RSS FeedsSevere Weather of August 23, 2007
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Severe weather reports from Illinois for Thursday, August 23, 2007 (click image to enlarge) |
National reports of severe weather for Thursday, August 23, 2007 (click image for specific details) |
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Strong to severe thunderstorms moved out of southeast Iowa during the midday hours of August 23. They intensified and raced northeast across northern Illinois, causing significant damage across portions of Warren and Knox Counties, as well as the Chicago metropolitan area. This particular page will focus on the Knox County portion of the storms.
Surveys conducted by the Lincoln NWS office, as well as the Knox County EMA, confirmed that widespread damage across the city of Galesburg was caused by wind gusts in the 70 to 80 mph range. These wind estimates continued for several miles past Galesburg, to the Wataga and Victoria areas. Within the city of Galesburg, enhanced damage was caused by a fast-moving microburst, which produced estimated wind speeds of around 100 mph.
Radar loop of storm moving across Knox County (1.3 MB)
The area of widespread wind damage was caused by an intensifying area of thunderstorms, which moved into west central Knox County shortly after 1 pm. These storms were moving from southwest to northeast, at 55-60 mph.
The area of damage was about 8 miles wide. A wind gust of 74 mph was reported at the Galesburg Municipal Airport at 1:09 pm, before the automated weather station failed. Damage began in the city of Galesburg around 1:10 pm, and continued within the city limits for approximately 5 minutes. There were more than 500 trees either damaged or destroyed. Falling trees or large tree limbs resulted in significant damage to dozens of buildings and vehicles. Numerous buildings sustained damage to roofing and chimneys, as well as minor damage to siding and broken windows. About 20 power poles were snapped, and numerous power lines were brought down. At least two semi-trailers were blown over on U.S. Highway 34 west of Galesburg, and on I-74 just east of Galesburg.
An area of enhanced wind damage was found within the city as well. This area was about 1/2 mile wide, and 2 miles long. It began close to the intersection of Knox and Pine Streets, and continued to the northeast, crossing the intersections of Grand Avenue and Oak Street, Farnham and East Main Street, and extending to Illini Drive and the Soangetaha Country Club east of I-74. Significant damage to trees, fences, garages and a business occurred around 1:15 pm. Several homes sustained roof and siding damage, primarily from debris and falling tree limbs.
The storm injured 7 people in Galesburg, with cuts and broken bones. Another 22 people sustained minor injuries during the cleanup effort. More than 10,000 customers in the city were without power.
Information for Knoxville, Wataga, and Victoria:
The city of Knoxville, about 4 miles southeast of Galesburg, also sustained widespread wind damage, shortly after 1:15 pm. Wind speeds were estimated to be 60-80 mph. Extensive damage was done to trees and power lines. Roofs and autos were damaged, mainly from falling trees and limbs.
Wataga, 4 miles northeast of Galesburg, was affected by the high winds around 1:20 pm. Winds estimated at 60-80 m ph also produced damage to trees, and downed power lines.
The town of Victoria, 15 miles east-northeast of Galesburg, also sustained 60-80 mph wind gusts. The damaging wind struck around 1:25 pm, downing trees and power lines. A man was killed in rural Victoria after a falling tree struck him.
Numerous farm fields sustained damage in northern Knox County, due to the high winds. Corn stalks and soybean plants were flattened as a result.
Radar and Weather Images (click images to enlarge):
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This is the noon weather map for northern and central Illinois and adjacent areas. The shading indicates the Convective Available Potential Energy (CAPE). The highest values are indicated by the yellow, orange and red shades, of approximately 2500 J/kg or above. Lifted index values are shown by the orange dashed lines. Across Galesburg and vicinity, temperatures were in the mid to upper 80s with dewpoints in the mid 70's. Significantly cooler conditions were noted further northwest, with temperatures around 70 degrees northwest of the Quad Cities. |
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The Lincoln radar image from 12:43 pm shows the thunderstorms well west of Galesburg, in Henderson County. |
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By 12:54 pm, the storms were beginning to move into Kirkwood, in western Warren County. Damage surveys conducted by the Quad Cities NWS indicate that winds of 100 mph were produced by these storms. |
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The radar image from 1:05 pm showed the storms were approaching the Warren/Knox county line. |
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The 1:10 pm radar image showed the leading edge of the storms coming into Galesburg. The Galesburg airport reported a 74 mph wind gust at 1:09 pm. |
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At 1:15 pm, damage was beginning to occur in Knoxville, southeast of Galesburg. |
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The radar image from 1:31 pm showed the thunderstorms beginning to take more of a "bow" shape, as indicated by the bulge in the echoes across southwest Stark and northwest Peoria counties. |
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This image from 1:42 pm showed the line of thunderstorms mainly out of Knox County. The storms travelled approximately 60 miles over the course of an hour (first image in this sequence to last image). |
Pictures (click images to enlarge):
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PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LINCOLN IL
1003 PM CDT THU AUG 23 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0105 PM TSTM WND DMG 1 W GALESBURG 40.95N 90.40W
08/23/2007 KNOX IL EMERGENCY MNGR
LARGE HIGH VOLTAGE TRANSMISSION LINES BLOWN DOWN...PART
OF A ROOF OF A COMERCIAL BUILDING BLOWN OFF...AND A SEMI
BLOWN OVER ON US ROUTE 34.
0109 PM TSTM WND GST GALESBURG 40.95N 90.38W
08/23/2007 M74.00 MPH KNOX IL AWOS
REPORTED AT THE GALESBURG AWOS...RELAYED FROM SPC
0110 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL EMERGENCY MNGR
POWER POLES DOWN AT RT 41 AND MONMOUTH AVE IN
GALESBURG...AND RIDING LAWNMOWERS BLOWN INTO THE STREET.
REPORT FROM KNOX COUNTY EM
0112 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL TRAINED SPOTTER
3 TO 4 INCH DIAMETER TREE LIMBS DOWN AT SANDBURG MALL IN
GALESBURG. TIME ESTIMATED...REPORT OCCURRED BETWEEN 107
AND 117PM. ESTIMATED 60-70MPH WINDS
0115 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL CO-OP OBSERVER
ESTIMATED 100MPH WIND GUST. TREES DOWN AND POWER OUTAGES
IN GALESBURG. REPORT FROM NEAR US ROUTE 34 AND SEMINARY
ROAD
0115 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL CO-OP OBSERVER
SEVERAL TRAILERS DAMAGED...STORE SIGN BLOWN OVER...TIME
ESTIMATED BETWEEN 110 PM AND 120 PM.
0115 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL TRAINED SPOTTER
LARGE OAK TREES UPROOTED...TREES DOWN ON GARAGES AND
HOUSES OFF OF FREEMONT STREET. EXTENSIVE DAMAGE ON THE
NORTHEAST SIDE OF GALESBURG
0115 PM TSTM WND DMG GALESBURG 40.95N 90.38W
08/23/2007 KNOX IL PUBLIC
NUMEROUS TREES UP TO 1 FOOT DIAMETER AND POWER LINES DOWN
ON HARRISON ST...ROCK ISLAND AVE...LANE ST AND MOISIER ST
ON THE NORTHEAST SIDE OF GALESBURG.
0117 PM TSTM WND DMG KNOXVILLE 40.91N 90.29W
08/23/2007 KNOX IL CO-OP OBSERVER
ESTIMATED WINDS OF 60 TO 80 MPH...TREES AND POWERLINES
DOWN. EXTENSIVE DAMAGE THROUGHOUT KNOXVILLE
0120 PM TSTM WND DMG VICTORIA 41.03N 90.10W
08/23/2007 KNOX IL EMERGENCY MNGR
*** 1 FATAL *** PART OF A TREE WAS BLOWN DOWN AND FELL ON
A MAN WALKING UP THE SHORE OF A SMALL LAKE NEAR THE TOWN
OF VICTORIA. REPORTED BY KNOX COUNTY ESDA. WIDESPREAD
WIND DAMAGE OCCURRED ACROSS ALL OF KNOX COUNTY...WITH THE
MOST EXTENSIVE DAMAGE IN GALESBURG...WATAGA...AND
VICTORIA. AT LEAST 8000 PEOPLE WERE WITHOUT POWER AT THIS
TIME IN THE COUNTY.
0145 PM TSTM WND DMG TOULON 41.09N 89.86W
08/23/2007 STARK IL LAW ENFORCEMENT
SEVERAL REPORTS OF TREES AND POWERLINES DOWN THROUGHOUT
STARK COUNTY. REPORT FROM STARK COUNTY SHERIFF
0150 PM TSTM WND DMG PRINCEVILLE 40.93N 89.76W
08/23/2007 PEORIA IL EMERGENCY MNGR
3 INCH DIAMETER LIVE TREE LIMBS DOWN ON THE WEST SIDE OF
PRINCEVILLE...FROM PEORIA COUNTY EMERGENCY MANAGER
0150 PM TSTM WND DMG TOULON 41.09N 89.86W
08/23/2007 STARK IL EMERGENCY MNGR
WINDOWS BLOWN OUT IN A CHURCH IN TOULON
0215 PM TSTM WND DMG HENRY 41.11N 89.36W
08/23/2007 MARSHALL IL MESONET
TREES BLOWN DOWN AND LIMBS DOWN. FROM SWOP OBSERVER.
0215 PM TSTM WND DMG LACON 41.02N 89.41W
08/23/2007 MARSHALL IL LAW ENFORCEMENT
TREES AND POWERLINES DOWN ACROSS MARSHALL COUNTY
0236 PM TSTM WND DMG 5 NE SPRING BAY 40.87N 89.46W
08/23/2007 WOODFORD IL EMERGENCY MNGR
TREE BLOWN ON ROUTE 26 AND LOON CREEK ROAD NORTH OF
SPRING BAY
0635 PM HAIL BRADFORD 41.18N 89.66W
08/23/2007 M0.75 INCH STARK IL CO-OP OBSERVER
0645 PM TSTM WND DMG BRADFORD 41.18N 89.66W
08/23/2007 STARK IL CO-OP OBSERVER
LARGE TREE BRANCHES DOWN.
0714 PM TSTM WND DMG HENRY 41.11N 89.36W
08/23/2007 MARSHALL IL EMERGENCY MNGR
LIMBS BLOWN DOWN ON POWER LINES. FROM COUNTY ESDA.
0715 PM TSTM WND DMG HENRY 41.11N 89.36W
08/23/2007 MARSHALL IL MESONET
POWER LINES DOWN. FROM HENRY CITY ESDA SWOP OBSERVER.
0730 PM TSTM WND GST 2 SW TOULON 41.07N 89.89W
08/23/2007 M61 MPH STARK IL CO-OP OBSERVER
TIME ESTIMATED. OBSERVER REPORTED SEVERAL TREES DOWN AND
NUMEROUS CORN STALKS BLOWN DOWN. REPORT FROM COOP
OBSERVER
0740 PM TSTM WND DMG CAMP GROVE 41.08N 89.63W
08/23/2007 MARSHALL IL EMERGENCY MNGR
LIMBS DOWN. FROM COUNTY ESDA.
0820 PM HAIL HENRY 41.11N 89.36W
08/23/2007 M1.00 INCH MARSHALL IL MESONET
0827 PM HEAVY RAIN HENRY 41.11N 89.36W
08/23/2007 M2.24 INCH MARSHALL IL MESONET
2.24 INCHES OF RAIN SINCE THIS AFTERNOON. FROM SWOP
OBSERVER.
