Scattered severe weather occurred over parts of south-central and southeast Wisconsin during the overnight hours of July 30th. The severe weather consisted of powerful downburst, straight-line winds and large hail. Some large trees were uprooted and/or large tree branches knocked out of trees. Some power lines were probably snapped or were arcing. A couple roads were blocked until authorities removed tree debris. Maximum wind gusts were on the order of 58 to 65 mph and hail stone diameters were 1 inch.
Beneficial rains fell, but as usual amounts varied from a few hundredths to over an inch. Very little if any rain fell west of Dane County. However, 2 to 2.5 inches may have fallen near the intersection of CTH J and H in north central Sheboygan County, based on doppler radar estimates. Here at the NWS office southeast of Sullivan in east-central Jefferson County we picked up 0.38 inch. We'll take it!
The storms and beneficial rains were associated with a weak cold front that moved southeast across Wisconsin. Below is a 4-panel display showing what the storms looked like on radar at 1050 PM, 1219 AM, and 110 AM. In the upper left is a surface weather map showing the cold front and other surface features at 1200 AM. Click on image for larger version
Below is a graphic showing estimated rainfall amounts based on Dual Pol technology. Click on image for larger version.
Below are some severe weather reports. If you had tree damage or large hail last night (other than what is below), feel free to send your information to firstname.lastname@example.org.
NWUS53 KMKX 310940
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
440 AM CDT TUE JUL 31 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
1140 PM HAIL 1 NW SUN PRAIRIE 43.19N 89.25W
07/30/2012 M1.00 INCH DANE WI TRAINED SPOTTER
1140 PM HAIL WEST BEND 43.42N 88.18W
07/30/2012 M0.50 INCH WASHINGTON WI TRAINED SPOTTER
LASTED APPROXIMATELY THREE MINUTES.
1143 PM HAIL SUN PRAIRIE 43.18N 89.23W
07/30/2012 M0.88 INCH DANE WI TRAINED SPOTTER
VEHICLE DAMAGE REPORTED WITH NICKEL SIZE HAIL.
1201 AM HAIL JACKSON 43.32N 88.16W
07/31/2012 M0.50 INCH WASHINGTON WI TRAINED SPOTTER
HEAVY RAIN...VISIBILITY LESS THAN A 1/4 MILE.
1237 AM TSTM WND GST PALMYRA 42.88N 88.59W
07/31/2012 E50.00 MPH JEFFERSON WI TRAINED SPOTTER
1242 AM TSTM WND GST PALMYRA 42.88N 88.59W
07/31/2012 M57.00 MPH JEFFERSON WI TRAINED SPOTTER
1247 AM TSTM WND DMG 3 ENE LA GRANGE 42.82N 88.55W
07/31/2012 WALWORTH WI 911 CALL CENTER
A COUPLE TREES DOWN IN THE AREA FROM 3 ENE LA GRANGE TO 5
ENE OF LA GRANGE. ONE OF THE TREES BLOCKED A ROAD. TIME
IS ESTIMATED BASED ON RADAR.
1250 AM HAIL 2 E NORTH PRAIRIE 42.94N 88.36W
07/31/2012 M1.00 INCH WAUKESHA WI TRAINED SPOTTER
1257 AM TSTM WND DMG 6 SW MUSKEGO 42.83N 88.20W
07/31/2012 RACINE WI 911 CALL CENTER
TREE DOWN AT BIG BEND ROAD AND N LAKE DRIVE. TIME
1257 AM HAIL 5 S WAUKESHA 42.94N 88.24W
07/31/2012 M0.25 INCH WAUKESHA WI TRAINED SPOTTER
0105 AM TSTM WND DMG 5 NNW WATERFORD 42.83N 88.25W
07/31/2012 RACINE WI 911 CALL CENTER
A COUPLE LARGE TREES DOWN IN THE CALDWELL AREA AND IN THE
TICHIGAN AREA WEST AND NORTH OF TICHIGAN LAKE. TIME IS
ESTIMATED BASED ON RADAR.
0105 AM HAIL 4 WNW GREENDALE 42.96N 88.07W
07/31/2012 M0.50 INCH MILWAUKEE WI LAW ENFORCEMENT
ON HIGHWAY 43 NEAR 124TH ST. TIME ESTIMATED.
0140 AM MARINE TSTM WIND 1 E DOWNTOWN KENOSHA 42.58N 87.80W
07/31/2012 M45.00 MPH LMZ646 WI C-MAN STATION
KENOSHA MARINE OBSERVATION RECORDED A 39 KNOT MARINE
THUNDERSTORM WIND GUST.
The storms generated damaging winds and dumped large hail in northeast Wisconsin. For information, click here.