Alert archive / Colorado / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 157, NWS Denver/Boulder, CO

October 12, 2021Logan County, Phillips County, Sedgwick County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Oct 12, 2021, 5:18 PM MDT for Logan County, Phillips County, Sedgwick County, Colorado. It was in force for 42 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, 5:18 PM MDT (23:18 UTC)
Expired
Oct 12, 2021, 6:00 PM MDT
In force
42 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO

The radar

The Goodland radar (KGLD), 169 km from the middle of the area, began a volume at 23:20 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, 11.3 hours before the alert went out and 99 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.

847 
WUUS55 KBOU 122318
SVRBOU
COC075-095-115-130000-
/O.NEW.KBOU.SV.W.0157.211012T2318Z-211013T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
518 PM MDT Tue Oct 12 2021

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Eastern Logan County in northeastern Colorado...
  Western Phillips County in northeastern Colorado...
  Western Sedgwick County in northeastern Colorado...

* Until 600 PM MDT.

* At 517 PM MDT, severe thunderstorms were located along a line
  extending from 3 miles south of Iliff to 11 miles northeast of
  Yuma, or along a line extending from 8 miles northeast of Sterling
  to 25 miles northwest of Wray, moving north at 45 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
           vehicles is expected.

* Severe thunderstorms will be near...
  Iliff, Padroni and Proctor around 525 PM MDT.

Other locations in the path of these severe thunderstorms include
Peetz, Highland Center, Haxtun, Paoli, Fairfield and Marks Butte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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

&&

LAT...LON 4044 10237 4044 10278 4070 10316 4100 10322
      4100 10238
TIME...MOT...LOC 2317Z 184DEG 41KT 4072 10308 4027 10264 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MEIER
3 follow-up statements
242 
WWUS55 KBOU 122335
SVSBOU

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

COC075-095-115-130000-
/O.CON.KBOU.SV.W.0157.000000T0000Z-211013T0000Z/
Logan CO-Phillips CO-Sedgwick CO-
535 PM MDT Tue Oct 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM MDT
FOR NORTHEASTERN LOGAN...WESTERN PHILLIPS AND WESTERN SEDGWICK
COUNTIES...

At 535 PM MDT, severe thunderstorms were located along a line
extending from 6 miles south of Peetz to 7 miles south of Highland
Center, or along a line extending from 18 miles north of Sterling to
20 miles southwest of Holyoke, moving north at 45 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
         vehicles is expected.

Locations impacted include...
  Haxtun, Paoli, Fairfield, Marks Butte and Sedgwick.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4044 10237 4044 10264 4076 10288 4100 10309
      4100 10238
TIME...MOT...LOC 2335Z 184DEG 41KT 4087 10307 4042 10263 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MEIER
716 
WWUS55 KBOU 122348
SVSBOU

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

COC075-122357-
/O.CAN.KBOU.SV.W.0157.000000T0000Z-211013T0000Z/
Logan CO-
548 PM MDT Tue Oct 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LOGAN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4044 10237 4045 10259 4073 10264 4100 10265
      4100 10238
TIME...MOT...LOC 2347Z 196DEG 44KT 4107 10278 4045 10236 

$$

COC095-115-130000-
/O.CON.KBOU.SV.W.0157.000000T0000Z-211013T0000Z/
Phillips CO-Sedgwick CO-
548 PM MDT Tue Oct 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM MDT
FOR WESTERN PHILLIPS AND WESTERN SEDGWICK COUNTIES...

At 547 PM MDT, severe thunderstorms were located along a line
extending from 6 miles south of Sunol to 9 miles south of Holyoke, or
along a line extending from 11 miles southeast of Sidney to 26 miles
north of Wray, moving north at 50 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
         vehicles is expected.

Locations impacted include...
Haxtun, Ovid, Sedgwick, Paoli, Highland Center, Fairfield and Marks
Butte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4044 10237 4045 10259 4073 10264 4100 10265
      4100 10238
TIME...MOT...LOC 2347Z 196DEG 44KT 4107 10278 4045 10236 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MEIER
434 
WWUS55 KBOU 130001
SVSBOU

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

COC095-115-130010-
/O.EXP.KBOU.SV.W.0157.000000T0000Z-211013T0000Z/
Phillips CO-Sedgwick CO-
601 PM MDT Tue Oct 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN PHILLIPS AND WESTERN
SEDGWICK COUNTIES HAS EXPIRED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been allowed to expire. However, a 
Tornado Warning is effect until 630 PM MDT for eastern Phillips 
county. 

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

LAT...LON 4044 10237 4045 10259 4073 10264 4100 10265
      4100 10238
TIME...MOT...LOC 0000Z 184DEG 41KT 4115 10277 4053 10235 

$$

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, 5:54 PM MDTTornado WarningBOUPhillips36 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.