Severe Thunderstorm Watch 488

Issued

Sep 7, 2021, 12:21 PM EDT (16:21 UTC)

Expired

Sep 7, 2021, 6:47 PM EDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Green Bay radar (KGRB), 133 km from the middle of the area, began a volume at 16:25 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.

Two or more tornadoes

10%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1701 Severe potential...watch unlikelySep 7, 10:15 AM EDT
• Mesoscale Discussion 1702 Severe potential...watch possibleSep 7, 11:47 AM EDT
• Mesoscale Discussion 1704 Severe thunderstorm watch 488Sep 7, 1:49 PM EDT
• Mesoscale Discussion 1709 Severe thunderstorm watch 490Sep 7, 5:37 PM EDT

435 
WWUS20 KWNS 071618
SEL8  
SPC WW 071618
MIZ000-WIZ000-LHZ000-LMZ000-072300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 488
NWS Storm Prediction Center Norman OK
1120 AM CDT Tue Sep 7 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Central Lower Michigan
  Southeast Wisconsin
  Lake Huron
  Lake Michigan

* Effective this Tuesday morning and evening from 1120 AM until
  600 PM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...A band of thunderstorms will sag southward across the
watch area this afternoon, posing a risk of locally damaging wind
gusts and hail.

The severe thunderstorm watch area is approximately along and 35
statute miles north and south of a line from 30 miles north
northwest of Janesville WI to 60 miles east of Houghton Lake MI. For
a complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
24040.

...Hart

Severe Thunderstorm Watches in Michigan, 2021Severe Thunderstorm Watches in Wisconsin, 2021Every severe thunderstorm watch in 2021

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.