Hills, Minnesota

The NWS Storm Prediction Center has issued a
Severe Thunderstorm Watch for portions of

       western Iowa
       southwest Minnesota
       northeast Nebraska
       southeast South Dakota

Effective this Thursday night and Friday morning from 705 PM
until 200 am CDT.

Hail to 3 inches in diameter... thunderstorm wind gusts to 70
mph... and dangerous lightning are possible in these areas.

The Severe Thunderstorm Watch area is approximately along and 95
statute miles east and west of a line from 25 miles west
northwest of Worthington Minnesota to 15 miles south southwest of
Tekamah Nebraska. For a complete depiction of the watch see the
associated watch outline update (wous64 kwns wou8).

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.

Discussion... cu/tcu field and scattered thunderstorms are beginning
to increase over northeast neb/southeast SD... and will likely track
eastward into IA through the evening. Other storms may redevelop
through the evening over this same area as low level jet increases.
Strong instability and 50-60 knots of effective shear will promote
supercells capable of very large hail and damaging winds.

Aviation... a few severe thunderstorms with hail surface and aloft
to 3 inches. Extreme turbulence and surface wind gusts to 60
knots. A few cumulonimbi with maximum tops to 500. Mean storm
motion vector 27030.


... Hart

... Flash Flood Watch now in effect from 10 PM CDT this evening
through Friday morning...

The Flash Flood Watch is now in effect for

* portions of southwest Minnesota and southeast South Dakota...
including the following areas... in southwest Minnesota...
Jackson... Nobles and rock. In southeast South Dakota... Bon
Homme... Hutchinson... McCook... Minnehaha and Turner.

* From 10 PM CDT this evening through Friday morning

* locally heavy rainfall of 1 to 2 inches is possible later
tonight. Rainfall rates of 1 to 3 inches per hour are also
possible... dropping an inch of rain or more in 15 to 30 minutes.

* Areas that have received heavy rains in the past 3 to 10 days
could see flash flooding on creeks and streams with these
additional rains... and any urbanized areas that receive the
heaviest rainfall rates could see widespread flooding of
streets and underpasses.

Precautionary/preparedness actions...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should flash flood warnings be issued.

... Severe Thunderstorm Watch safety rules...

A Severe Thunderstorm Watch means that conditions are favorable
for the development of severe weather in the designated area.
During a watch there is no cause for immediate concern. You should
go about your normal business... but be on the lookout and keep up
to date on the latest weather developments. Public safety
officials should activate prearranged plans.

A Severe Thunderstorm Warning... on the other hand... means that a
severe thunderstorm has been sighted or indicated by radar. People
in the path of the storm should take immediate action to safeguard
themselves and their family.

Technically speaking... a severe thunderstorm is defined as having
wind gusts which exceed 58 mph and/or hail at least 3/4 inch in
diameter. However... as these storms develop... they can be
accompanied by tornadoes. Listen to NOAA Weather Radio or other
local media to learn if a warning has been issued for your area.
Also... keep a close watch on the thunderstorms as tornadoes can
form quickly. If you see a tornado... move quickly into a basement.
If none is available... seek shelter in a small interior room on
the lowest floor and stay away from outside walls... doors and
windows. In schools... factories or other institutional type
buildings... stay out of auditoriums and gymnasiums.