Severe Thunderstorm Watch 490

Issued

Sep 7, 2021, 3:20 PM EDT (19:20 UTC)

Expired

Sep 7, 2021, 10:15 PM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

Two or more tornadoes

20%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

60%

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

90%

• Mesoscale Discussion 1705 Severe potential...watch possibleSep 7, 2:48 PM EDT
• Mesoscale Discussion 1709 Severe thunderstorm watch 490Sep 7, 5:37 PM EDT
• Mesoscale Discussion 1710 Severe thunderstorm watch 489...490Sep 7, 6:25 PM EDT
• Mesoscale Discussion 1711 Severe thunderstorm watch 490Sep 7, 8:16 PM EDT

188 
WWUS20 KWNS 071919
SEL0  
SPC WW 071919
INZ000-MIZ000-LEZ000-LHZ000-LMZ000-080300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 490
NWS Storm Prediction Center Norman OK
320 PM EDT Tue Sep 7 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northern Indiana
  Southern Lower Michigan
  Lake Erie
  Lake Huron
  Lake Michigan

* Effective this Tuesday afternoon and evening from 320 PM until
  1100 PM EDT.

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

SUMMARY...Thunderstorms will increase in coverage and intensity this
afternoon as they spread eastward across the watch area.  Damaging
winds and hail are the main threats, although there is some risk of
a tornado or two as winds aloft strengthen this evening.

The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 35 miles west southwest
of Benton Harbor MI to 40 miles north northeast of Mount Clemens MI.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU0).

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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 488...WW 489...

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 500. Mean storm motion vector
27035.

...Hart

Severe Thunderstorm Watches in Michigan, 2021Severe Thunderstorm Watches in Indiana, 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.