Wednesday, July 25, 2012

Mesoscale Discussion 23:35:01.8405198

AREAS AFFECTED...EASTERN IA/SOUTHERN WI/FAR NORTHERN IL

CONCERNING...SEVERE THUNDERSTORM WATCH 520...523...

VALID 260434Z - 260600Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
520...523...CONTINUES.

SUMMARY...SEVERE TSTM WATCHES 520/523 CONTINUE UNTIL 07Z/08Z
RESPECTIVELY. DAMAGING WINDS WILL REMAIN A CONCERN INTO THE EARLY
PART OF THE OVERNIGHT FROM FAR EASTERN IA INTO SOUTHERN WI/EXTREME
NORTHERN IL. ADDITIONAL PARTS OF NORTHEAST IL WILL BE MONITORED OVER
THE NEXT FEW HOURS FOR THE POSSIBILITY OF SEVERE TSTM WATCH
EXPANSION.

DISCUSSION...A LONG-LIVED MCS CONTINUES TO NEAR THE MS RIVER
VICINITY OF NORTHEAST IA/SOUTHWEST WI AS OF 0415Z...WITH AID OF
EXTENSIVE TRAILING PRECIPITATION/COLD POOL...LIKELY MCV
INFLUENCES...AND STRENGTHENING LOW-LEVEL JET/MEAN WESTERLIES.
STRONG/SEVERE WINDS HAVE REMAINED COMMON...WITH 53 KT MEASURED GUST
AT CEDAR RAPIDS IA AND A 49 KT MEASURED GUST AT IOWA CITY OVER THE
PAST HOUR /SINCE 0345Z/. WHILE BOUNDARY LAYER CINH HAS INCREASED
OVER THE PAST FEW HOURS...EXISTING ORGANIZED NATURE OF THE
MCS/ASSOCIATED COLD POOL AND RESIDUAL LAPSE RATES/BUOYANCY IN
VICINITY OF WSW-ENE EFFECTIVE FRONTAL ZONE WILL CONTINUE TO YIELD A
DAMAGING WIND/SOME HAIL THREAT INTO PARTS OF SOUTHERN WI/FAR
NORTHERN IL OVERNIGHT. LOCALLY HEAVY/REPETITIVE RAINFALL WILL BE A
CONCERN AS WELL.

..GUYER.. 07/26/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LOT...MKX...DVN...ARX...

LAT...LON 42399107 43179037 43569013 43878814 43828741 43528713
42628788 41598873 41219015 41879152 42399107