Severe Thunderstorm Watch 430

Issued

Jul 21, 2017, 7:34 PM CDT (00:34 UTC)

Expired

Jul 22, 2017, 2:00 AM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Minneapolis radar (KMPX), 141 km from the middle of the area, began a volume at 00:36 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

5%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1384Jul 21, 6:25 PM CDT
• Mesoscale Discussion 1389Jul 21, 10:34 PM CDT

443 
WWUS20 KWNS 220031
SEL0  
SPC WW 220031
MNZ000-SDZ000-WIZ000-LSZ000-220700-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 430
NWS Storm Prediction Center Norman OK
735 PM CDT Fri Jul 21 2017

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  South-central Minnesota
  Eastern South Dakota
  Northwest Wisconsin
  Lake Superior

* Effective this Friday night and Saturday morning from 735 PM
  until 200 AM CDT.

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

SUMMARY...A relatively fast-moving line of storms across
north-central/northeast Minnesota early this evening will continue
southeastward into northwest Wisconsin and east-central Minnesota,
while additional storms will continue to develop within a moderately
unstable air mass across eastern South Dakota into west-central
Minnesota. Damaging winds and some severe hail are the main
concerns.

The severe thunderstorm watch area is approximately along and 30
statute miles north and south of a line from 20 miles west of
Watertown SD to 145 miles east northeast of Saint Cloud MN. 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 428...WW 429...

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 550. Mean storm motion vector
31035.

...Guyer

Severe Thunderstorm Watches in Minnesota, 2017Severe Thunderstorm Watches in Wisconsin, 2017Severe Thunderstorm Watches in South Dakota, 2017Every severe thunderstorm watch in 2017

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.