Hail in Fort Collins and Greeley on Thursday, May 20, 2021
The Storm Prediction Center logged 5 hail reports in Fort Collins and Greeley on Thursday, May 20, 2021, between 7:21 pm and 7:41 pm MDT, in 1 of the metro's 2 counties. The largest was 3.25 inches at 9 N Stoneham (Weld County) at 7:37 pm. NOAA radar flagged 258 hail signatures inside the metro that day: 106 rated a 100% chance of hail and 58 with a maximum expected size of 1 inch or more.
Where hail was reported
Reports came from 1 place in Weld County, named as the National Weather Service described them.
- Stoneham 5 reports, up to 3.25 in
Every hail report logged that day
Times are Mountain 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 |
|---|---|---|---|---|
| 7:21 pm | 1.25 | 1 WNW Stoneham | Weld | (BOU) |
| 7:27 pm | 2.00 | 3 NNW Stoneham | Weld | (BOU) |
| 7:29 pm | 3.00 | Stoneham | Weld | (BOU) |
| 7:37 pm | 3.25 | 9 N Stoneham | Weld | (BOU) |
| 7:41 pm | 2.75 | 3 NNW Stoneham | Weld | (BOU) |
What NEXRAD radar recorded inside the metro
258 signatures from 4 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; 106 were rated 100% and 10 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 |
|---|---|---|---|---|---|---|---|
| KCYS | 128 | 56 | 35 | 7 | 2.75 in | 2:59 pm | 7:44 pm |
| KFTG | 90 | 34 | 19 | 3 | 2.00 in | 3:56 pm | 7:42 pm |
| KDEN | 27 | 11 | 2 | 0 | 1.00 in | 4:02 pm | 5:23 pm |
| KPUX | 13 | 5 | 2 | 0 | 1.00 in | 4:27 pm | 5:14 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 May 20, 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 (Mountain Daylight Time) and by county: a report counts for Fort Collins and Greeley when its coordinates fall inside one of the metro's 2 counties (Larimer and Weld 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.