Significant derecho in Chicago area

[Coredesat]

Chicago got a very bad derecho this evening, their radar is currently out of commission. Tons of storm reports:

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1016 PM CDT THU AUG 23 2007

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0955 PM FLASH FLOOD DE KALB 41.93N 88.75W
08/23/2007 DE KALB IL TRAINED SPOTTER

EXTENSIVE FLOODING TO BUILDINGS AT NIU CAMPUS

0250 PM TSTM WND DMG MERRILLVILLE 41.47N 87.33W
08/23/2007 LAKE IN OTHER FEDERAL

NUMEROUS LARGE TREES DOWN...SOME ON HOMES AND CARS. 30 TO
40 INCH DIAMETER TREES DOWNED...SOME UPROOTED AND SOME
SNAPPED. SIGNIFICANT DAMAGE DONE TO HOMES.

0305 PM TSTM WND DMG WEST CHICAGO 41.89N 88.22W
08/23/2007 DUPAGE IL LAW ENFORCEMENT

*** 40 INJ *** BUILDING COLLAPSE ON FENTON AVENUE. 40
INJURED...7 WENT TO HOSPITALS

0324 PM TSTM WND GST MANHATTAN 41.43N 87.99W
08/23/2007 E80.00 MPH WILL IL TRAINED SPOTTER

183RD AND WOLF ROAD

Tons more storm reports here: http://www.crh.noaa.gov/product.php?sit ... suedby=lot

[CajunMama]

Nate posted this link in chat of a picture of the storm rolling in

http://www.flickr.com/photos/matthewfield/1217009373

[Pebbles]

It was some nastiness that I've posted about in Tornado-Warnings in Chicagoland thread. But it didn't stop there. It's been thundering nonstop (and raining) for 10 hours now. And none too few that lightening strikes were quite close. I love weather but this constant booming noise (not to mention shaking the house) is starting to fray the nerves. The rain ditch in front of everyones houses are over full now and the front lawn looks like a pond.

[ohiostorm]

I was working at the Pittsburgh airport and was watching the storms roll through on our computers. Shortly after, we were flooded with passengers from American and United who canceled flights into O'hare. We re-booked them on Southwest to fly into Midway. Apparently their weather wasn't quite as bad there.

[wbug1]

major derecho in Chigago - this video shows winds near 100 mph, a tree in the bottom right goes down in the first 3 seconds and you can see tiles and some large chunks of roofing coming off all over the place. Considering that the material comes off quickly some of it going horizontally immediately after at as can clearly be seen at near 60 mph, I can't see the winds in this video being any less than 95 mph/150 kph.


http://www.youtube.com/watch?v=VC1GRKYqA08&mode=related&search=

[Pebbles]

Update: It's been 3 days since the storms. My aunt in Alsip (SW suburb of Chicago) was told she won't have power for another 3-5 days. Many people are without power for extended lengths of time. Unlike in hurricane zones.. most aren't prepared or use to going without power for extended periods. Let's just say allot of generators have been bought up here this weekend.

[CajunMama]

Pebbles, i'm guessing it was powerline damage from all the trees that's causing the extended poweroutages? That's happened here in the years between hurricanes the trees aren't pruned and people just plant more and more.

[SamSagnella]

Post-analysis revealed a large swath of damaging straight-line winds in excess of 60MPH, with embedded pockets of hurricane-force winds, that extended from West Chicago all the way to the shores of Lake Michigan. The only evidence of tornado damage was along a 1.5-mile long path through Winfield in western DuPage County.

NOUS43 KLOT 250048
PNSLOT

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
747 PM CDT FRI AUG 24 2007

...STORM SURVEYS CONDUCTED ACROSS PORTIONS OF DEKALB...DUPAGE AND
COOK COUNTIES...

...STRAIGHT LINE WIND DAMAGE FOUND ACROSS DUPAGE AND COOK COUNTIES...

SEVERE THUNDERSTORMS CAUSED EXTENSIVE WIND DAMAGE ACROSS PORTIONS OF
NORTHERN ILLINOIS THURSDAY AFTERNOON. NATIONAL WEATHER SERVICE STORM
SURVEY TEAMS EXAMINED WIND DAMAGE IN SEVERAL LOCATIONS ACROSS
DEKALB...DUPAGE AND COOK COUNTIES ON FRIDAY.

ACROSS DUPAGE AND PORTIONS OF NORTHERN AND CENTRAL COOK COUNTIES...A
NEARLY CONTINUOUS SWATH OF WIND DAMAGE WAS NOTED. THE MOST
SIGNIFICANT DAMAGE OCCURRED ALONG A PATH WHICH BEGAN IN FAR WESTERN
DUPAGE COUNTY NEAR THE INTERSECTION OF ROOSEVELT ROAD AND
WASHINGTON STREET IN WEST CHICAGO...AND CONTINUED EAST THROUGH THE
NORTHERN PORTIONS OF LOMBARD AND GLEN ELLYN...INTO NORTHLAKE...THEN
ACROSS THE NORTH SIDE OF CHICAGO TO THE LAKE MICHIGAN SHORE NEAR
MONTROSE HARBOR. ALONG THIS PATH...WIND DAMAGE WAS CONSISTENT WITH
WINDS IN THE 60 TO 80 MPH RANGE. HOWEVER...THERE WERE POCKETS OF
WIND DAMAGE SUGGESTIVE OF WINDS IN THE 80 TO 100 MPH RANGE INCLUDING
THE 4200 BLOCK OF NORTH ASHLAND AND ACROSS NORTHERN GLEN ELLYN SOUTH
OF GENEVA ROAD. THE WIND DAMAGE WAS APPROXIMATELY ONE HALF MILE WIDE
ALONG THIS PATH. A SEPARATE AREA OF WIND DAMAGE SUGGESTIVE OF WINDS
OF 80 TO 100 MPH WAS FOUND IN THE 4000 BLOCK OF NORTH SHERIDAN IN
THE WRIGLEYVILLE AREA WITH EXTENSIVE TREE DAMAGE AND SEVERAL
UPROOTED TREES IN THIS AREA. MUCH OF THE DAMAGE APPEARS TO BE
CONSISTENT WITH STRAIGHT LINE WINDS...WITH NO SIGNS OF SUSTAINED OR
ORGANIZED CIRCULATION OVER THE MAJORITY OF THE DAMAGE PATH.

...EF1 TORNADO DAMAGE FOUND IN WESTERN DUPAGE COUNTY...
WHILE OTHER DAMAGE APPEARS TO HAVE BEEN CAUSED BY STRAIGHT LINE
WINDS...DAMAGE INDICATING A TORNADIC CIRCULATION WAS FOUND IN
WINFIELD IN WESTERN DUPAGE COUNTY. THE TORNADO BEGAN NEAR PRINCE
CROSSING ROAD SOUTH OF GENEVA ROAD. THE TORNADO HAD A PATH LENGTH OF
APPROXIMATELY 1.5 MILES AND ENDED JUST WEST OF GARY AVENUE SOUTH OF
GENEVA ROAD. THE MAIN DAMAGE FROM THE TORNADO INCLUDED SEVERAL LARGE
UPROOTED HARDWOOD TREES. BASED ON THE OBSERVED DAMAGE...THE TORNADO
IS ESTIMATED TO HAVE BEEN APPROXIMATELY 300 TO 500 YARDS WIDE AND
RATED EF1 ON THE ENHANCED FUJITA SCALE WITH ESTIMATED WIND SPEEDS OF
86 TO 110 MPH. PRELIMINARY REVIEW OF RADAR DATA AND SPOTTER REPORTS
INDICATE THAT THE TORNADO OCCURRED AT APPROXIMATELY 308 PM CDT.

...ADDITIONAL SURVEYS...
IN DEKALB COUNTY....MINOR STRAIGHT LINE WIND DAMAGE TO LIMBS AND A
SHED DOOR WERE FOUND ACROSS THE MILAN...AFTON...PIERCE AND KANEVILLE
TOWNSHIPS SOUTH AND SOUTHEAST OF THE CITY OF DEKALB.

IN MOUNT PROSPECT IN NORTHERN COOK COUNTY...ROOF AND EXTERIOR WALL
DAMAGE WAS NOTED TO A ONE STORY GARAGE BUILDING IN AN APARTMENT
COMPLEX SOUTHWEST OF THE INTERSECTION OF GOLF ROAD AND BUSSE ROAD.
DAMAGE APPEARED TO BE ASSOCIATED WITH STRAIGHT LINE WINDS OF 80 TO
100 MPH. THROUGHOUT THE VILLAGE...NUMEROUS LARGE BROKEN TREE
LIMBS...SOME UPROOTED TREES AND A FEW SNAPPED TREE TRUNKS ALSO
APPEARED TO BE CONSISTENT WITH PEAK STRAIGHT LINE WIND SPEEDS OF 80
TO 100 MPH.

$$

IZZI/MERZLOCK/MARSILI/RATZER

[SamSagnella]

A few of the National Weather Service Forecast Offices have created web-based news articles about the effects of the August 23rd storms on their respsective county warning areas.

WFO DVN: Straight Line Wind Damage Confirmed in Warren County IL
WFO GRR: Thursday, August 23rd: Tornado in Northeast Montcalm County
WFO LOT: August 23rd 2007 Severe Weather Damage Survey/Radar Images (Updated 8/26)