Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 39, NWS Denver/Boulder, CO

May 22, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 22, 2021, 3:25 PM MDT for Weld County, Colorado. It was in force for 35 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 22, 2021, 3:25 PM MDT (21:25 UTC)
Expired
May 22, 2021, 4:00 PM MDT
In force
35 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 Denver radar (KFTG), 46 km from the middle of the area, began a volume at 21:28 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
May 22, 12:20 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.4 hours before the alert went out and 94 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 2021-05-22Temperature 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 2021-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
1528 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

138 
WUUS55 KBOU 222125
SVRBOU
COC123-222200-
/O.NEW.KBOU.SV.W.0039.210522T2125Z-210522T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
325 PM MDT Sat May 22 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  South central Weld County in northeastern Colorado...

* Until 400 PM MDT.

* At 325 PM MDT, a severe thunderstorm was located near Prospect
  Valley, or 30 miles southeast of Greeley, moving northeast at 20
  mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Prospect Valley and Roggen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM MDT for northeastern
Colorado.

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

&&

LAT...LON 4019 10415 4015 10415 4001 10431 4006 10450
      4029 10441
TIME...MOT...LOC 2125Z 218DEG 18KT 4009 10437 

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

DANIELSON

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:18 PM MDTSpecial Weather StatementBOUMorgan27 min
May 21, 10:57 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick48 min
May 22, 1:11 PM MDTSevere Thunderstorm WarningBOUAdams, Logan, Morgan, Washington49 min
May 22, 1:28 PM MDTTornado Warning Tornado observedBOUMorgan17 min
May 22, 1:45 PM MDTTornado WarningBOUMorgan15 min
May 22, 1:54 PM MDTTornado Warning Tornado observedBOUMorgan, Washington36 min
May 22, 1:56 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert28 min
May 22, 1:58 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington33 min
May 22, 2:05 PM MDTTornado WarningBOUAdams, Arapahoe25 min
May 22, 2:18 PM MDTSpecial Weather StatementBOUAdams42 min
May 22, 2:43 PM MDTTornado WarningBOULogan17 min
May 22, 2:46 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick44 min
May 22, 2:57 PM MDTSevere Thunderstorm WarningBOULogan, Sedgwick48 min
May 22, 3:01 PM MDTTornado WarningBOULogan29 min
May 22, 3:16 PM MDTTornado WarningBOULincoln29 min
May 22, 3:48 PM MDTTornado WarningBOUElbert, Lincoln27 min
May 22, 3:53 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld26 min
May 22, 4:13 PM MDTTornado Warning Tornado observedBOUElbert, Lincoln32 min
May 22, 4:42 PM MDTTornado Warning Tornado observedBOUElbert, Lincoln33 min
May 22, 5:16 PM MDTTornado WarningBOUElbert, Lincoln29 min
May 22, 5:27 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln33 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.