Alert archive / Illinois / Severe Thunderstorm Warnings in 2015
Severe Thunderstorm Warning 21, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Apr 9, 2015, 9:25 PM CDT for Cook County, DuPage County, Will County, Illinois; Lake County, Indiana. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2015, 9:25 PM CDT (02:25 UTC)
- Expired
- Apr 9, 2015, 10:00 PM CDT
- In force
- 35 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Cook County, IL, DuPage County, IL, Will County, IL, Lake County, IN
The radar
The Chicago radar (KLOT), 43 km from the middle of the area, began a volume at 02:28 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 9, 1:48 PM CDT | Tornado Watch | SPC | 9 hr |
| Apr 9, 8:55 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 2.4 hours before the alert went out and 197 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1160 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 1435 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 296 m²/s²
- 0-3 km storm-relative helicity
- 356 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 15.8
The text
As transmitted, in the capitals the NWS used until 2016.
749
WUUS53 KLOT 100225
SVRLOT
ILC031-043-197-INC089-100300-
/O.NEW.KLOT.SV.W.0021.150410T0225Z-150410T0300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
925 PM CDT THU APR 9 2015
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN COOK COUNTY IN NORTHEASTERN ILLINOIS...
NORTH CENTRAL WILL COUNTY IN NORTHEASTERN ILLINOIS...
SOUTHEASTERN DUPAGE COUNTY IN NORTHEASTERN ILLINOIS...
NORTHWESTERN LAKE COUNTY IN NORTHWESTERN INDIANA...
* UNTIL 1000 PM CDT
* AT 924 PM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM JUSTICE TO FLOSSMOOR...MOVING NORTHEAST AT 50 MPH.
HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED.
IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE
TO ROOFS...SIDING AND TREES.
* SEVERE THUNDERSTORMS WILL BE NEAR...
LANSING...MIDWAY AIRPORT...SOUTH HOLLAND...EVERGREEN PARK AND
PHOENIX AROUND 930 PM CDT.
CICERO...BERWYN...CALUMET CITY...DOLTON...CHATHAM...STICKNEY...
BURNHAM...BRIDGEPORT AND ENGLEWOOD AROUND 935 PM CDT.
HAMMOND...GARY...EAST CHICAGO...WHITING...MEIGS FIELD...DOUGLAS
PARK AND HYDE PARK AROUND 940 PM CDT.
NAVY PIER AROUND 945 PM CDT.
OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
DOWNTOWN CHICAGO.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.
&&
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTHEASTERN
ILLINOIS.
LAT...LON 4164 8743 4146 8786 4169 8810 4191 8763
4190 8761 4190 8760 4187 8761 4184 8761
4178 8756 4177 8756 4175 8753 4171 8753
4167 8747 4167 8742
TIME...MOT...LOC 0224Z 235DEG 44KT 4174 8785 4155 8767
HAIL...1.00IN
WIND...60MPH
$$
RC2 follow-up statements
044
WWUS53 KLOT 100247
SVSLOT
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
947 PM CDT THU APR 9 2015
ILC043-100256-
/O.CAN.KLOT.SV.W.0021.000000T0000Z-150410T0300Z/
DUPAGE IL-
947 PM CDT THU APR 9 2015
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DUPAGE COUNTY IS
CANCELLED...
THE STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE WARNED
AREA.THEREFORE THE WARNING HAS BEEN CANCELLED.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTHEASTERN
ILLINOIS.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 200 AM CDT FOR
NORTHWESTERN INDIANA.
LAT...LON 4164 8743 4146 8786 4166 8800 4191 8763
4190 8761 4190 8760 4187 8761 4184 8761
4178 8756 4177 8756 4175 8753 4171 8753
4167 8747 4167 8742
TIME...MOT...LOC 0246Z 235DEG 44KT 4189 8756 4170 8738
$$
ILC031-197-INC089-100300-
/O.CON.KLOT.SV.W.0021.000000T0000Z-150410T0300Z/
COOK IL-WILL IL-LAKE IN-
947 PM CDT THU APR 9 2015
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR SOUTHEASTERN COOK...NORTH CENTRAL WILL AND NORTHWESTERN LAKE
COUNTIES...
AT 946 PM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEAR NAVY PIER TO NEAR EAST CHICAGO...MOVING NORTHEAST
AT 50 MPH.
HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED.
IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE TO
ROOFS...SIDING AND TREES.
THESE SEVERE THUNDERSTORMS WILL REMAIN OVER MAINLY RURAL AREAS OF
SOUTHEASTERN COOK...NORTH CENTRAL WILL AND NORTHWESTERN LAKE
COUNTIES...INCLUDING THE FOLLOWING LOCATIONS...CALUMET PARK...SOUTH
CHICAGO...EAST HAZEL CREST...RIVERDALE...PALOS HEIGHTS...ROBBINS...
ORLAND HILLS...HOMETOWN...FRANKFORT SQUARE AND PALOS PARK.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.
&&
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTHEASTERN
ILLINOIS.
LAT...LON 4164 8743 4146 8786 4166 8800 4191 8763
4190 8761 4190 8760 4187 8761 4184 8761
4178 8756 4177 8756 4175 8753 4171 8753
4167 8747 4167 8742
TIME...MOT...LOC 0246Z 235DEG 44KT 4189 8756 4170 8738
HAIL...1.00IN
WIND...60MPH
$$
MTF/RC824
WWUS53 KLOT 100256
SVSLOT
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
956 PM CDT THU APR 9 2015
ILC031-197-INC089-100306-
/O.EXP.KLOT.SV.W.0021.000000T0000Z-150410T0300Z/
COOK IL-WILL IL-LAKE IN-
956 PM CDT THU APR 9 2015
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN COOK...NORTH
CENTRAL WILL AND NORTHWESTERN LAKE COUNTIES WILL EXPIRE AT 1000 PM
CDT...
THE STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.
STORMS WITH GUSTY WINDS AND SMALL HAIL WILL CONTINUE THROUGH 1100 PM
CDT.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTHEASTERN
ILLINOIS.
TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
CHICAGO .
LAT...LON 4164 8743 4146 8786 4166 8800 4191 8763
4190 8761 4190 8760 4187 8761 4184 8761
4178 8756 4177 8756 4175 8753 4171 8753
4167 8747 4167 8742
TIME...MOT...LOC 0255Z 235DEG 44KT 4189 8756 4170 8738
$$
MTFThe office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 7:05 PM CDT | Tornado Warning | LOT | Boone, Ogle, Winnebago | 40 min |
| Apr 9, 7:16 PM CDT | Tornado Warning | LOT | Boone, DeKalb, McHenry | 29 min |
| Apr 9, 7:19 PM CDT | Severe Thunderstorm Warning | LOT | Lee, Ogle | 26 min |
| Apr 9, 7:19 PM CDT | Tornado Warning | LOT | McHenry | 26 min |
| Apr 9, 7:21 PM CDT | Areal Flood Advisory | LOT | Boone, McHenry, Ogle, Winnebago | 3 hr |
| Apr 9, 7:36 PM CDT | Severe Thunderstorm Warning | LOT | Ogle, Winnebago | 24 min |
| Apr 9, 7:41 PM CDT | Tornado Warning | LOT | McHenry | 49 min |
| Apr 9, 7:51 PM CDT | Tornado Warning | LOT | LaSalle | 39 min |
| Apr 9, 7:53 PM CDT | Severe Thunderstorm Warning | LOT | Boone, DeKalb, Kane, McHenry, Ogle, Winnebago | 37 min |
| Apr 9, 8:05 PM CDT | Severe Thunderstorm Warning | LOT | McHenry | 55 min |
| Apr 9, 8:21 PM CDT | Severe Thunderstorm Warning | LOT | LaSalle | 24 min |
| Apr 9, 8:21 PM CDT | Severe Thunderstorm Warning | LOT | Lake | 24 min |
| Apr 9, 8:26 PM CDT | Special Marine Warning | LOT | 94 min | |
| Apr 9, 8:40 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Kendall, LaSalle, Will | 35 min |
| Apr 9, 8:58 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kendall, Will | 32 min |
| Apr 9, 9:08 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Will | 37 min |
| Apr 9, 9:34 PM CDT | Special Marine Warning | LOT | 116 min | |
| Apr 9, 9:40 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois | 35 min |
| Apr 9, 10:27 PM CDT | Wind Advisory | LOT | Boone, DeKalb, DuPage, Ford, Grundy, Iroquois and 10 more | 6 hr |
| Apr 10, 9:06 AM CDT | River Flood Advisory | LOT | Boone | 36 hr |
| Apr 10, 10:52 AM CDT | River Flood Warning | LOT | Lake | 4 days |
| Apr 10, 11:19 AM CDT | River Flood Advisory | LOT | Cook | 3 days |
| Apr 10, 11:19 AM CDT | River Flood Advisory | LOT | Cook | 36 hr |
| Apr 10, 11:39 AM CDT | River Flood Advisory | LOT | Lake | 36 hr |
| Apr 10, 11:50 AM CDT | River Flood Advisory | LOT | Kane, Kendall | 5 days |
| Apr 10, 12:17 PM CDT | River Flood Watch | LOT | Kane, McHenry | 5 days |
| Apr 10, 2:17 PM CDT | Wind Advisory | LOT | Boone, DeKalb, DuPage, Ford, Grundy, Iroquois and 10 more | 5 hr |
Nearby
Severe Thunderstorm Warnings in Illinois, 2015Severe Thunderstorm Warnings in Indiana, 2015Every severe thunderstorm warning in 2015
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.