Hail in Denver on Thursday, August 19, 2021
The Storm Prediction Center logged 22 hail reports in Denver on Thursday, August 19, 2021, between 2:25 pm and 4:05 pm MDT, in 4 of the metro's 7 counties. The largest was 2.00 inches at 4 ESE White Ranch Open (Jefferson County) at 2:25 pm. NOAA radar flagged 825 hail signatures inside the metro that day: 217 rated a 100% chance of hail and 224 with a maximum expected size of 1 inch or more.
Where hail was reported
Reports came from 9 places in Adams, Broomfield, Douglas and Jefferson counties, named as the National Weather Service described them.
- Westminster 8 reports, up to 1.50 in
- Arvada 3 reports, up to 1.50 in
- Bennett 2 reports, up to 1.50 in
- Broomfield 2 reports, up to 1.25 in
- Castle Rock 2 reports, up to 1.00 in
- Federal Heights 2 reports, up to 1.25 in
- Northglenn 1 report, up to 1.00 in
- The Pinery 1 report, up to 1.00 in
- White Ranch Open 1 report, up to 2.00 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 |
|---|---|---|---|---|
| 2:25 pm | 2.00 | 4 ESE White Ranch Open | Jefferson | REPORT FROM MPING: HEN EGG (2.00 IN.). (BOU) |
| 2:28 pm | 1.00 | 2 WNW Arvada | Jefferson | (BOU) |
| 2:29 pm | 1.50 | 4 W Arvada | Jefferson | (BOU) |
| 2:30 pm | 1.00 | 2 SSW Castle Rock | Douglas | (BOU) |
| 2:33 pm | 1.00 | 3 S Castle Rock | Douglas | REPORT FROM MPING: QUARTER (1.00 IN.). (BOU) |
| 2:40 pm | 1.00 | 2 NE Arvada | Jefferson | (BOU) |
| 2:45 pm | 1.50 | 2 WSW Westminster | Jefferson | REPORT FROM MPING: PING PONG BALL (1.50 IN.). (BOU) |
| 2:45 pm | 1.00 | 1 NNW Federal Heights | Adams | (BOU) |
| 2:45 pm | 1.25 | 1 SSE Broomfield | Jefferson | (BOU) |
| 2:46 pm | 1.50 | 1 WSW Westminster | Jefferson | (BOU) |
| 2:47 pm | 1.00 | 2 W Westminster | Jefferson | 98TH AND SHEIRIDAN. (BOU) |
| 2:48 pm | 1.00 | Westminster | Adams | REPORT FROM MPING: QUARTER (1.00 IN.). (BOU) |
| 2:49 pm | 1.00 | 2 WSW Westminster | Jefferson | REPORT FROM MPING: QUARTER (1.00 IN.). (BOU) |
| 2:50 pm | 1.25 | 2 N Federal Heights | Adams | (BOU) |
| 2:50 pm | 1.00 | 1 ENE Westminster | Adams | (BOU) |
| 2:50 pm | 1.00 | 2 NE Westminster | Adams | (BOU) |
| 2:50 pm | 1.25 | 1 NNW Westminster | Jefferson | (BOU) |
| 2:53 pm | 1.00 | 2 E Broomfield | Broomfield | REPORT FROM MPING: QUARTER (1.00 IN.). (BOU) |
| 3:06 pm | 1.00 | 2 NE Northglenn | Adams | REPORT FROM MPING: QUARTER (1.00 IN.). (BOU) |
| 3:45 pm | 1.00 | The Pinery | Douglas | (BOU) |
| 4:02 pm | 1.50 | 1 W Bennett | Adams | REPORT FROM MPING: PING PONG BALL (1.50 IN.). (BOU) |
| 4:05 pm | 1.25 | Bennett | Adams | (BOU) |
What NEXRAD radar recorded inside the metro
825 signatures from 5 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; 217 were rated 100% and 30 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 |
|---|---|---|---|---|---|---|---|
| KPUX | 249 | 68 | 71 | 11 | 2.25 in | 12:45 pm | 5:38 pm |
| KDEN | 225 | 46 | 39 | 0 | 1.50 in | 11:09 am | 5:36 pm |
| KCYS | 170 | 53 | 51 | 11 | 3.00 in | 12:41 pm | 5:47 pm |
| KFTG | 145 | 30 | 43 | 6 | 3.25 in | 12:42 pm | 5:45 pm |
| KGLD | 36 | 20 | 20 | 2 | 2.50 in | 4:25 pm | 5:44 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 August 19, 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 Denver when its coordinates fall inside one of the metro's 7 counties (Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas and Jefferson 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.