Severe Thunderstorm Watch 310

Issued

Jun 10, 2017, 10:01 PM CDT (03:01 UTC)

Expired

Jun 11, 2017, 5:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

65 kt

The Rapid City radar (KUDX), 70 km from the middle of the area, began a volume at 03:01 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

5%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 981Jun 10, 9:44 PM CDT
• Mesoscale Discussion 982Jun 10, 11:56 PM CDT
• Mesoscale Discussion 983Jun 11, 2:02 AM CDT

060 
WWUS20 KWNS 110257
SEL0  
SPC WW 110257
SDZ000-WYZ000-111000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 310
NWS Storm Prediction Center Norman OK
900 PM MDT Sat Jun 10 2017

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Western and central South Dakota
  Northeastern Wyoming

* Effective this Saturday night and Sunday morning from 900 PM
  until 400 AM MDT.

* Primary threats include...
  Scattered damaging winds and isolated significant gusts to 75
    mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Thunderstorms should continue to develop and gradually
increase in both coverage and intensity over the Black Hills region,
strengthening to severe levels over the next few hours.  A mix of
damaging wind and large hail is expected in the early stages. 
Activity then should shift into central South Dakota, assuming more
of an organized wind threat with time late tonight.

The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 65 miles west of Rapid
City SD to 80 miles east northeast of Pierre SD. 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.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26035.

...Edwards

Severe 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.