Alert archive / Colorado / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 409, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Sep 20, 2026, 10:06 PM MDT for Elbert County, Colorado. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Sep 20, 2026, 10:06 PM MDT (04:06 UTC)
- Expired
- Sep 20, 2026, 10:45 PM MDT
- In force
- 39 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
County Elbert County, CO
The radar
The Denver radar (KFTG), 66 km from the middle of the area, began a volume at 04:10 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 20, 9:01 PM MDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Grand Junction, CO (KGJT), launched 00:00Z, 4.1 hours before the alert went out and 376 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2280 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- -7 m²/s²
- 0-3 km storm-relative helicity
- 50 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Denver/Boulder, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 20, 5:32 PM MDT, 4 hours 34 minutes earlier.
Area forecast discussion, Sep 20, 5:32 PM MDT, 4 hours 34 minutes before
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</html>The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 7:15 PM MDT | Special Weather Statement | BOU | Sedgwick | 45 min |
| Sep 20, 9:29 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 31 min |
| Sep 20, 9:40 PM MDT | Areal Flood Advisory | BOU | Douglas, Elbert | 3 hr |
| Sep 20, 9:52 PM MDT | Severe Thunderstorm Warning | BOU | Douglas, Elbert | 26 min |
| Sep 20, 10:09 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 38 min |
| Sep 20, 10:29 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 46 min |
| Sep 20, 10:44 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 46 min |
| Sep 20, 11:39 PM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 51 min |
| Sep 21, 12:07 AM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 23 min |
| Sep 21, 12:28 AM MDT | Severe Thunderstorm Warning | BOU | Elbert, Lincoln | 19 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 2026Every severe thunderstorm warning in 2026
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.