Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 20, NWS Denver/Boulder, CO

May 14, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 14, 2021, 6:49 PM MDT for Weld County, Colorado. It was in force for 41 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 14, 2021, 6:49 PM MDT (00:49 UTC)
Expired
May 14, 2021, 7:30 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 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 00:50 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, 0.8 hours before the alert went out and 153 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 00:00Z on 2021-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 137 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2021-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
137 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
1940 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

835 
WUUS55 KBOU 150049
SVRBOU
COC123-150130-
/O.NEW.KBOU.SV.W.0020.210515T0049Z-210515T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
649 PM MDT Fri May 14 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Northwestern Weld County in northeastern Colorado...

* Until 730 PM MDT.

* At 648 PM MDT, a severe thunderstorm was located 7 miles northeast
  of Rockport, or 15 miles southeast of Cheyenne, moving southeast at
  25 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...
  Grover and Rockport. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4085 10408 4073 10479 4100 10481 4100 10448
TIME...MOT...LOC 0048Z 302DEG 23KT 4095 10467 

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

DIRENZO
1 follow-up statement
632 
WWUS55 KBOU 150108
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
708 PM MDT Fri May 14 2021

COC123-150130-
/O.CON.KBOU.SV.W.0020.000000T0000Z-210515T0130Z/
Weld CO-
708 PM MDT Fri May 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM MDT
FOR NORTH CENTRAL WELD COUNTY...

At 708 PM MDT, a severe thunderstorm was located 13 miles southwest
of Hereford, or 23 miles southeast of Cheyenne, moving southeast at
25 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...
Grover.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4075 10467 4098 10468 4100 10448 4085 10408
TIME...MOT...LOC 0108Z 302DEG 23KT 4088 10452 

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

DIRENZO

The office that day

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

IssuedProductOfficeCountiesLasted
May 14, 6:52 PM MDTSpecial Weather StatementBOUMorgan38 min
May 14, 7:17 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington28 min
May 14, 7:36 PM MDTSevere Thunderstorm WarningBOUWeld39 min
May 14, 7:40 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington50 min
May 14, 8:14 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld46 min
May 14, 8:52 PM MDTSevere Thunderstorm WarningBOUMorgan38 min
May 14, 9:29 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington46 min
May 15, 2:21 PM MDTSpecial Weather StatementBOULarimer24 min
May 15, 2:50 PM MDTSpecial Weather StatementBOUDenver25 min
May 15, 5:29 PM MDTSpecial Weather StatementBOUDouglas31 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.