A very powerful, near-record low pressure system over Minnesota pushed a cold front across northern Illinois and northwest Indiana on the morning of Tuesday, October 26th, 2010 which aided in the development of strong to severe thunderstorms. Thunderstorms stretched all the way from northern Wisconsin across Illinois and into Missouri. Storms intensified in a line as they crossed northern Illinois just prior to daybreak. Several storms were able to develop rotating updrafts which can lead to wind damage and, in some cases, tornadoes. Numerous reports of damage were received from a variety of areas including Kane, Will, Kankakee, and Iroquois Counties in Illinois and in Porter County in Indiana.
The 955.2 millibar pressure at the deepest time of this low pressure recorded in Bigfork, Minnesota on October 26, 2010 appears to be the lowest extratropical sea level pressure on the record books in the mainland United States, excluding the west and east coasts.
For more on the pressure of this system and how it stacks up with U.S. records, please visit this page by the NWS Duluth: http://www.crh.noaa.gov/dlh/?n=101026_pressurerecords
The radar image below shows the expansive line of showers and thunderstorms associated with the deep low and attendant cold front at 7 AM CDT/8 AM EDT on October 26th. The white circular lines show the strong low pressure which is centered over north central Minnesota in this image.
Peotone Tornado (EF 2)
A tornado rated at EF 2 strength on the enhanced Fujita tornado scale was confirmed by National Weather Service Meteorologists surveying the damage.
A tornado touched down between Peotone and Beecher at 7:40 am the morning of October 26th... about 4 miles east of Peotone. The tornado's path length was surveyed to be 2.9 miles...with a path width of 200 yards. The tornado produced its most intense damage at 30651 South WIll Center Road removing a house's roof...collapsing exterior walls on the second floor of the house... and completely destroying a garage and 2-3 other outbuildings. Four power poles were also downed just northeast of the area along Peotone-Beecher Road. Additional EF1 and EF0 damage was found along a path running southwest toward Kennedy Road. This damage consisted of collapsed outbuildings, snapped cedar trees, and minor damage to homes.
EF2 tornado damage to home east of Peotone, IL
EF2 tornado damage to farm outbuildings east of Peotone, IL, looking northeast
Debris path from EF2 tornado east of Peotone, IL, looking northeast toward Peotone-Beecher Road
Funnel cloud near Peotone. Photo courtesy Carol Cantone.
Elburn Tornado (EF 1)
A tornado rated at EF1 on the enhanced Fujita tornado scale was confirmed by a National Weather Service storm survey team surveying the damage near Elburn, IL.
A tornado touched down about 2 miles northwest of Elburn in Kane County at 6:55 AM on October 26th. The tornado's path length was surveyed to be about 3/4 of a mile... with a path width of 50 yards. Two barns and a grain bin were destroyed along with a pole snapped at the base at one farmstead... and there was damage to a homestead two other farmsteads nearby. Debris from some of the damaged structures was blown 1/4 mile downstream.
Map of tornado path near Elburn, IL
EF1 tornado damage northwest of Elburn, IL. Photo by Andrew Pritchard.
Malden-Kouts Tornado (EF 0)
Another tornado rated at EF 0 strength was confirmed by an NWS survey team surveying the damage between Malden and Kouts in Porter County, IN.
This tornado touched down 4 miles southeast of Malden at 8:33 AM on October 26th. The tornado's path length was surveyed to be about 200 yards... with a path width of 30 yards. One outbuilding was damaged by this tornado.
Ashton Tornado (EF 1)
A fourth tornado rated at EF 1 was confirmed by a NWS survey team surveying the damage 3 miles southeast of Ashton in Lee County, IL.
A tornado touched down near Meridian Road southeast of Ashton at approximately 5:41 AM on October 26th. The tornado's path length was surveyed at 0.8 miles long with a debris path that was 50 yards wide, convergent and narrow. Some of the damage included a couple of outbuildings with poor structural integrity, and a few that had their roofs ripped off. The top of a metal silo was 'punched' in and a grain cart was flipped on to its side. In addition to the structural damage, numerous 2x4's were speared into the ground and metal siding was strewn into the fields to the northeast of the farm. The winds were estimated to be at 95 MPH.
Path of EF1 tornado in Lee County (roughly a mile long, with EF1 damage only at the start).
EF1 tornado damage southeast of Ashton, IL.
The Fujita Scale
The EF tornado scale is used to assign a tornado a rating based on estimated wind speeds and related damage. When tornado related damage is surveyed... it is compared to a list of damage indicators and degrees of damage which help estimate better the range of wind speeds the tornado likely produced. From this... a rating (zero to five) is assigned.
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
224 PM CDT THU OCT 28 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
0633 AM NON-TSTM WND GST 3 NNW DIXON 41.89N 89.51W
10/26/2010 M71.00 MPH LEE IL TRAINED SPOTTER
RECORDED BY COCORAHS OBSERVER.
0953 AM NON-TSTM WND DMG WOODSTOCK 42.31N 88.44W
10/26/2010 MCHENRY IL PUBLIC
TREE BRANCHES DOWN.
1028 AM NON-TSTM WND GST WAUKEGAN 42.37N 87.87W
10/26/2010 M62.00 MPH LAKE IL ASOS
1103 AM NON-TSTM WND GST PERU 41.34N 89.13W
10/26/2010 M58.00 MPH LA SALLE IL AWOS
1110 AM NON-TSTM WND GST 5 SSE BEACH PARK 42.36N 87.81W
10/26/2010 M56.00 MPH LMZ740 IL OFFICIAL NWS OBS
49 KNOT GUST MEASURED AT WAUKEGAN HARBOR GLOS WEATHER
1215 PM NON-TSTM WND GST 4 NE CHICAGO 41.92N 87.57W
10/26/2010 M75.00 MPH LMZ741 IL C-MAN STATION
65 KNOT GUST MEASURED AT CHICAGO CRIB.
0100 PM NON-TSTM WND GST 3 NE TOWN OF PINES 41.73N 86.91W
10/26/2010 M62.00 MPH LMZ046 IN C-MAN STATION
53 KNOT GUST MEASURED AT MICHIGAN CITY C-MAN STATION.
0510 PM NON-TSTM WND DMG 1 NE ELBURN 41.90N 88.46W
10/26/2010 KANE IL TRAINED SPOTTER
POWER LINE FELL ONTO A HOUSE...RESULTING IN A LARGE FIRE
ON A FARM ALONG IL-38.
1230 PM NON-TSTM WND DMG YORKVILLE 41.64N 88.45W
10/27/2010 KENDALL IL FIRE DEPT/RESCUE
WIND GUST GREATER THAN 50 MPH AT FIRE HOUSE. A 6 FT LONG
BRANCH /GREATER THAN 12 INCHES IN DIA/ FELL ON A
0200 PM NON-TSTM WND GST 3 NNW BURNS HARBOR 41.65N 87.15W
10/27/2010 M55.00 MPH LMZ745 IN OFFICIAL NWS OBS
48 KNOT GUST MEASURED AT BURNS HARBOR GLOS WEATHER
0206 PM NON-TSTM WND GST WAUKEGAN 42.37N 87.87W
10/27/2010 M61.00 MPH LAKE IL ASOS
0243 PM NON-TSTM WND GST PERU 41.34N 89.13W
10/27/2010 M58.00 MPH LA SALLE IL AWOS
0250 PM NON-TSTM WND GST 5 SSE BEACH PARK 42.36N 87.81W
10/27/2010 M56.00 MPH LMZ740 IL OFFICIAL NWS OBS
49 KNOT GUST MEASURED AT WAUKEGAN HARBOR GLOS WEATHER
0345 PM NON-TSTM WND GST GALE 41.60N 87.34W
10/27/2010 M61.00 MPH LAKE IN AWOS
0400 PM NON-TSTM WND GST 4 NE CHICAGO 41.92N 87.57W
10/27/2010 M76.00 MPH LMZ741 IL C-MAN STATION
66 KNOT GUST MEASURED AT CHICAGO CRIB.
0420 PM NON-TSTM WND DMG DE KALB 41.93N 88.75W
10/27/2010 DEKALB IL TRAINED SPOTTER
ROOF BLOWN OFF OF AN APARTMENT BUILDING ON GREENBRIER RD.
0515 PM NON-TSTM WND GST 3 NE TOWN OF PINES 41.73N 86.91W
10/27/2010 M64.00 MPH LMZ046 IN C-MAN STATION
56 KNOT GUST MEASURED AT MICHIGAN CITY C-MAN STATION.
0819 PM NON-TSTM WND GST ROCKFORD 42.27N 89.06W
10/27/2010 M58.00 MPH WINNEBAGO IL ASOS
PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE CHICAGO IL 1202 PM CDT THU OCT 28 2010/102 PM EDT THU OCT 28 2010/ ...ANOTHER DAY OF STRONG WINDS ON WEDNESDAY... IT WAS ANOTHER WINDY DAY AS STRONG WINDS ASSOCIATED WITH THE STORM SOME ARE DUBBING "CHI-CLONE 2010" CONTINUED TO BUFFET THE AREA. HERE IS A SUMMARY OF THE OFFICIAL PEAK WIND GUSTS RECORDED FROM ASOS SITES AROUND THE REGION WEDNESDAY... WAUKEGAN - 61 MPH (206 PM) ROCKFORD - 58 MPH (819 PM) AURORA - 55 MPH (320 PM) MIDWAY - 55 MPH (336 PM) O`HARE - 55 MPH (350 PM) WEST CHICAGO - 54 MPH (112 PM) VALPARAISO - 53 MPH (246 PM) WHEELING - 51 MPH (210 PM) THE FOLLOWING IS A LIST OF MAXIMUM WIND GUSTS REPORTED AT AREA AWOS SITES. NOTE: THESE SITES ARE NOT QUALITY CONTROLLED BY THE NATIONAL WEATHER SERVICE. ALSO...AWOS SITES DO NOT REPORT PEAK WINDS AND THE MAXIMUM WINDS HERE ARE BASED ON OBSERVATIONS TRANSMITTED EVERY 20 MINUTES. GARY - 61 MPH (345 PM) LASALLE/PERU - 58 MPH (243 PM) LOCKPORT - 54 MPH (245 PM) LANSING - 53 MPH (244 PM) PONTIAC - 52 MPH (225 PM) MORRIS - 51 MPH (225 PM) STERLING - 50 MPH (435 PM) KANKAKEE - 50 MPH (244 PM) DEKALB - 47 MPH (205 PM) JOLIET - 46 MPH (243 PM) ROCHELLE - 45 MPH (345 PM) THE FOLLOWING PEAK WIND GUSTS ARE FROM VARIOUS PRIVATE AND SCHOOL WEATHER STATIONS AND ARE ALSO NOT QUALITY CONTROLLED BY THE NATIONAL WEATHER SERVICE. NAPERVILLE - 56 MPH GLENVIEW - 54 MPH LINCOLNSHIRE - 53 MPH MATTESON - 53 MPH MINOOKA - 52 MPH SAUK VILLAGE - 52 MPH WGN TV - 52 MPH GENEVA - 51 MPH LIBERTYVILLE EOC - 51 MPH MARSEILLES - 51 MPH WHEATON - 51 MPH WAUKEGAN - 50 MPH ALGONQUIN - 50 MPH SCHAUMBURG - 49 MPH ORLAND PARK - 49 MPH MCHENRY - 49 MPH ADDISON - 48 MPH DEKALB - 47 MPH GURNEE - 46 MPH ITASCA - 46 MPH LINDENHURST - 45 MPH ELGIN - 45 MPH FOX LAKE - 45 MPH BUFFALO GROVE - 44 MPH LAGRANGE - 44 MPH PARK RIDGE - 43 MPH RENSSELAER - 43 MPH ONARGA - 41 MPH THE FOLLOWING ARE MAXIMUM WIND GUSTS RECORDED ON WEDNESDAY AT LAKE MICHIGAN MARINE WEATHER STATIONS AND BUOYS OWNED AND MAINTAINED BY NOAA. CHICAGO CRIB (~85` EL) - 76 MPH/66 KNOTS (400 PM) MICHIGAN CITY (~70` EL) - 64 MPH/56 KNOTS (515 PM) NORTH BUOY (~11` EL) - 59 MPH/51 KNOTS (950 AM) WAUKEGAN HARBOR (~30` EL) - 56 MPH/49 KNOTS (250 PM) BURNS HARBOR (~33` EL) - 55 MPH/48 KNOTS (200 PM) SOUTH BUOY (16` EL) - 52 MPH/45 KNOTS (850 PM) CALUMET HARBOR (~30` EL) - 51 MPH/44 KNOTS (154 PM)
For more on this event, please see this thorough review from the NWS Duluth office.