Alert archive / Illinois / Tornado Warnings in 2015
Tornado Warning 13, NWS Chicago, IL
NWS Chicago, IL issued this tornado warning at Apr 9, 2015, 7:51 PM CDT for LaSalle County, Illinois. It was in force for 39 min. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Apr 9, 2015, 7:51 PM CDT (00:51 UTC)
- Expired
- Apr 9, 2015, 8:30 PM CDT
- In force
- 39 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.75 in
County LaSalle County, IL
The radar
The Chicago radar (KLOT), 90 km from the middle of the area, began a volume at 00:52 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 9, 8:15 PM CDT | TSTM WND GST 70 | Lostant, IL | |
| Apr 9, 8:15 PM CDT | HAIL 1 | 2 S Lostant, IL | NEAR IL-18 AND I39. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
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 |
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 0.9 hours before the alert went out and 118 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.
822
WFUS53 KLOT 100051
TORLOT
ILC099-100130-
/O.NEW.KLOT.TO.W.0013.150410T0051Z-150410T0130Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
751 PM CDT THU APR 9 2015
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHWESTERN LA SALLE COUNTY IN NORTH CENTRAL ILLINOIS...
* UNTIL 830 PM CDT
* AT 751 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED OVER VARNA...OR 9 MILES EAST OF LACON...MOVING
NORTHEAST AT 45 MPH.
HAZARD...TORNADO AND GOLF BALL SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED.
DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR. TREE
DAMAGE IS LIKELY.
* THIS DANGEROUS STORM WILL BE NEAR...
TONICA AROUND 810 PM CDT.
STREATOR AROUND 820 PM CDT.
GRAND RIDGE AROUND 825 PM CDT.
OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
KANGLEY...LOSTANT AND LEONORE.
THIS INCLUDES... MATTHIESSEN STATE PARK AND STARVED ROCK STATE PARK.
INCLUDING THE FOLLOWING INTERSTATE...
I-39 BETWEEN MILE MARKERS 41 AND 52.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.
&&
LAT...LON 4137 8897 4117 8873 4110 8890 4111 8893
4109 8893 4105 8905 4110 8905 4110 8916
4121 8916
TIME...MOT...LOC 0051Z 233DEG 39KT 4105 8922
TORNADO...RADAR INDICATED
HAIL...1.75IN
$$
IZZI3 follow-up statements
813
WWUS53 KLOT 100103
SVSLOT
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
803 PM CDT THU APR 9 2015
ILC099-100130-
/O.CON.KLOT.TO.W.0013.000000T0000Z-150410T0130Z/
LA SALLE IL-
803 PM CDT THU APR 9 2015
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
SOUTHWESTERN LA SALLE COUNTY...
AT 803 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR WENONA...OR 11 MILES SOUTH OF OGLESBY...MOVING
NORTHEAST AT 60 MPH.
HAZARD...TORNADO AND GOLF BALL SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE
TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR. TREE DAMAGE IS
LIKELY.
THIS DANGEROUS STORM WILL BE NEAR...
STREATOR AROUND 815 PM CDT.
GRAND RIDGE AROUND 820 PM CDT.
OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
KANGLEY...LOSTANT AND LEONORE.
THIS INCLUDES... MATTHIESSEN STATE PARK AND STARVED ROCK STATE PARK.
INCLUDING THE FOLLOWING INTERSTATE...
I-39 BETWEEN MILE MARKERS 41 AND 52.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.
&&
LAT...LON 4137 8897 4117 8873 4110 8890 4111 8893
4109 8893 4105 8905 4110 8905 4110 8916
4121 8916
TIME...MOT...LOC 0103Z 233DEG 50KT 4113 8905
TORNADO...RADAR INDICATED
HAIL...1.75IN
$$
IZZI612
WWUS53 KLOT 100117
SVSLOT
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
817 PM CDT THU APR 9 2015
ILC099-100130-
/O.CON.KLOT.TO.W.0013.000000T0000Z-150410T0130Z/
LA SALLE IL-
817 PM CDT THU APR 9 2015
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
SOUTHWESTERN LA SALLE COUNTY...
AT 816 PM CDT...A CLUSTER OF SEVERE THUNDERSTORMS CAPABLE OF
PRODUCING TORNADOES WAS LOCATED FROM NEAR GRAND RIDGE TO NEAR
WENONA...MOVING NORTHEAST AT 60 MPH.
HAZARD...TORNADO AND GOLF BALL SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE
TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR. TREE DAMAGE IS
LIKELY.
THESE DANGEROUS STORMS WILL BE NEAR...
STREATOR AND GRAND RIDGE AROUND 830 PM CDT.
OTHER LOCATIONS IMPACTED BY THESE TORNADIC STORMS INCLUDE KANGLEY...
LOSTANT AND LEONORE.
THIS INCLUDES... MATTHIESSEN STATE PARK AND STARVED ROCK STATE PARK.
INCLUDING THE FOLLOWING INTERSTATE...
I-39 BETWEEN MILE MARKERS 41 AND 52.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE OUTDOORS...IN A
MOBILE HOME...OR IN A VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4137 8897 4117 8873 4110 8890 4111 8893
4109 8893 4105 8905 4110 8905 4110 8916
4121 8916
TIME...MOT...LOC 0116Z 232DEG 51KT 4124 8887 4109 8906
TORNADO...RADAR INDICATED
HAIL...1.75IN
$$
IZZI184
WWUS53 KLOT 100132
SVSLOT
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
832 PM CDT THU APR 9 2015
ILC099-100141-
/O.EXP.KLOT.TO.W.0013.000000T0000Z-150410T0130Z/
LA SALLE IL-
832 PM CDT THU APR 9 2015
...THE TORNADO WARNING FOR SOUTHWESTERN LA SALLE COUNTY HAS
EXPIRED...
THE STORMS WHICH PROMPTED THE TORNADO WARNING APPEARS TO HAVE A
DIMINISHED TORNADO THREAT FOR NOW...HOWEVER ADDITIONAL TORNADOES ARE
POSSIBLE IF IT REINTENSIFIES. A SEVERE THUNDERSTORM WARNING STILL
REMAINS IN EFFECT FOR THE SOUTHEAST HALF OF LASALLE COUNTY UNTIL 845
PM AND A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTH
CENTRAL ILLINOIS.
LAT...LON 4137 8897 4117 8873 4110 8890 4111 8893
4109 8893 4105 8905 4110 8905 4110 8916
4121 8916
TIME...MOT...LOC 0130Z 233DEG 39KT 4124 8887 4109 8906
$$
IZZIThe 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, 7:53 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, 9:25 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Will | 35 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
Tornado Warnings in Illinois, 2015Every tornado warning in 2015Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.