Alert archive / Idaho / Freeze Warnings in 2021

Freeze Warning 4, NWS Pocatello, ID

September 29, 202112 counties in Idaho

NWS Pocatello, ID issued this freeze warning at Sep 29, 2021, 9:58 AM MDT for 12 counties in Idaho. It took effect at Sep 30, 2021, 1:00 AM MDT. It was in force for 8 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 29, 2021, 9:58 AM MDT (15:58 UTC)
In effect from
Sep 30, 2021, 1:00 AM MDT
Expired
Sep 30, 2021, 9:25 AM MDT
In force
8 hr
Issued by
NWS Pocatello, ID

Counties Bannock County, ID, Bingham County, ID, Blaine County, ID, Bonneville County, ID, Butte County, ID, Cassia County, ID, Fremont County, ID, Jefferson County, ID, Lincoln County, ID, Madison County, ID, Minidoka County, ID, Power County, ID

The radar

The Pocatello radar (KSFX), 18 km from the middle of the area, began a volume at 15:56 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

Boise Airport, ID (KBOI), launched 12:00Z, 4.0 hours before the alert went out and 280 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, Boise Airport, ID at 12:00Z on 2021-09-29Temperature 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 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Boise Airport, ID at 12:00Z on 2021-09-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1395 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

364 
WWUS75 KPIH 291558
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
958 AM MDT Wed Sep 29 2021

IDZ051>055-301200-
/O.CAN.KPIH.FZ.W.0003.000000T0000Z-210929T1600Z/
/O.NEW.KPIH.FZ.W.0004.210930T0700Z-210930T1600Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper Snake River Plain-
Lower Snake River Plain-Eastern Magic Valley-
Including the cities of Shoshone, Richfield, Carey, Mud Lake, 
INL, Craters of the Moon NM, Idaho Falls, Rexburg, St. Anthony, 
Pocatello, Blackfoot, American Falls, Shelley, Fort Hall, Burley,
Rupert, Heyburn, and Oakley
958 AM MDT Wed Sep 29 2021

...FREEZE WARNING IN EFFECT FROM 1 AM TO 10 AM MDT THURSDAY...

* WHAT...Sub-freezing temperatures as low as 24 especially across
  the Upper Snake and Arco Desert. In the lower Snake Plain and
  Magic Valley sub-freezing temperatures as low as 27. 

* WHERE...Upper and Lower Snake River Plain, Arco Desert, and 
  the Eastern Magic Valley.

* WHEN...From 1 AM to 10 AM MDT Thursday.

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

* ADDITIONAL DETAILS...Overnight low temperatures tonight will
  likely result in a prolonged, hard-freeze, especially across the
  Upper Snake and Arco Desert, resulting in a season ending 
  freeze event for the growing region. 
  

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.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
2 follow-up statements
753 
WWUS75 KPIH 300742
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
142 AM MDT Thu Sep 30 2021

IDZ051>055-301600-
/O.CON.KPIH.FZ.W.0004.000000T0000Z-210930T1600Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper Snake River Plain-
Lower Snake River Plain-Eastern Magic Valley-
Including the cities of Shoshone, Richfield, Carey, Mud Lake, 
INL, Craters of the Moon NM, Idaho Falls, Rexburg, St. Anthony, 
Pocatello, Blackfoot, American Falls, Shelley, Fort Hall, Burley,
Rupert, Heyburn, and Oakley
142 AM MDT Thu Sep 30 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 10 AM MDT THIS
MORNING...

* WHAT...Sub-freezing temperatures as low as 24 especially 
  across the Upper Snake and Arco Desert. In the lower Snake 
  Plain and Magic Valley sub-freezing temperatures as low as 27.

* WHERE...Upper and Lower Snake River Plain, Arco Desert, and 
  the Eastern Magic Valley.

* WHEN...Through 10 AM MDT Today.

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

* ADDITIONAL DETAILS...Overnight low temperatures tonight will 
  likely result in a prolonged, hard-freeze, especially across 
  the Upper Snake and Arco Desert, resulting in a season ending 
  freeze event for the growing region.

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.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
947 
WWUS75 KPIH 301525
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
925 AM MDT Thu Sep 30 2021

IDZ051>055-301630-
/O.CAN.KPIH.FZ.W.0004.000000T0000Z-210930T1600Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper Snake River Plain-
Lower Snake River Plain-Eastern Magic Valley-
Including the cities of Shoshone, Richfield, Carey, Mud Lake, 
INL, Craters of the Moon NM, Idaho Falls, Rexburg, St. Anthony, 
Pocatello, Blackfoot, American Falls, Shelley, Fort Hall, Burley,
Rupert, Heyburn, and Oakley
925 AM MDT Thu Sep 30 2021

...FREEZE WARNING IS CANCELLED...

Temperatures have risen above freezing and will continue to rise
through the morning, therefore the freeze warning is being
canceled at this time. The last two mornings of prolonged sub-
freezing temperatures have resulted in an end to the official 
growing season. Therefore, no more frost/freeze products will be 
issued this year.

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello

Nearby

Freeze Warnings in Idaho, 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.