Alert archive / Colorado / Tornado Warnings in 2021

Tornado Warning 21, NWS Denver/Boulder, CO

May 23, 2021Logan County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 23, 2021, 3:42 PM MDT for Logan County, Colorado. It was in force for 33 min. 7 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
May 23, 2021, 3:42 PM MDT (21:42 UTC)
Expired
May 23, 2021, 4:15 PM MDT
In force
33 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 158 km from the middle of the area, began a volume at 21:43 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.

What was reported inside it

TimeReportWhereRemark
May 23, 3:58 PM MDTHAIL 13 E Atwood, CO
May 23, 4:00 PM MDTTORNADO4 Ese Sterling, COPOWER POLES DOWN ON HIGHWAY 61. LIKELY TORNADO DAMAGE. EXACT LOCATION AND TIME APPROXIMATE.
May 23, 4:00 PM MDTTORNADO4 Ese Sterling, COPOWER POLES DOWN ON HIGHWAY 61. LIKELY TORNADO DAMAGE. EXACT LOCATION AND TIME APPROXIMATE.
May 23, 4:11 PM MDTHAIL 0.75Iliff, COREPORT FROM MPING: DIME (0.75 IN.).
May 23, 4:11 PM MDTHAIL 1Iliff, COREPORT FROM MPING: QUARTER (1.00 IN.).
May 23, 4:15 PM MDTTSTM WND DMGPadroni, COPOWER POLES AND SMALL TREE BRANCHES BLOWN DOWN. TIME ESTIMATED.
May 23, 4:20 PM MDTTORNADO4 W Fleming, COLANDSPOUT LIKELY ON BOUNDARY SOUTH OF MAIN MESOCYCLONE.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 23, 12:06 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.7 hours before the alert went out and 87 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 2021-05-23Temperature 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 2021-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.19395878Sfc1 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
1106 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

417 
WFUS55 KBOU 232142
TORBOU
COC075-232215-
/O.NEW.KBOU.TO.W.0021.210523T2142Z-210523T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
342 PM MDT Sun May 23 2021

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  South central Logan County in northeastern Colorado...

* Until 415 PM MDT.
    
* At 341 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles southeast of Atwood, or 10 miles south of
  Sterling, moving north at 45 mph.

  HAZARD...Tornado and quarter 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.

* Locations impacted include...
  Sterling, Iliff and Padroni. 

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 4075 10287 4044 10304 4044 10329 4082 10317
TIME...MOT...LOC 2141Z 197DEG 38KT 4047 10318 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

DANIELSON
1 follow-up statement
489 
WWUS55 KBOU 232203
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
403 PM MDT Sun May 23 2021

COC075-232215-
/O.CON.KBOU.TO.W.0021.000000T0000Z-210523T2215Z/
Logan CO-
403 PM MDT Sun May 23 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM MDT FOR CENTRAL
LOGAN COUNTY...
    
At 403 PM MDT, a severe thunderstorm capable of producing a tornado
was located 4 miles south of Iliff, or 7 miles northeast of Sterling,
moving north at 45 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.

Locations impacted include...
Sterling, Iliff and Padroni. 

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 4049 10301 4056 10325 4082 10317 4075 10287
TIME...MOT...LOC 2203Z 197DEG 38KT 4070 10309 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

DANIELSON

The office that day

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

IssuedProductOfficeCountiesLasted
May 22, 6:06 PM MDTTornado WarningBOUWashington24 min
May 22, 8:00 PM MDTSpecial Weather StatementBOUPhillips30 min
May 22, 8:29 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick46 min
May 22, 9:37 PM MDTSevere Thunderstorm WarningBOULincoln38 min
May 23, 12:40 PM MDTTornado WarningBOUElbert, Lincoln19 min
May 23, 12:41 PM MDTSpecial Weather StatementBOUWeld49 min
May 23, 12:50 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln40 min
May 23, 1:24 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln36 min
May 23, 1:28 PM MDTSpecial Weather StatementBOUWeld32 min
May 23, 1:47 PM MDTTornado WarningBOUArapahoe, Elbert, Lincoln, Washington28 min
May 23, 2:13 PM MDTTornado WarningBOUWashington32 min
May 23, 2:44 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington31 min
May 23, 2:55 PM MDTTornado WarningBOUWashington20 min
May 23, 3:11 PM MDTTornado WarningBOULogan, Washington34 min
May 23, 3:14 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert, Lincoln, Washington46 min
May 23, 4:06 PM MDTAreal Flood AdvisoryBOUWashington3 hr
May 23, 4:10 PM MDTTornado Warning Tornado observedConsiderable damage threatBOULogan20 min
May 23, 4:27 PM MDTTornado WarningBOULogan23 min
May 23, 4:43 PM MDTTornado WarningBOUWashington17 min
May 23, 4:58 PM MDTTornado WarningBOUWashington17 min
May 23, 5:12 PM MDTAreal Flood AdvisoryBOULogan, Washington104 min
May 23, 5:13 PM MDTSevere Thunderstorm WarningBOULogan, Phillips, Washington32 min
May 23, 5:31 PM MDTTornado WarningBOUWashington14 min

Nearby

Tornado Warnings in Colorado, 2021Every tornado warning in 2021Tornadoes 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.