Watch Possible for Central Iowa

In Mesoscale Discussions, Severe Weather, Weather by Henry LukerLeave a Comment

A Mesoscale Dicussion is out for Central Iowa

Cross Posted from the Iowa Weather Network WeatherBlog at iaswc.org!

The Storm Prediction Center has posted Mesoscale Discussion 1625 for Central Iowa due to the Fact of The threat of Severe WX Rising. A watch may be needed later this afternoon, so make sure to stay tuned to IowaWX.com for the latest! At the bottom of the post, you can find the Watch Text product.

AREAS AFFECTED…PARTS OF ERN NEB…SRN MN…NRN IA…SW WI
CONCERNING…SEVERE POTENTIAL…WATCH POSSIBLE
VALID 151921Z – 152115Z

TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF AN INCREASING
SEVERE THREAT THAT MAY REQUIRE A WATCH WITHIN THE NEXT HOUR OR TWO.

A GRADUAL INTENSIFICATION OF CONVECTIVE DEVELOPMENT IS ONGOING NEAR
A RESIDUAL OUTFLOW BOUNDARY OVER SOUTHERN MINNESOTA…SOUTH OF
REDWOOD FALLS. THIS APPEARS TO BE AIDED BY FORCING ASSOCIATED WITH
A WEAK MID-LEVEL SHORT WAVE IMPULSE/CYCLONIC VORTICITY
CENTER…WHICH IS EXPECTED TO SHIFT EASTWARD THROUGH SOUTHERN
MINNESOTA BETWEEN NOW AND 23-00Z. LAPSE RATES ARE NO LONGER
PARTICULARLY STEEP…BUT HIGH BOUNDARY LAYER MOISTURE CONTENT WITH
LOWER/MID 70S SURFACE DEW POINTS IS CONTRIBUTING TO SIZABLE CAPE IN
EXCESS OF 2000 J/KG. THIS WILL BE SUPPORTIVE OF VIGOROUS UPDRAFTS
CAPABLE OR PRODUCING VERY HEAVY RAIN AND PERHAPS SOME SMALL HAIL IN
THE PRESENCE OF A MODESTLY SHEARED 20-30 KT WESTERLY DEEP LAYER MEAN
FLOW. AN ISOLATED TORNADO MAY NOT BE COMPLETELY OUT OF THE QUESTION
ALONG THE BOUNDARY…NEAR THE IOWA/MINNESOTA BORDER NORTHWARD
THROUGH MANKATO AND THE ROCHESTER AREA. HOWEVER…LOCALLY HEAVY
RAINFALL/FREQUENT CLOUD TO GROUND LIGHTNING AND DOWNBURSTS
ASSOCIATED WITH HEAVY PRECIPITATION LOADING APPEAR THE MORE
PROMINENT THREATS AS FAR EAST AS PERHAPS LA CROSSE THROUGH LATE
AFTERNOON.

ADDITIONAL STRONG/SEVERE STORM DEVELOPMENT IS EXPECTED TO GRADUALLY
DEVELOP SOUTHWARD ALONG THE WIND SHIFT ASSOCIATED WITH THE UPPER
IMPULSE…ACROSS PARTS OF CENTRAL AND WESTERN IOWA… INTO AREAS
NEAR/NORTH OF OMAHA NEBRASKA.

..KERR.. 07/15/2011

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