Alert archive / Colorado / Tornado Warnings in 2023

Tornado Warning 39, NWS Denver/Boulder, CO

June 21, 2023Logan County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 21, 2023, 5:41 PM MDT for Logan County, Colorado. It was in force for 19 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
Jun 21, 2023, 5:41 PM MDT (23:41 UTC)
Expired
Jun 21, 2023, 6:00 PM MDT
In force
19 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

County Logan County, CO

The radar

The Denver radar (KFTG), 130 km from the middle of the area, began a volume at 23:43 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
Jun 21, 12:33 PM MDTTornado WatchSPC7 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.7 hours before the alert went out and 245 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1238 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2023-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 196 square meters per square second.1939Sfc1 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
1238 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
834 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
196 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.6
Supercell composite
8.0

Open this sounding in Storm Lab

The text

As transmitted.

410 
WFUS55 KBOU 212341
TORBOU
COC075-220000-
/O.NEW.KBOU.TO.W.0039.230621T2341Z-230622T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
541 PM MDT Wed Jun 21 2023

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Southwestern Logan County in northeastern Colorado...

* Until 600 PM MDT.
    
* At 540 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Willard, or 12 miles west of Sterling, moving east
  at 15 mph.

  HAZARD...Tornado and ping pong ball size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Logan Corners and Atwood around 600 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4058 10321 4048 10344 4052 10347 4052 10349
      4053 10356 4060 10356 4069 10351 4074 10340
TIME...MOT...LOC 2340Z 248DEG 15KT 4057 10342 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.50 IN

$$

DANIELSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 9:32 AM MDTFlood WatchBOUAdams, Arapahoe, Douglas, Elbert, Lincoln, Washington20 hr
Jun 21, 1:17 PM MDTSevere Thunderstorm WarningBOULogan43 min
Jun 21, 1:48 PM MDTSpecial Weather StatementBOULogan42 min
Jun 21, 1:53 PM MDTSevere Thunderstorm WarningBOULogan52 min
Jun 21, 1:59 PM MDTSevere Thunderstorm WarningBOUWashington46 min
Jun 21, 2:22 PM MDTSevere Thunderstorm Warning Considerable damage threatBOULogan23 min
Jun 21, 2:36 PM MDTSevere Thunderstorm WarningBOULogan, Washington19 min
Jun 21, 2:39 PM MDTSevere Thunderstorm WarningBOUWashington36 min
Jun 21, 2:42 PM MDTSevere Thunderstorm WarningBOULogan33 min
Jun 21, 3:09 PM MDTSevere Thunderstorm Warning Considerable damage threatBOULogan36 min
Jun 21, 3:11 PM MDTSevere Thunderstorm WarningBOUWashington34 min
Jun 21, 3:24 PM MDTFlash Flood WarningBOULogan3 hr
Jun 21, 3:33 PM MDTTornado WarningBOULogan27 min
Jun 21, 3:38 PM MDTAreal Flood AdvisoryBOUWashington3 hr
Jun 21, 3:42 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUWashington33 min
Jun 21, 3:51 PM MDTTornado Warning Tornado observedBOULogan, Morgan, Washington24 min
Jun 21, 3:53 PM MDTSevere Thunderstorm Warning Considerable damage threatBOULogan37 min
Jun 21, 4:01 PM MDTSevere Thunderstorm WarningBOUWeld29 min
Jun 21, 4:02 PM MDTAreal Flood AdvisoryBOULogan, Morgan, Washington3 hr
Jun 21, 4:05 PM MDTTornado WarningBOUWashington25 min
Jun 21, 4:21 PM MDTTornado WarningBOUWashington24 min
Jun 21, 4:22 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan, Washington23 min
Jun 21, 4:23 PM MDTSevere Thunderstorm WarningBOUWeld37 min
Jun 21, 4:37 PM MDTTornado Warning Tornado observedConsiderable damage threatBOUWashington23 min
Jun 21, 4:42 PM MDTFlash Flood WarningBOUMorgan, Washington3 hr
Jun 21, 4:45 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan45 min
Jun 21, 4:46 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Washington29 min
Jun 21, 4:47 PM MDTTornado WarningBOUMorgan, Weld28 min
Jun 21, 4:54 PM MDTTornado Warning Tornado observedConsiderable damage threatBOUWashington21 min
Jun 21, 4:55 PM MDTSevere Thunderstorm WarningBOULincoln35 min
Jun 21, 5:07 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Weld38 min
Jun 21, 5:10 PM MDTTornado Warning Tornado observedConsiderable damage threatBOUWashington35 min
Jun 21, 5:13 PM MDTTornado WarningBOULogan17 min
Jun 21, 5:16 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan44 min
Jun 21, 5:25 PM MDTTornado WarningBOULogan20 min
Jun 21, 5:27 PM MDTTornado WarningBOUMorgan, Washington33 min
Jun 21, 5:28 PM MDTSevere Thunderstorm WarningBOUWashington32 min
Jun 21, 5:45 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington30 min
Jun 21, 5:52 PM MDTTornado Warning Tornado observedConsiderable damage threatBOUWashington23 min
Jun 21, 5:54 PM MDTSevere Thunderstorm WarningBOULogan36 min
Jun 21, 5:54 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson36 min
Jun 21, 5:59 PM MDTAreal Flood AdvisoryBOULarimer3 hr

Nearby

Tornado Warnings in Colorado, 2023Every tornado warning in 2023Tornadoes in 2023

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.