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 647
NWS Storm Prediction Center Norman OK
800 PM CDT Wed Sep 11 2019
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
parts of central and eastern South Dakota
* Effective this Wednesday night and Thursday morning from 800 PM
until 300 AM CDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Isolated damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorms are forecast to continue increasing in
coverage this evening, across the South Dakota vicinity, with
isolated severe storms gradually evolving within the larger area of
convection. Large hail is expected to be the primary severe risk,
though locally damaging winds -- and possibly a tornado -- will also
be a possibility this evening.
The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 55 miles southwest of
Pierre SD to 15 miles north northeast of Sioux Falls SD. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU7).
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 645...WW 646...
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 600. Mean storm motion vector