Alert archive / Colorado / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 17, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 12, 2021, 4:28 PM MDT for Logan County, Phillips County, Washington 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
- May 12, 2021, 4:28 PM MDT (22:28 UTC)
- Expired
- May 12, 2021, 5:00 PM MDT
- In force
- 32 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Logan County, CO, Phillips County, CO, Washington County, CO
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 10.5 hours before the alert went out and 71 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
- 1031 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 40 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
981
WUUS55 KBOU 122228
SVRBOU
COC075-095-121-122300-
/O.NEW.KBOU.SV.W.0017.210512T2228Z-210512T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boulder CO
Issued by National Weather Service Pueblo CO
428 PM MDT Wed May 12 2021
The National Weather Service in Boulder has issued a
* Severe Thunderstorm Warning for...
Northeastern Washington County in northeastern Colorado...
Southeastern Logan County in northeastern Colorado...
Southwestern Phillips County in northeastern Colorado...
* Until 500 PM MDT.
* At 428 PM MDT, a severe thunderstorm was located near St
Petersburg, or 20 miles southeast of Sterling, moving southeast at
30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Lone Star and St Petersburg.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4044 10278 4035 10278 4035 10280 4021 10280
4050 10309 4064 10295 4044 10245
TIME...MOT...LOC 2228Z 306DEG 27KT 4048 10287
HAIL...1.00IN
WIND...60MPH
$$
Rodriguez2 follow-up statements
536
WWUS55 KBOU 122241
SVSBOU
Severe Weather Statement
National Weather Service Boulder CO
Issued by National Weather Service Pueblo CO
441 PM MDT Wed May 12 2021
COC075-095-121-122300-
/O.CON.KBOU.SV.W.0017.000000T0000Z-210512T2300Z/
Washington CO-Logan CO-Phillips CO-
441 PM MDT Wed May 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR NORTHEASTERN WASHINGTON...SOUTHEASTERN LOGAN AND SOUTHWESTERN
PHILLIPS COUNTIES...
At 441 PM MDT, a severe thunderstorm was located near Lone Star, or
21 miles north of Yuma, moving southeast at 30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Lone Star and St Petersburg.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4044 10278 4035 10278 4035 10280 4021 10280
4045 10301 4058 10287 4044 10245
TIME...MOT...LOC 2241Z 304DEG 27KT 4042 10280
HAIL...1.00IN
WIND...60MPH
$$
Rodriguez292
WWUS55 KBOU 122256
SVSBOU
Severe Weather Statement
National Weather Service Boulder CO
Issued by National Weather Service Pueblo CO
456 PM MDT Wed May 12 2021
COC075-095-121-122305-
/O.EXP.KBOU.SV.W.0017.000000T0000Z-210512T2300Z/
Washington CO-Logan CO-Phillips CO-
456 PM MDT Wed May 12 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WASHINGTON...
SOUTHEASTERN LOGAN AND SOUTHWESTERN PHILLIPS COUNTIES WILL EXPIRE AT
500 PM MDT...
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire. However small hail and gusty winds are still
possible with this thunderstorm.
LAT...LON 4044 10278 4035 10278 4035 10280 4021 10280
4045 10301 4058 10287 4044 10245
TIME...MOT...LOC 2255Z 311DEG 22KT 4035 10278
$$
RodriguezThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 4:23 PM MDT | Special Weather Statement | BOU | Logan | 52 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.