Alert archive / Colorado / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 120, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 14, 2021, 5:11 PM MDT for Weld County, Colorado. It was in force for 32 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, 5:11 PM MDT (23:11 UTC)
- Expired
- Aug 14, 2021, 5:43 PM MDT
- In force
- 32 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
County Weld County, CO
The radar
The Cheyenne radar (KCYS), 39 km from the middle of the area, began a volume at 23:15 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 12:00Z, 11.2 hours before the alert went out and 157 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
- 157 J/kg
- Mixed-layer CIN
- -337 J/kg
- Mixed-layer LCL
- 1928 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- -20 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
483
WUUS55 KBOU 142311
SVRBOU
COC123-150000-
/O.NEW.KBOU.SV.W.0120.210814T2311Z-210815T0000Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
511 PM MDT Sat Aug 14 2021
The National Weather Service in Denver Colorado has issued a
* Severe Thunderstorm Warning for...
North central Weld County in northeastern Colorado...
* Until 600 PM MDT.
* At 510 PM MDT, a severe thunderstorm was located 11 miles east of
Rockport, or 19 miles southeast of Cheyenne, moving southeast at 10
mph.
HAZARD...Quarter size hail.
SOURCE...Radar indicated.
IMPACT...Damage to vehicles is expected.
* This severe thunderstorm will remain over mainly rural areas of
north central Weld County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4076 10459 4091 10468 4095 10461 4096 10454
4090 10443 4082 10436
TIME...MOT...LOC 2310Z 317DEG 8KT 4091 10458
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH
$$
RJK1 follow-up statement
878
WWUS55 KBOU 142343
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
543 PM MDT Sat Aug 14 2021
COC123-142353-
/O.CAN.KBOU.SV.W.0120.000000T0000Z-210815T0000Z/
Weld CO-
543 PM MDT Sat Aug 14 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL WELD COUNTY IS
CANCELLED...
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.
LAT...LON 4076 10459 4091 10468 4095 10461 4096 10454
4090 10443 4082 10436
TIME...MOT...LOC 2342Z 317DEG 8KT 4086 10451
$$
RJKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 6:10 PM MDT | Areal Flood Advisory | BOU | Grand | 99 min |
| Aug 14, 2:55 PM MDT | Areal Flood Advisory | BOU | Larimer | 96 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.