Alert archive / Colorado / Tornado Warnings in 2021

Tornado Warning 41, NWS Denver/Boulder, CO

October 12, 2021Phillips County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Oct 12, 2021, 5:54 PM MDT for Phillips County, Colorado. It was in force for 36 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
Oct 12, 2021, 5:54 PM MDT (23:54 UTC)
Expired
Oct 12, 2021, 6:30 PM MDT
In force
36 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

County Phillips County, CO

The radar

The Goodland radar (KGLD), 141 km from the middle of the area, began a volume at 23:57 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
Oct 12, 2:46 PM MDTTornado WatchSPC7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.9 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 2021-10-12Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-10-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 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
1285 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
335 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

467 
WFUS55 KBOU 122354
TORBOU
COC095-130030-
/O.NEW.KBOU.TO.W.0041.211012T2354Z-211013T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
554 PM MDT Tue Oct 12 2021

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Eastern Phillips County in northeastern Colorado...

* Until 630 PM MDT.
    
* At 554 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 9 miles south of Holyoke, moving north at 50 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...
  Holyoke around 605 PM MDT.

Other locations in the path of this tornadic thunderstorm include
Amherst.

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 4044 10242 4074 10236 4075 10205 4044 10205
TIME...MOT...LOC 2354Z 195DEG 44KT 4045 10231 

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

$$

MEIER
2 follow-up statements
317 
WWUS55 KBOU 130016
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
616 PM MDT Tue Oct 12 2021

COC095-130030-
/O.CON.KBOU.TO.W.0041.000000T0000Z-211013T0030Z/
Phillips CO-
616 PM MDT Tue Oct 12 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR EASTERN
PHILLIPS COUNTY...
    
At 615 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Pleasant Valley, or 8 miles east of Holyoke, moving
northeast at 35 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...
  Amherst.

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 4044 10223 4074 10222 4075 10205 4044 10205
TIME...MOT...LOC 0015Z 215DEG 30KT 4055 10215 

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

$$

MEIER
201 
WWUS55 KBOU 130027
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
627 PM MDT Tue Oct 12 2021

COC095-130036-
/O.EXP.KBOU.TO.W.0041.000000T0000Z-211013T0030Z/
Phillips CO-
627 PM MDT Tue Oct 12 2021

...THE TORNADO WARNING FOR EASTERN PHILLIPS COUNTY WILL EXPIRE AT 630
PM MDT...
                
The storm which prompted the warning has moved out of the area, and 
no longer appears capable of producing a tornado. Therefore, the 
warning will be allowed to expire.

A Tornado Watch remains in effect until 1000 PM MDT for northeastern
Colorado.

LAT...LON 4044 10223 4074 10222 4075 10205 4044 10205
TIME...MOT...LOC 0026Z 195DEG 44KT 4066 10211 

$$

MEIER

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 12, 3:56 AM MDTHigh Wind WatchBOUBoulder, Larimer11 hr
Oct 12, 3:56 AM MDTHigh Wind WarningBOUArapahoe, Douglas, Elbert, Lincoln14 hr
Oct 12, 2:47 PM MDTHigh Wind WarningBOUBoulder, Larimer, Logan, Phillips, Sedgwick, Weld24 hr
Oct 12, 5:05 PM MDTSpecial Weather StatementBOULogan25 min
Oct 12, 5:18 PM MDTSevere Thunderstorm WarningBOULogan, Phillips, Sedgwick42 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.