Alert archive / Idaho / Frost Advisories in 2021

Frost Advisory 9, NWS Pocatello, ID

September 19, 202112 counties in Idaho

NWS Pocatello, ID issued this frost advisory at Sep 19, 2021, 2:11 AM MDT for 12 counties in Idaho. It took effect at Sep 20, 2021, 3:00 AM MDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Sep 19, 2021, 2:11 AM MDT (08:11 UTC)
In effect from
Sep 20, 2021, 3:00 AM MDT
Expired
Sep 20, 2021, 9:00 AM MDT
In force
6 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 08:12 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 00:00Z, 8.2 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 00:00Z 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 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 00:00Z on 2021-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -209 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
2068 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
-209 m²/s²
0-3 km storm-relative helicity
-1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

836 
WWUS75 KPIH 190811
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
211 AM MDT Sun Sep 19 2021

IDZ051>055-192130-
/O.NEW.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
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
211 AM MDT Sun Sep 19 2021

...FROST ADVISORY IN EFFECT FROM 3 AM TO 9 AM MDT MONDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...From the eastern Magic Valley, including Shoshone and
  Burley, to the northern end of the Snake River plain, including
  Rexburg and Saint Anthony. This also includes the cities of
  American Falls, Pocatello, Chubbuck, Blackfoot, Idaho Falls, and
  Rigby.

* WHEN...From 3 AM to 9 AM MDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
4 follow-up statements
665 
WWUS75 KPIH 191446
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
846 AM MDT Sun Sep 19 2021

IDZ054-192100-
/O.NEW.KPIH.LW.Y.0028.210919T1800Z-210920T0200Z/
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Lower Snake River Plain-
Including the cities of Pocatello, Blackfoot, American Falls, 
Shelley, and Fort Hall
846 AM MDT Sun Sep 19 2021

...LAKE WIND ADVISORY IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS
EVENING...
...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

* WHAT...For the Lake Wind Advisory, southwest winds 20 to 25 mph
  with gusts up to 35 mph expected. For the Frost Advisory, 
  temperatures as low as 35 will result in frost formation. 

* WHERE...American Falls Reservoir for the Lake Wind Advisory. The
  Lower Snake River Plain for the Frost Advisory, mostly impacting
  those areas northwest of American Falls Reservoir including
  American Falls, Aberdeen, and the Rockford areas.

* WHEN...For the Lake Wind Advisory, from noon today to 8 PM MDT
  this evening. For the Frost Advisory, from 3 AM to 9 AM MDT 
  Monday. 
 
* IMPACTS...Strong winds and rough waves on area lakes will create
  hazardous boating conditions for small water-craft. Frost could
  kill sensitive outdoor vegetation if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on area lakes should use extra caution since strong winds
and rough waves can overturn small craft.

Take steps now to protect tender plants from the cold.

&&

$$

IDZ051>053-055-192100-
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper 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, 
Burley, Rupert, Heyburn, and Oakley
846 AM MDT Sun Sep 19 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Eastern Magic Valley, Shoshone Desert, Mud Lake Desert,
  and the Upper Snake River Plain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
157 
WWUS75 KPIH 191912
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
112 PM MDT Sun Sep 19 2021

IDZ054-200200-
/O.CON.KPIH.LW.Y.0028.000000T0000Z-210920T0200Z/
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Lower Snake River Plain-
Including the cities of Pocatello, Blackfoot, American Falls, 
Shelley, and Fort Hall
112 PM MDT Sun Sep 19 2021

...LAKE WIND ADVISORY REMAINS IN EFFECT UNTIL 8 PM MDT THIS
EVENING...
...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

* WHAT...For the Lake Wind Advisory, southwest winds 20 to 25 mph
  with gusts up to 35 mph expected. For the Frost Advisory,
  temperatures as low as 34 will result in frost formation.

* WHERE...American Falls Reservoir for the Lake Wind Advisory. The
  Lower Snake River Plain for the Frost Advisory, mostly impacting
  those areas northwest of Interstate corridor including American
  Falls, Aberdeen, and the Rockford areas.

* WHEN...For the Lake Wind Advisory, continuing until 8 PM MDT 
  this evening. For the Frost Advisory, from 3 AM to 9 AM MDT 
  Monday.

* IMPACTS...Strong winds and rough waves on area lakes will create
  hazardous boating conditions for small water-craft. Frost can
  kill or damage sensitive outdoor vegetation if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on area lakes should use extra caution since strong winds
and rough waves can overturn small craft.

Take steps now to protect tender plants from the cold.

&&

$$

IDZ051>053-055-200200-
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper 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, 
Burley, Rupert, Heyburn, and Oakley
112 PM MDT Sun Sep 19 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Eastern Magic Valley, Shoshone Desert, Mud Lake 
  Desert, and the Upper Snake River Plain.

* WHEN...Monday morning from 3 AM to 9 AM MDT.

* IMPACTS...Frost can kill or damage sensitive outdoor vegetation
  if left uncovered. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
059 
WWUS75 KPIH 200154
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
754 PM MDT Sun Sep 19 2021

IDZ054-201500-
/O.EXP.KPIH.LW.Y.0028.000000T0000Z-210920T0200Z/
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Lower Snake River Plain-
Including the cities of Pocatello, Blackfoot, American Falls, 
Shelley, and Fort Hall
754 PM MDT Sun Sep 19 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

...LAKE WIND ADVISORY WILL EXPIRE AT 8 PM MDT THIS EVENING...

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...American Falls Reservoir for the Lake Wind Advisory. 
  The Lower Snake River Plain for the Frost Advisory, mostly 
  impacting those areas northwest of Interstate corridor 
  including American Falls, Aberdeen, and the Rockford areas.

* WHEN...For the Lake Wind Advisory, continuing until 8 PM MDT 
  this evening. For the Frost Advisory, from 3 AM to 9 AM MDT 
  Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

IDZ051>053-055-201500-
/O.CON.KPIH.FR.Y.0009.210920T0900Z-210920T1500Z/
Shoshone/Lava Beds-Arco/Mud Lake Desert-Upper 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, 
Burley, Rupert, Heyburn, and Oakley
754 PM MDT Sun Sep 19 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM MDT
MONDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Eastern Magic Valley, Shoshone Desert, Mud Lake 
  Desert, and the Upper Snake River Plain.

* WHEN...Monday morning from 3 AM to 9 AM MDT.

* IMPACTS...Frost can kill or damage sensitive outdoor 
  vegetation if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
886 
WWUS75 KPIH 201500
NPWPIH

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
900 AM MDT Mon Sep 20 2021

IDZ051>055-201600-
/O.EXP.KPIH.FR.Y.0009.000000T0000Z-210920T1500Z/
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
900 AM MDT Mon Sep 20 2021

...FROST ADVISORY WILL EXPIRE AT 9 AM MDT THIS MORNING...

Temperature have begun to warm into the upper 30s and 40s across
the warned area, thus the Frost Advisory will be allowed to expire
at 9 AM MDT.

$$

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

The office that day

Everything else NWS Pocatello, ID issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 8:46 AM MDTLake Wind AdvisoryPIHBannock, Bingham, Power11 hr
Sep 19, 11:16 AM MDTSpecial Weather StatementPIHMinidoka59 min
Sep 19, 12:07 PM MDTSpecial Weather StatementPIHCassia, Power53 min

Nearby

Frost Advisories in Idaho, 2021Every frost advisory 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.