Forecast and Conditions for Sioux City, Iowa

Updated: 7:35 PM CDT on July 09, 2009 Observed at Le Mars, Iowa
Temperature	82 °F
Humidity	79%
Dew Point	75 °F
Wind	SSE at 6 mph
Pressure	29.90 in (Rising)
Conditions	Overcast
Visibility	10.0 miles
Clouds	Overcast (OVC) : 6500 ft
Yesterday's Maximum	80 °F
Yesterday's Minimum	65 °F
Normal high	86 °F
Normal low	63 °F
Record high	103 °F (1930)
Record low	41 °F (1895)
Yesterday's Heating Degree Days	0
Yesterday's Cooling Degree Days	8
Sunrise	05:57 AM (CDT)
Sunset	09:04 PM (CDT)
Moon Rise	10:25 PM (CDT)
Moon Set	08:03 AM (CDT)
Moon Phase

Severe Thunderstorm Watch Statement as of 7:05 PM CDT on July 9, 2009

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 Statement as of 6:14 PM CDT on July 9, 2009

... Flash Flood Watch remains in effect through Friday morning...

The Flash Flood Watch continues for

* portions of northwest Iowa... northeast Nebraska and southeast
South Dakota... including the following areas... in northwest
Iowa... Buena Vista... Cherokee... Clay... Dickinson... Ida...
Lyon... Obrien... Osceola... Plymouth... Sioux and Woodbury. In
northeast Nebraska... Dakota and Dixon. In southeast South
Dakota... Clay... Lincoln... Union and Yankton.

* Through Friday morning

* locally heavy rainfall of 1 to 3 inches is possible tonight.
Rainfall rates of 2 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.

Forecast as of 7:45 PM CDT on July 9, 2009
Severe Thunderstorm Watch 568 in effect until 2 am CDT Friday...

	Rest of Tonight Thunderstorms becoming likely. Lows in the upper 60s. East winds 5 to 15 mph. Chance of rain 70 percent.
	Friday Mostly cloudy. Chance of thunderstorms in the morning... then slight chance of thunderstorms in the afternoon. Highs in the lower 80s. Northeast winds 5 to 15 mph. Chance of rain 40 percent.
	Friday Night Mostly cloudy in the evening...then becoming partly cloudy. Lows in the lower 60s. Northeast winds 5 to 10 mph.
	Saturday Partly cloudy. Highs in the lower 80s. Northwest winds 5 to 10 mph becoming west in the afternoon.
	Saturday Night Partly cloudy in the evening...then mostly cloudy with a 20 percent chance of thunderstorms after midnight. Lows in the lower 60s. Southwest winds 5 to 10 mph becoming southeast after midnight.
	Sunday Partly sunny with a 30 percent chance of thunderstorms. Highs in the mid 80s.
	Sunday Night Mostly cloudy with a 40 percent chance of thunderstorms. Lows in the mid 60s.
	Monday Partly sunny with a 20 percent chance of thunderstorms. Highs in the mid 80s.
	Monday Night Mostly cloudy with a 30 percent chance of thunderstorms. Lows in the upper 60s.
	Tuesday Partly sunny with a 20 percent chance of thunderstorms. Highs in the mid 80s.
	Tuesday Night Partly cloudy with a 20 percent chance of thunderstorms. Lows in the lower 60s.
	Wednesday through Thursday Partly cloudy. Highs in the mid 80s. Lows in the lower 60s.