Alert archive / Colorado / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 121, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 14, 2021, 7:38 PM MDT for Weld County, Colorado. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 14, 2021, 7:38 PM MDT (01:38 UTC)
- Expired
- Aug 14, 2021, 8:30 PM MDT
- In force
- 52 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Hail
- 1.75 in
- Wind
- 60.0 mph
County Weld County, CO
The radar
The Cheyenne radar (KCYS), 42 km from the middle of the area, began a volume at 01:40 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
Denver, CO (KDNR), launched 00:00Z, 1.6 hours before the alert went out and 154 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
- 666 J/kg
- Mixed-layer CIN
- -45 J/kg
- Mixed-layer LCL
- 3335 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -22 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted.
023
WUUS55 KBOU 150138
SVRBOU
COC123-150230-
/O.NEW.KBOU.SV.W.0121.210815T0138Z-210815T0230Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
738 PM MDT Sat Aug 14 2021
The National Weather Service in Denver Colorado has issued a
* Severe Thunderstorm Warning for...
Northwestern Weld County in northeastern Colorado...
* Until 830 PM MDT.
* At 737 PM MDT, a severe thunderstorm was located 7 miles southeast
of South Greeley, or 9 miles southeast of Cheyenne, moving south at
25 mph.
HAZARD...Golf ball size hail and 60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees. People and
animals outdoors will be injured. Expect hail damage to
roofs, siding, windows, and vehicles.
* This severe thunderstorm will remain over mainly rural areas of
northwestern Weld County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4073 10476 4100 10480 4099 10422 4075 10410
TIME...MOT...LOC 0137Z 355DEG 21KT 4104 10469
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
RJKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 6:48 PM MDT | Flash Flood Warning | BOU | Larimer | 115 min |
| Aug 14, 7:15 PM MDT | Special Weather Statement | BOU | Summit | 30 min |
| Aug 14, 8:01 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 44 min |
| Aug 14, 8:28 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 47 min |
| Aug 14, 8:29 PM MDT | Severe Thunderstorm Warning | BOU | Sedgwick | 46 min |
| Aug 14, 8:43 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Washington | 47 min |
| Aug 14, 9:15 PM MDT | Severe Thunderstorm Warning | BOU | Phillips, Sedgwick | 14 min |
| Aug 14, 9:28 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Washington | 47 min |
| Aug 14, 9:31 PM MDT | Special Weather Statement | BOU | Weld | 44 min |
| Aug 15, 2:32 PM MDT | Areal Flood Advisory | BOU | Grand | 88 min |
| Aug 15, 5:19 PM MDT | Special Weather Statement | BOU | Lincoln | 41 min |
| Aug 15, 5:25 PM MDT | Special Weather Statement | BOU | Teller | 65 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 2021Every severe thunderstorm warning 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.