Alert archive / Michigan / Special Weather Statements in 2021

Special Weather Statement, NWS Grand Rapids, MI

August 8, 20214 counties in Michigan

NWS Grand Rapids, MI issued this special weather statement at Aug 8, 2021, 12:09 AM EDT for 4 counties in Michigan. It was in force for 2 hr. 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 8, 2021, 12:09 AM EDT (04:09 UTC)
Expired
Aug 8, 2021, 2:15 AM EDT
In force
2 hr
Issued by
NWS Grand Rapids, MI
Hail
0.25 in
Wind
40

Counties Kent County, MI, Mecosta County, MI, Montcalm County, MI, Newaygo County, MI

The radar

The Grand Rapids radar (KGRR), 63 km from the middle of the area, began a volume at 04:09 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 00:00Z, 4.2 hours before the alert went out and 186 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 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 519 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 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
519 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
1029 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

776 
WWUS83 KGRR 080409
SPSGRR

Special Weather Statement
National Weather Service Grand Rapids MI
1209 AM EDT Sun Aug 8 2021
 
MIZ044-045-051-057-058-080615-
Montcalm MI-Ionia MI-Mecosta MI-Newaygo MI-Kent MI-
1209 AM EDT Sun Aug 8 2021

...Strong thunderstorms will impact portions of northern Kent,
Newaygo, northern Ionia, Mecosta and Montcalm Counties through 215 AM
EDT...

At 1209 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Shelby to 9 miles northeast of Muskegon to
8 miles southwest of Grand Haven. Movement was east at 35 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Grand Rapids, Big Rapids, Greenville, Belding, Newaygo, Stanton,
White Cloud, Walker, Rockford, Sparta, Fremont, Howard City, Edmore,
Carson City, Lakeview, Hesperia, Grant, Morley, Mecosta and Canadian
Lakes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4371 8604 4382 8536 4381 8509 4347 8508
      4346 8484 4307 8484 4297 8578 4329 8579
      4330 8604
TIME...MOT...LOC 0409Z 259DEG 31KT 4360 8640 4330 8609 4298 8636 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

$$

NJJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 11:20 PM EDTSpecial Marine WarningGRR55 min
Aug 7, 11:37 PM EDTSpecial Weather StatementGRRMuskegon, Oceana, Ottawa83 min
Aug 8, 12:55 AM EDTSpecial Marine WarningGRR110 min
Aug 8, 4:05 AM EDTBeach Hazards StatementGRRMason, Muskegon, Oceana, Ottawa22 hr

Nearby

Special Weather Statements in Michigan, 2021Every special weather statement 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.