Alert archive / Illinois / Heat Advisories in 2021
Heat Advisory 3, NWS Chicago, IL
NWS Chicago, IL issued this heat advisory at Aug 24, 2021, 3:19 AM CDT for 12 counties in Illinois; 5 counties in Indiana. It took effect at Aug 24, 2021, 1:00 PM CDT. It was in force for 7 hr.
The area
The counties it named.
The facts
- Issued
- Aug 24, 2021, 3:19 AM CDT (08:19 UTC)
- In effect from
- Aug 24, 2021, 1:00 PM CDT
- Expired
- Aug 24, 2021, 8:00 PM CDT
- In force
- 7 hr
- Issued by
- NWS Chicago, IL
Counties Cook County, IL, DeKalb County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kankakee County, IL, Kendall County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Ogle County, IL, Will County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, Newton County, IN, Porter County, IN
The radar
The Chicago radar (KLOT), 33 km from the middle of the area, began a volume at 08:23 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 nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 8.3 hours before the alert went out and 135 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
- 329 J/kg
- Mixed-layer CIN
- -196 J/kg
- Mixed-layer LCL
- 1818 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 66 m²/s²
- 0-3 km storm-relative helicity
- 139 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Chicago, IL wrote its last area forecast discussion before this heat advisory went out at Aug 24, 3:17 AM CDT, 2 minutes earlier.
Area forecast discussion, Aug 24, 3:17 AM CDT, 2 minutes before
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</html>The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 24, 3:30 PM CDT | Special Marine Warning | LOT | 60 min | |
| Aug 24, 4:21 PM CDT | Special Weather Statement | LOT | Boone | 24 min |
| Aug 24, 4:33 PM CDT | Heat Advisory | LOT | Ford, Grundy, Iroquois, Kankakee, LaSalle, Livingston and 1 more | 26 hr |
| Aug 24, 4:58 PM CDT | Areal Flood Advisory | LOT | Boone, Lake, McHenry | 3 hr |
| Aug 24, 5:13 PM CDT | Special Weather Statement | LOT | DuPage | 32 min |
| Aug 24, 5:26 PM CDT | Severe Thunderstorm Warning | LOT | Boone, Lee, Ogle, Winnebago | 64 min |
| Aug 24, 5:28 PM CDT | Special Marine Warning | LOT | 92 min | |
| Aug 24, 5:40 PM CDT | Flash Flood Warning | LOT | Boone, McHenry | 4 hr |
| Aug 24, 6:09 PM CDT | Severe Thunderstorm Warning | LOT | Boone, DeKalb, Kane, Lee, McHenry, Ogle | 66 min |
| Aug 24, 6:13 PM CDT | Beach Hazards Statement | LOT | Cook, Lake | 4 hr |
| Aug 24, 6:19 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Lake | 17 min |
| Aug 24, 6:36 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Lake | 3 hr |
| Aug 24, 6:54 PM CDT | Special Weather Statement | LOT | Kendall, LaSalle | 51 min |
Nearby
Heat Advisories in Illinois, 2021Heat Advisories in Indiana, 2021Every heat advisory in 2021
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.