URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 631
NWS Storm Prediction Center Norman OK
925 PM CDT Fri Aug 11 2023
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Extreme southern Iowa
Extreme west central Illinois
* Effective this Friday night and Saturday morning from 925 PM
until 400 AM CDT.
* Primary threats include…
Scattered large hail and isolated very large hail events to 2.5
inches in diameter likely
Scattered damaging wind gusts to 70 mph possible
SUMMARY…Scattered supercells are expected to form and persist for
the next few hours, with the potential to produce isolated very
large hail up to 2.5 inches in diameter. There will also be some
potential for upscale growth into a cluster later tonight, with an
attendant increase in the threat for damaging winds.
The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 40 miles southwest of
Lamoni IA to 15 miles east northeast of Quincy IL. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).
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 627…WW 628…WW
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