861
WWUS20 KWNS 211113
SEL5
SPC WW 211113
IAZ000-211800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 275
NWS Storm Prediction Center Norman OK
615 AM CDT Tue May 21 2024

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
  Central and southern Iowa

* Effective this Tuesday morning and afternoon from 615 AM until
  100 PM CDT.

* 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
  A tornado or two possible

SUMMARY...Clusters of thunderstorms -- including an organized bowing
complex initially over eastern NE -- will pose a threat mainly for
severe gusts while crossing the watch area from west to east.  A
tornado or two cannot be ruled out, especially near an outflow
boundary draped across central/south-central IA.  Isolated large
hail is possible.  This is a precursor to the main severe-weather
threat expected later today, for which we have a "Moderate Risk"
outlook.

The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 80 miles west of Des
Moines IA to 25 miles south southeast of Cedar Rapids IA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU5).

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 274...

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 550. Mean storm motion vector
26045.

...Edwards