The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Click for Watch Status Reports
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 422
NWS Storm Prediction Center Norman OK
450 PM CDT Wed Jul 19 2017
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southeast South Dakota
* Effective this Wednesday afternoon from 450 PM until Midnight
* Primary threats include...
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...A cluster of storms along the South Dakota and Nebraska
border vicinity will likely continue to spread generally eastward
along an effective boundary, aided by a very hot/moist air mass near
and south of this boundary. Sporadic large hail will be possible
aside from damaging winds.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 30 miles west northwest
of Ainsworth NE to 40 miles northeast of Sioux City IA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU2).
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
OTHER WATCH INFORMATION...CONTINUE...WW 420...WW 421...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 600. Mean storm motion vector