Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 70, NWS Denver/Boulder, CO

June 13, 2021Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 13, 2021, 6:58 PM MDT for Weld County, Colorado. It was in force for 32 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jun 13, 2021, 6:58 PM MDT (00:58 UTC)
Expired
Jun 13, 2021, 7:30 PM MDT
In force
32 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), 61 km from the middle of the area, began a volume at 00:59 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.

What was reported inside it

TimeReportWhereRemark
Jun 13, 7:10 PM MDTHAIL 1La Salle, CO
Jun 13, 7:15 PM MDTHAIL 1.51 Nnw Milliken, CO
Jun 13, 7:17 PM MDTHAIL 1.251 Sw Evans, CO
Jun 13, 7:22 PM MDTHAIL 1.25Milliken, COESTIMATED BETWEEN QUARTER AND GOLF BALL SIZED HAIL FALLING AT THE TIME OF REPORT.
Jun 13, 7:27 PM MDTHAIL 1.251 Nnw Milliken, COREPORT VIA TWITTER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.0 hours before the alert went out and 138 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 2021-06-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1095 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 2021-06-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 km3 km6 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
1095 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
2628 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

202 
WUUS55 KBOU 140058
SVRBOU
COC123-140130-
/O.NEW.KBOU.SV.W.0070.210614T0058Z-210614T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
658 PM MDT Sun Jun 13 2021

The National Weather Service in Denver Colorado has issued a

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

* Until 730 PM MDT.

* At 658 PM MDT, a severe thunderstorm was located near LaSalle, or 7
  miles south of Greeley, moving north at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Greeley, Evans, Johnstown, Milliken, LaSalle, Kersey, Gilcrest and
  Milton Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4026 10492 4044 10488 4040 10447 4020 10453
TIME...MOT...LOC 0058Z 198DEG 7KT 4031 10474 

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

SCHLATTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 13, 6:17 PM MDTSpecial Weather StatementBOUBroomfield28 min
Jun 13, 6:26 PM MDTSpecial Weather StatementBOUDenver34 min
Jun 13, 6:31 PM MDTSevere Thunderstorm WarningBOUWeld29 min
Jun 13, 6:43 PM MDTSevere Thunderstorm WarningBOUWeld47 min
Jun 13, 7:26 PM MDTSevere Thunderstorm WarningBOULarimer, Weld34 min
Jun 13, 7:32 PM MDTSpecial Weather StatementBOULogan43 min
Jun 13, 8:29 PM MDTSpecial Weather StatementBOUMorgan46 min
Jun 13, 8:31 PM MDTSpecial Weather StatementBOULarimer29 min
Jun 13, 9:32 PM MDTSpecial Weather StatementBOUWeld28 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.