Hail in Chicago on Tuesday, September 7, 2021
The Storm Prediction Center logged 7 hail reports in Chicago on Tuesday, September 7, 2021, between 12:59 pm and 1:30 pm CDT, in 2 of the metro's 7 counties. The largest was 1.50 inches at Woodstock (McHenry County) at 1:27 pm. NOAA radar flagged 885 hail signatures inside the metro that day: 369 rated a 100% chance of hail and 333 with a maximum expected size of 1 inch or more.
Where hail was reported
Reports came from 6 places in Lake and McHenry counties, named as the National Weather Service described them.
- Round Lake 2 reports, up to 1.00 in
- Harvard 1 report, up to 1.50 in
- Johnsburg 1 report, up to 1.00 in
- Richmond 1 report, up to 1.00 in
- Spring Grove 1 report, up to 1.00 in
- Woodstock 1 report, up to 1.50 in
Every hail report logged that day
Times are Central Daylight Time. Sizes are in inches, as reported. The comment is the National Weather Service's text as published in the Storm Prediction Center's daily log.
| Time | Size | Place | County | NWS comment |
|---|---|---|---|---|
| 12:59 pm | 1.50 | Harvard | McHenry | TIME ESTIMATED BY RADAR. (LOT) |
| 1:16 pm | 1.00 | 2 E Richmond | McHenry | (LOT) |
| 1:20 pm | 1.00 | Spring Grove | McHenry | (LOT) |
| 1:23 pm | 1.00 | 1 NW Johnsburg | McHenry | QUARTER SIZE HAIL REPORT FROM MPING. TIME ESTIMATED FROM RADAR. (LOT) |
| 1:27 pm | 1.50 | Woodstock | McHenry | (LOT) |
| 1:29 pm | 1.00 | Round Lake | Lake | TIME ESTIMATED BY RADAR. LOCATION APPROXIMATED BY WFO BGM... CALLER ONLY GAVE ZIP CODE. (LOT) |
| 1:30 pm | 1.00 | Round Lake | Lake | TIME ESTIMATED FROM RADAR. (LOT) |
What NEXRAD radar recorded inside the metro
885 signatures from 10 radars fell inside the metro's counties on this local date, counting every cell the algorithm rated from a 10% to a 100% chance of hail; 369 were rated 100% and 63 had a maximum expected size of 2 inches or more.
| Radar | Signatures | Rated 100% | 1 in or more | 2 in or more | Largest expected | First | Last |
|---|---|---|---|---|---|---|---|
| KMDW | 229 | 94 | 77 | 7 | 2.00 in | 1:16 pm | 6:24 pm |
| KMKE | 217 | 84 | 95 | 16 | 2.75 in | 12:49 pm | 4:10 pm |
| KMKX | 115 | 55 | 43 | 13 | 4.00 in | 12:41 pm | 6:23 pm |
| KLOT | 113 | 43 | 42 | 15 | 4.00 in | 12:48 pm | 6:21 pm |
| KDVN | 91 | 36 | 32 | 8 | 2.75 in | 12:47 pm | 6:26 pm |
| KIWX | 53 | 25 | 20 | 3 | 2.25 in | 1:29 pm | 6:19 pm |
| KILX | 53 | 21 | 16 | 0 | 1.50 in | 2:20 pm | 6:24 pm |
| KGRR | 8 | 8 | 8 | 1 | 2.00 in | 1:20 pm | 1:45 pm |
| KIND | 4 | 2 | 0 | 0 | 0.75 in | 3:37 pm | 5:51 pm |
| KGRB | 2 | 1 | 0 | 0 | 0.50 in | 1:33 pm | 1:42 pm |
Each radar that scans a storm writes its own signature about every 4 to 6 minutes, so one storm produces many rows and overlapping radars count it more than once. The raw rows for this day are in NOAA's Severe Weather Data Inventory.
Check an address for September 7, 2021
See, free, how many hail signatures NOAA recorded within 1, 3 and 5 miles of one address that day and the nearest spotter report. The full report is $19.
Spotter reports come from the Storm Prediction Center's preliminary daily logs, grouped here by local calendar date (Central Daylight Time) and by county: a report counts for Chicago when its coordinates fall inside one of the metro's 7 counties (Cook, DuPage, Kane, Lake, McHenry, Will and Kendall counties). Radar signatures are estimates from the Hail Detection Algorithm, not measured stones; they include every cell it rated, from a 10% to a 100% probability of hail. How these pages are built.