Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 9, NWS Grand Rapids, MI

June 18, 2021Allegan County, Kent County, Ottawa County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Jun 18, 2021, 5:45 AM EDT for Allegan County, Kent County, Ottawa County, Michigan. It was in force for 45 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
Jun 18, 2021, 5:45 AM EDT (09:45 UTC)
Expired
Jun 18, 2021, 6:30 AM EDT
In force
45 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Allegan County, MI, Kent County, MI, Ottawa County, MI

The radar

The Grand Rapids radar (KGRR), 23 km from the middle of the area, began a volume at 09:49 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
Jun 18, 6:03 AM EDTTSTM WND DMG2 E Grand Valley, MITREES AND WIRES DOWN.
Jun 18, 6:17 AM EDTTSTM WND GST 42East Grand Rapids, MIAT MEMORIAL FIELD, EAST GRAND RAPIDS HIGH SCHOOL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 9.8 hours before the alert went out and 197 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 2021-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2534 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

851 
WUUS53 KGRR 180945
SVRGRR
MIC005-081-139-181030-
/O.NEW.KGRR.SV.W.0009.210618T0945Z-210618T1030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
545 AM EDT Fri Jun 18 2021

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Northern Allegan County in southwestern Michigan...
  Southwestern Kent County in southwestern Michigan...
  Ottawa County in southwestern Michigan...

* Until 630 AM EDT.

* At 545 AM EDT, severe thunderstorms were located along a line
  extending from near Fruitport to near Saugatuck, moving southeast
  at 60 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Grand Rapids...        Holland...             Allegan...
  Wyoming...             Kentwood...            Walker...
  Grandville...          East Grand Rapids...   Hudsonville...
  Zeeland...             Coopersville...        Wayland...
  Caledonia...           Fennville...           Martin...
  Beechwood...           Jenison...             Allendale...
  Dorr...                Conklin...             

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4312 8616 4312 8591 4315 8591 4307 8551
      4277 8551 4277 8555 4247 8555 4262 8619
TIME...MOT...LOC 0945Z 297DEG 51KT 4310 8609 4267 8613 

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

NJJ
2 follow-up statements
672 
WWUS53 KGRR 181013
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
613 AM EDT Fri Jun 18 2021

MIC139-181023-
/O.CAN.KGRR.SV.W.0009.000000T0000Z-210618T1030Z/
Ottawa MI-
613 AM EDT Fri Jun 18 2021

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

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

LAT...LON 4254 8583 4277 8580 4277 8578 4313 8579
      4307 8551 4277 8551 4277 8555 4247 8555
TIME...MOT...LOC 1013Z 270DEG 51KT 4294 8565 4251 8570 

$$

MIC005-081-181030-
/O.CON.KGRR.SV.W.0009.000000T0000Z-210618T1030Z/
Allegan MI-Kent MI-
613 AM EDT Fri Jun 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 AM EDT
FOR NORTHEASTERN ALLEGAN AND SOUTHWESTERN KENT COUNTIES...

At 613 AM EDT, severe thunderstorms were located along a line
extending from near Grand Rapids to near Otsego, moving east at 60
mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Grand Rapids...        Wyoming...             Kentwood...
Walker...              Grandville...          East Grand Rapids...
Wayland...             Caledonia...           Martin...
Dorr...                Hopkins...             Dutton...
Cutlerville...         Bradley...             Belmont...
Comstock Park...       Northview...           Green Lake...
Shelbyville...         Byron Center...        

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4254 8583 4277 8580 4277 8578 4313 8579
      4307 8551 4277 8551 4277 8555 4247 8555
TIME...MOT...LOC 1013Z 270DEG 51KT 4294 8565 4251 8570 

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

NJJ
451 
WWUS53 KGRR 181025
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
625 AM EDT Fri Jun 18 2021

MIC005-081-181035-
/O.EXP.KGRR.SV.W.0009.000000T0000Z-210618T1030Z/
Allegan MI-Kent MI-
625 AM EDT Fri Jun 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ALLEGAN AND
SOUTHWESTERN KENT COUNTIES WILL EXPIRE AT 630 AM EDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 4254 8583 4277 8580 4277 8578 4313 8579
      4307 8551 4277 8551 4277 8555 4247 8555
TIME...MOT...LOC 1025Z 270DEG 51KT 4287 8545 4244 8550 

$$

NJJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 4:02 AM EDTSpecial Marine WarningGRR118 min
Jun 18, 4:44 AM EDTSpecial Weather StatementGRRAllegan, Barry, Calhoun, Clinton, Eaton, Gratiot and 9 more4 hr
Jun 18, 4:50 AM EDTSpecial Marine WarningGRR115 min
Jun 18, 4:58 AM EDTSpecial Weather StatementGRRClare, Isabella, Lake, Mecosta, Newaygo, Oceana and 1 more4 hr
Jun 18, 5:49 AM EDTSpecial Marine WarningGRR116 min
Jun 18, 6:02 AM EDTSpecial Marine WarningGRR58 min
Jun 18, 6:47 AM EDTSpecial Marine WarningGRR58 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.