             Fennville...           Saugatuck...
  Martin...              Van Buren SP...        

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
      4264 8623 4270 8620 4297 8622 4296 8578
      4277 8578 4277 8555 4267 8554 4242 8563
      4242 8576 4207 8576
TIME...MOT...LOC 0804Z 277DEG 34KT 4289 8628 4204 8668 

HAIL...<.75IN
WIND...60MPH
 
$$

DUKE
2 follow-up statements
505 
WWUS53 KGRR 290823
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
423 AM EDT Thu Jul 29 2021

MIC005-139-159-290900-
/O.CON.KGRR.SV.W.0040.000000T0000Z-210729T0900Z/
Van Buren MI-Allegan MI-Ottawa MI-
423 AM EDT Thu Jul 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 AM EDT
FOR VAN BUREN...ALLEGAN AND SOUTHERN OTTAWA COUNTIES...

At 422 AM EDT, severe thunderstorms were located along a line
extending from near Zeeland to near Fennville to near Stevensville,
moving east at 50 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Public observation. At 407 AM, a mesonet station near 
         Holland reported a 61 mph wind gust.

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

Locations impacted include...
Holland...             Allegan...             South Haven...
Paw Paw...             Walker...              Grandville...
Hudsonville...         Zeeland...             Wayland...
Otsego...              Plainwell...           Hartford...
Mattawan...            Lawton...              Bangor...
Decatur...             Fennville...           Saugatuck...
Martin...              Van Buren SP...        

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
      4264 8623 4270 8620 4297 8622 4296 8578
      4277 8578 4277 8555 4267 8554 4242 8563
      4242 8576 4207 8576
TIME...MOT...LOC 0822Z 280DEG 44KT 4287 8607 4260 8604 4202 8647 

HAIL...0.75IN
WIND...60MPH
 
$$

NJJ
970 
WWUS53 KGRR 290835
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
435 AM EDT Thu Jul 29 2021

MIC139-290845-
/O.CAN.KGRR.SV.W.0040.000000T0000Z-210729T0900Z/
Ottawa MI-
435 AM EDT Thu Jul 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN OTTAWA COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 900 AM EDT for
southwestern Michigan.

LAT...LON 4207 8622 4224 8622 4224 8637 4246 8625
      4264 8623 4270 8620 4277 8620 4277 8555
      4266 8554 4242 8563 4242 8576 4207 8576
TIME...MOT...LOC 0835Z 284DEG 31KT 4275 8594 4258 8591 4215 8618 

$$

MIC005-159-290900-
/O.CON.KGRR.SV.W.0040.000000T0000Z-210729T0900Z/
Van Buren MI-Allegan MI-
435 AM EDT Thu Jul 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 AM EDT
FOR VAN BUREN AND ALLEGAN COUNTIES...

At 435 AM EDT, severe thunderstorms were located along a line
extending from 6 miles southeast of Zeeland to 5 miles northwest of
Allegan to near Hartford, moving east at 35 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Public.

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

Locations impacted include...
Holland...             Allegan...             South Haven...
Paw Paw...             Wayland...             Otsego...
Plainwell...           Hartford...            Mattawan...
Lawton...              Bangor...              Decatur...
Fennville...           Saugatuck...           Martin...
Van Buren SP...        Lake Michigan Beach... Dorr...
Pine Grove...          Covert...              

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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
      4264 8623 4270 8620 4277 8620 4277 8555
      4266 8554 4242 8563 4242 8576 4207 8576
TIME...MOT...LOC 0835Z 284DEG 31KT 4275 8594 4258 8591 4215 8618 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

NJJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 3:32 AM EDTSpecial Marine WarningGRR88 min
Jul 29, 4:47 AM EDTSevere Thunderstorm WarningGRRAllegan, Barry, Calhoun, Kalamazoo, Van Buren58 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.