Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 33, NWS Denver/Boulder, CO

May 21, 2021Morgan County, Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 21, 2021, 3:51 PM MDT for Morgan County, Washington 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
May 21, 2021, 3:51 PM MDT (21:51 UTC)
Expired
May 21, 2021, 4:15 PM MDT
In force
24 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Morgan County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 116 km from the middle of the area, began a volume at 21:53 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, 9.9 hours before the alert went out and 44 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.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3153 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

178 
WUUS55 KBOU 212151
SVRBOU
COC087-121-212215-
/O.NEW.KBOU.SV.W.0033.210521T2151Z-210521T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
351 PM MDT Fri May 21 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Eastern Morgan County in northeastern Colorado...
  North central Washington County in northeastern Colorado...

* Until 415 PM MDT.

* At 350 PM MDT, a severe thunderstorm was located 7 miles east of
  Gary, or 14 miles southwest of Akron, moving north at 50 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
           vehicles is expected.

* Locations impacted include...
  Akron, Brush, Hillrose, Prewitt Reservoir, Snyder and Midway. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4043 10307 3999 10331 4001 10356 4044 10368
TIME...MOT...LOC 2150Z 184DEG 45KT 4006 10345 

HAIL...1.00IN
WIND...60MPH
 
$$

DIRENZO
2 follow-up statements
269 
WWUS55 KBOU 212203
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
403 PM MDT Fri May 21 2021

COC087-121-212215-
/O.CON.KBOU.SV.W.0033.000000T0000Z-210521T2215Z/
Morgan CO-Washington CO-
403 PM MDT Fri May 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM MDT
FOR NORTHEASTERN MORGAN AND NORTH CENTRAL WASHINGTON COUNTIES...

At 403 PM MDT, a severe thunderstorm was located over Midway, or 12
miles northwest of Akron, moving north at 50 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
         vehicles is expected.

Locations impacted include...
Hillrose, Prewitt Reservoir, Snyder and Midway. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4043 10307 4012 10329 4014 10353 4044 10368
TIME...MOT...LOC 2203Z 184DEG 45KT 4023 10343 

HAIL...1.00IN
WIND...60MPH
 
$$

DIRENZO
285 
WWUS55 KBOU 212214
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
414 PM MDT Fri May 21 2021

COC087-121-212224-
/O.EXP.KBOU.SV.W.0033.000000T0000Z-210521T2215Z/
Morgan CO-Washington CO-
414 PM MDT Fri May 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MORGAN AND NORTH
CENTRAL WASHINGTON COUNTIES WILL EXPIRE AT 415 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small hail
is still possible with this thunderstorm.

LAT...LON 4043 10307 4012 10329 4014 10353 4044 10368
TIME...MOT...LOC 2214Z 184DEG 45KT 4033 10342 

$$

DIRENZO

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 7:14 PM MDTSpecial Weather StatementBOULogan31 min
May 20, 7:27 PM MDTSevere Thunderstorm WarningBOULogan, Weld48 min
May 20, 8:15 PM MDTSevere Thunderstorm WarningBOULogan30 min
May 21, 5:30 PM MDTSpecial Weather StatementBOULincoln30 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.