Alert archive / Wyoming / Freeze Warnings in 2021

Freeze Warning 1, NWS Cheyenne, WY

September 19, 2021Albany County, Carbon County, Wyoming

NWS Cheyenne, WY issued this freeze warning at Sep 19, 2021, 1:48 PM MDT for Albany County, Carbon County, Wyoming. It took effect at Sep 20, 2021, 1:00 AM MDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 19, 2021, 1:48 PM MDT (19:48 UTC)
In effect from
Sep 20, 2021, 1:00 AM MDT
Expired
Sep 20, 2021, 8:00 AM MDT
In force
7 hr
Issued by
NWS Cheyenne, WY

Counties Albany County, WY, Carbon County, WY

The radar

The Cheyenne radar (KCYS), 140 km from the middle of the area, began a volume at 19:50 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 nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 7.8 hours before the alert went out and 230 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, Riverton, WY at 12:00Z on 2021-09-19Temperature 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, Riverton, WY at 12:00Z on 2021-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.1939587897Sfc1 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
2037 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

120 
WWUS75 KCYS 191948
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
148 PM MDT Sun Sep 19 2021

WYZ112-114-201200-
/O.NEW.KCYS.FZ.W.0001.210920T0700Z-210920T1400Z/
Sierra Madre Range-Snowy Range-
Including the cities of Centennial and Albany
148 PM MDT Sun Sep 19 2021

...FREEZE WARNING IN EFFECT FROM 1 AM TO 8 AM MDT MONDAY...

* WHAT...Sub-freezing temperatures as low as 27 expected.

* WHERE...Sierra Madre Range and Snowy Range.

* WHEN...From 1 AM to 8 AM MDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing. If recreating outdoors, be sure to have the proper
  clothing for the freezing temperatures.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

WYZ110-201200-
/O.NEW.KCYS.FZ.A.0001.210921T0700Z-210921T1400Z/
/O.CON.KCYS.HW.W.0032.000000T0000Z-210920T0300Z/
North Snowy Range Foothills-
Including the cities of Arlington and Elk Mountain
148 PM MDT Sun Sep 19 2021

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS
EVENING...
...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

* WHAT...For the High Wind Warning, west winds 30 to 40 mph with
  gusts 50 to 60 mph. For the Freeze Watch, sub-freezing 
  temperatures as low as 30 possible.

* WHERE...North Snowy Range Foothills.

* WHEN...For the High Wind Warning, until 9 PM MDT this evening. 
  For the Freeze Watch, from late Monday night through Tuesday 
  morning.

* IMPACTS...Travel will be difficult, especially for high profile
  vehicles. Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing. If recreating outdoors, be sure to have the proper 
  clothing for the freezing temperatures. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

WYZ103>105-109-111-113-115-116-201200-
/O.NEW.KCYS.FZ.A.0001.210921T0700Z-210921T1400Z/
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Carbon County-Southwest Carbon County-
Upper North Platte River Basin-Laramie Valley-South Laramie Range-
Including the cities of Garrett, Esterbrook, Seminoe Dam, 
Medicine Bow, Shirley Basin, Rawlins, Baggs, Saratoga, 
Encampment, Laramie, Bosler, Buford, Pumpkin Vine, and Vedauwoo
148 PM MDT Sun Sep 19 2021

...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

* WHAT...Sub-freezing temperatures as low as 30 possible.

* WHERE...North Laramie Range, Ferris/Seminoe/Shirley Mountains, 
  Shirley Basin, Central Carbon County, Southwest Carbon County, 
  Upper North Platte River Basin, Laramie Valley and South 
  Laramie Range.

* WHEN...From late Monday night through Tuesday morning.

* IMPACTS...Frost and freeze conditions will kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing. If recreating outdoors, be sure to have the proper
  clothing for the freezing temperatures.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$
2 follow-up statements
930 
WWUS75 KCYS 200234
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
834 PM MDT Sun Sep 19 2021

WYZ110-201045-
/O.EXP.KCYS.HW.W.0032.000000T0000Z-210920T0300Z/
/O.CON.KCYS.FZ.A.0001.210921T0700Z-210921T1400Z/
North Snowy Range Foothills-
Including the cities of Arlington and Elk Mountain
834 PM MDT Sun Sep 19 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE MONDAY NIGHT THROUGH
TUESDAY MORNING...
...HIGH WIND WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING...

* WHAT...Sub-freezing temperatures as low as 29 possible.

* WHERE...North Snowy Range Foothills.

* WHEN...From late Monday night through Tuesday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

WYZ112-114-201045-
/O.CON.KCYS.FZ.W.0001.210920T0700Z-210920T1400Z/
Sierra Madre Range-Snowy Range-
Including the cities of Centennial and Albany
834 PM MDT Sun Sep 19 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 1 AM TO 8 AM MDT
MONDAY...

* WHAT...Sub-freezing temperatures as low as 27 expected.

* WHERE...Snowy Range and Sierra Madre Range.

* WHEN...From 1 AM to 8 AM MDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

WYZ103>105-109-111-113-115-116-201045-
/O.CON.KCYS.FZ.A.0001.210921T0700Z-210921T1400Z/
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Carbon County-Southwest Carbon County-
Upper North Platte River Basin-Laramie Valley-South Laramie Range-
Including the cities of Garrett, Esterbrook, Seminoe Dam, 
Medicine Bow, Shirley Basin, Rawlins, Baggs, Saratoga, 
Encampment, Laramie, Bosler, Buford, Pumpkin Vine, and Vedauwoo
834 PM MDT Sun Sep 19 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE MONDAY NIGHT THROUGH
TUESDAY MORNING...

* WHAT...Sub-freezing temperatures as low as 29 possible.

* WHERE...Shirley Basin, South Laramie Range, 
  Ferris/Seminoe/Shirley Mountains, Laramie Valley, Upper North 
  Platte River Basin, North Laramie Range, Southwest Carbon 
  County and Central Carbon County.

* WHEN...From late Monday night through Tuesday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$
276 
WWUS75 KCYS 200926
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
326 AM MDT Mon Sep 20 2021

WYZ112-114-201400-
/O.CON.KCYS.FZ.W.0001.000000T0000Z-210920T1400Z/
Sierra Madre Range-Snowy Range-
Including the cities of Centennial and Albany
326 AM MDT Mon Sep 20 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM MDT THIS MORNING...

* WHAT...Sub-freezing temperatures as low as 27 degrees expected.

* WHERE...Snowy Range and Sierra Madre Range.

* WHEN...Until 8 AM MDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

WYZ103>105-109>111-113-115-116-210000-
/O.CON.KCYS.FZ.A.0001.210921T0700Z-210921T1400Z/
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Upper North Platte River Basin-
Laramie Valley-South Laramie Range-
Including the cities of Garrett, Esterbrook, Seminoe Dam, 
Medicine Bow, Shirley Basin, Rawlins, Arlington, Elk Mountain, 
Baggs, Saratoga, Encampment, Laramie, Bosler, Buford, 
Pumpkin Vine, and Vedauwoo
326 AM MDT Mon Sep 20 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
TUESDAY MORNING...

* WHAT...Sub-freezing temperatures as low as 29 degrees possible.

* WHERE...Portions of southeast Wyoming along and west of the
  Laramie Range, including but not limited to Laramie, Rawlins,
  and Saratoga. 

* WHEN...From late Monday night through Tuesday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 12:56 AM MDTHigh Wind WarningCYSAlbany, Carbon20 hr
Sep 19, 1:48 PM MDTFreeze WatchCYSAlbany, Carbon, Converse, Laramie, Platte24 hr

Nearby

Freeze Warnings in Wyoming, 2021Every freeze 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.