Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 3, NWS Denver/Boulder, CO

April 27, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Apr 27, 2021, 1:59 PM MDT for Weld County, Colorado. It was in force for 31 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
Apr 27, 2021, 1:59 PM MDT (19:59 UTC)
Expired
Apr 27, 2021, 2:30 PM MDT
In force
31 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), 84 km from the middle of the area, began a volume at 20:01 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.

IssuedProductOfficeLasted
Apr 27, 11:45 AM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.0 hours before the alert went out and 113 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 2021-04-27Temperature 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 2021-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.1939587897117Sfc1 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
3214 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

181 
WUUS55 KBOU 271959
SVRBOU
COC123-272030-
/O.NEW.KBOU.SV.W.0003.210427T1959Z-210427T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
159 PM MDT Tue Apr 27 2021

The National Weather Service in Denver Colorado has issued a

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

* Until 230 PM MDT.

* At 158 PM MDT, a severe thunderstorm was located near Keota, or 32
  miles northwest of Fort Morgan, moving north at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected. Hail may accumulate on 
           roadways causing hazardous travel.

* Locations impacted include...
  Pawnee Buttes and Keota. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4060 10386 4059 10415 4086 10424 4088 10387
TIME...MOT...LOC 1958Z 175DEG 9KT 4068 10404 

HAIL...1.00IN
WIND...<50MPH
 
$$

DANIELSON

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 27, 1:52 AM MDTSevere Thunderstorm WarningBOUWashington23 min
Apr 27, 3:16 AM MDTWinter Storm WarningBOUBoulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more30 hr
Apr 27, 11:35 AM MDTSpecial Weather StatementBOUDouglas25 min
Apr 27, 11:55 AM MDTSpecial Weather StatementBOUElbert50 min
Apr 27, 11:59 AM MDTSpecial Weather StatementBOUDenver31 min
Apr 27, 12:49 PM MDTSevere Thunderstorm WarningBOUAdams, Weld26 min
Apr 27, 1:15 PM MDTSpecial Weather StatementBOUAdams45 min
Apr 27, 1:51 PM MDTSpecial Weather StatementBOULincoln39 min
Apr 27, 1:53 PM MDTSpecial Weather StatementBOUWeld37 min
Apr 27, 2:02 PM MDTSevere Thunderstorm WarningBOUElbert28 min
Apr 27, 2:08 PM MDTWinter Weather AdvisoryBOUClear Creek, Douglas, Gilpin, Jefferson, Park20 hr
Apr 27, 2:23 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln52 min
Apr 27, 2:43 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan32 min
Apr 27, 2:49 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln41 min
Apr 27, 3:00 PM MDTSpecial Weather StatementBOULincoln45 min
Apr 27, 3:10 PM MDTSpecial Weather StatementBOUMorgan20 min
Apr 27, 3:13 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington32 min
Apr 27, 3:28 PM MDTSevere Thunderstorm WarningBOULincoln47 min
Apr 27, 3:32 PM MDTSpecial Weather StatementBOUMorgan28 min
Apr 27, 3:41 PM MDTTornado WarningBOULincoln34 min
Apr 27, 4:12 PM MDTSevere Thunderstorm WarningBOULincoln33 min
Apr 27, 4:16 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington17 min
Apr 27, 4:36 PM MDTTornado WarningBOULincoln24 min
Apr 27, 5:19 PM MDTSevere Thunderstorm WarningBOUWashington26 min
Apr 27, 5:51 PM MDTSpecial Weather StatementBOUPhillips24 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.