The wet summer of 2010 continues into September. A strong area of low pressure in North Dakota, along with a warm front lifting northward over southern Minnesota spawned severe thunderstorms that began in western Minnesota shortly after midnight on September 2, and moved across the state during the overnight hours. Many people woke up to the rumble of thunder in the wee hours of the morning.
A wide swath of central and southern Minnesota received from one half to an inch and a half of rain. There were also large hail and damaging winds reported. Hail the size of golf balls was reported west of Foley in Stearns County, and wind bent a rain road crossing arm at Olivia in Renville County. The heaviest rains were reported in Lincoln, Lyon and Redwood County. The heaviest rainfall reported so far was 5.2 inches in Arco and 4.8 inches at Ivanhoe in Lincoln County. Water covered a mile of Highway 16, 6 miles south of Hendricks in Lincoln County. The National Weather Service issued a flood warning for the Redwood River near Marshall in Lyon County. The predicted crest is 14.4 feet, four tenths of a foot above flood stage.
One interesting phenomena with this complex of thunderstorms were the strong winds associated with the dying thunderstorms as they moved to the east over the Duluth area. Wind gusts over 40 mph were reported in the Duluth-Superior area, with 52mph reported at the Duluth National Weather Service, and 58mph reported on the Blatnik bridge, south of downtown Duluth. These winds were associated with a wake low, which is a localized minimum in air pressure that can sometimes develop behind an area of thunderstorms that is weakening.
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1126 AM CDT THU SEP 02 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1017 PM HAIL 17 S PUKWANA 43.53N 99.17W
09/01/2010 E1.00 INCH BRULE SD TRAINED SPOTTER
0330 AM FLASH FLOOD MARSHALL 44.45N 95.79W
09/02/2010 LYON MN LAW ENFORCEMENT
WATER OVER HIGHWAY 59 IN MARSHALL
0335 AM TSTM WND DMG 6 S HENDRICKS 44.42N 96.43W
09/02/2010 LINCOLN MN PUBLIC
TREE BRANCHES 3 TO 4 INCHES IN DIAMETER BROKEN OFF. LOTS
OF TREE DEBRIS IN YARD.
0335 AM HAIL 6 S HENDRICKS 44.42N 96.43W
09/02/2010 E1.00 INCH LINCOLN MN PUBLIC
ALONG WITH 5 PLUS INCHES OF RAINFALL.
0335 AM FLASH FLOOD 6 S HENDRICKS 44.42N 96.43W
09/02/2010 LINCOLN MN PUBLIC
VERY HEAVY RAINFALL OF MORE THAN 5 INCHES. WATER COVERING
AREA ROADWAYS. HIGHWAY 16 HAS WATER OVER IT FOR A MILE IN
EITHER DIRECTION.
0345 AM FLASH FLOOD 5 W HENDRICKS 44.50N 96.53W
09/02/2010 BROOKINGS SD CO-OP OBSERVER
VERY HEAVY RAINFALL. MORE THAN 5 INCHES. DITCHES OVER
FLOWING AND FLOWING HEAVILY INTO NEARBY OAK LAKE.
SECONDARY ROADS ON THE WEST SIDE OF OAK LAKE ARE
PARTIALLY WASHED OUT.
0400 AM FLASH FLOOD WHITE 44.43N 96.65W
09/02/2010 BROOKINGS SD EMERGENCY MNGR
EM REPORTS FLOODING IN THE COUNTY.FLOODING REPORTED FROM
BUSHNELL TO WHITE AND NORTH TO THE COUNTY LINE.. TOWNSHIP
ROADS ALONG 6 MILE CREEK FROM WHITE NORTHWARD TO COUNTY
LINE ARE UNDERWATER.
0400 AM HAIL 9 N SLAYTON 44.12N 95.79W
09/02/2010 E0.88 INCH MURRAY MN PUBLIC
JUST A FEW STONES IN ADDITION TO MORE THAN 1.5 INCHES OF
RAIN.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
330 AM CDT THU SEP 02 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0100 AM NON-TSTM WND DMG OLIVIA 44.78N 95.00W
09/02/2010 RENVILLE MN LAW ENFORCEMENT
NUMEROUS ROAD SIGNS BLOW DOWN.
0105 AM TSTM WND DMG OLIVIA 44.78N 95.00W
09/02/2010 RENVILLE MN TRAINED SPOTTER
RAIL ROAD CROSSING ARM AT HWY 71 AND HWY 212...BENT IN
HIGH WINDS.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
221 AM CDT THU SEP 02 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0145 AM HAIL 4 W FOLEY 45.66N 93.99W
09/02/2010 M1.75 INCH BENTON MN LAW ENFORCEMENT
UP TO GOLF BALL SIZE HAIL REPORTED BY A DEPUTY WEST OF
FOLEY.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
159 AM CDT THU SEP 02 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0145 AM TSTM WND GST SARTELL 45.62N 94.21W
09/02/2010 M62 MPH STEARNS MN TRAINED SPOTTER
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
931 AM CDT THU SEP 02 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0610 AM NON-TSTM WND GST 6 NW DULUTH 46.84N 92.21W
09/02/2010 M52.00 MPH ST. LOUIS MN ASOS
MEASURED AT DULUTH INTERNATIONAL AIRPORT ASOS /DLH/. PEAK
WIND OF 45 KNOTS.
0614 AM NON-TSTM WND GST 2 NE SUPERIOR 46.72N 92.03W
09/02/2010 M44.00 MPH LSZ145 WI AWOS
GUSTS TO 38 KNOTS MEASURED AT SKY HARBOR AIRPORT /DYT/.
0615 AM NON-TSTM WND GST 2 SSE DULUTH 46.75N 92.10W
09/02/2010 M58.00 MPH LSZ145 MN MESONET
50 KNOT GUST MEASURED AT MINNESOTA DOT SITE ON BLATNIK
BRIDGE / PIER 20.
0618 AM NON-TSTM WND GST 1 SSE DULUTH 46.77N 92.11W
09/02/2010 M44.00 MPH ST. LOUIS MN OTHER FEDERAL
38.1 KNOT GUST MEASURED AT DULM5 GREAT LAKES MARINE /
WATER LEVEL OBSERVATION SITE.
0620 AM NON-TSTM WND GST 3 SE DULUTH 46.75N 92.07W
09/02/2010 M44.00 MPH LSZ145 MN PUBLIC
MEASURED ON A PRIVATE WEATHER STATION ON PARK POINT.
0802 AM NON-TSTM WND GST DEVILS ISLAND 47.07N 90.73W
09/02/2010 M43.00 MPH ASHLAND WI C-MAN STATION
37 KNOT PEAK WIND AT DEVILS ISLAND CMAN /DISW3/.
&&
WIND GUSTS OVER 40 MPH FROM THIS MORNING/S WAKE LOW EVENT. MANY OTHER
30-40MPH GUSTS WERE RECORDED...PARTICULARLY IN THE TWIN PORTS AREA.
WAKE LOWS ARE LOCALIZED MINIMA IN PRESSURE THAT SOMETIMES DEVELOP
BEHIND WEAKENING AREAS OF THUNDERSTORMS...AS WAS THE CASE THIS
MORNING. THE SHARPER CONTRAST IN PRESSURE OVER A SMALL AREA PRODUCES