Alert archive / Colorado / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 147, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 19, 2021, 6:21 PM MDT for Phillips County, Colorado. It was in force for 24 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 19, 2021, 6:21 PM MDT (00:21 UTC)
- Expired
- Aug 19, 2021, 6:45 PM MDT
- In force
- 24 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 1.5 in
- Wind
- 60.0 mph
County Phillips County, CO
The radar
The Goodland radar (KGLD), 132 km from the middle of the area, began a volume at 00:22 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 |
|---|---|---|---|
| Aug 19, 1:14 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 19, 5:25 PM MDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 0.4 hours before the alert went out and 115 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
- 56 J/kg
- Mixed-layer CIN
- -210 J/kg
- Mixed-layer LCL
- 1497 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
622
WUUS55 KBOU 200021
SVRBOU
COC095-200045-
/O.NEW.KBOU.SV.W.0147.210820T0021Z-210820T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
621 PM MDT Thu Aug 19 2021
The National Weather Service in Denver Colorado has issued a
* Severe Thunderstorm Warning for...
Southeastern Phillips County in northeastern Colorado...
* Until 645 PM MDT.
* At 621 PM MDT, a severe thunderstorm was located near Pleasant
Valley, or 10 miles southeast of Holyoke, moving northeast at 25
mph.
HAZARD...Ping pong 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 be near...
Pleasant Valley around 630 PM MDT.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1100 PM MDT for northeastern
Colorado.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.
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.
A Tornado Watch remains in effect until 1100 PM MDT for northeastern
Colorado.
&&
LAT...LON 4044 10220 4047 10226 4071 10205 4044 10205
TIME...MOT...LOC 0021Z 220DEG 21KT 4050 10213
TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
RPKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 6:41 PM MDT | Severe Thunderstorm Warning | BOU | Phillips | 49 min |
| Aug 19, 6:43 PM MDT | Areal Flood Advisory | BOU | Phillips | 2 hr |
| Aug 19, 7:43 PM MDT | Flash Flood Warning | BOU | Phillips | 3 hr |
| Aug 19, 10:38 PM MDT | Flash Flood Warning | BOU | Phillips | 4 hr |
| Aug 20, 2:12 AM MDT | Areal Flood Advisory | BOU | Larimer | 93 min |
| Aug 20, 2:15 AM MDT | Flash Flood Warning | BOU | Larimer | 2 hr |
| Aug 20, 2:58 AM MDT | Areal Flood Warning | BOU | Phillips | 9 hr |
| Aug 20, 4:01 AM MDT | Special Weather Statement | BOU | Morgan | 44 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.