Alert archive / Idaho / Red Flag Warnings in 2021

Red Flag Warning 33, NWS Pocatello, ID

September 16, 202120 counties in Idaho

NWS Pocatello, ID issued this red flag warning at Sep 16, 2021, 1:35 PM MDT for 20 counties in Idaho. It took effect at Sep 17, 2021, 1:00 PM MDT. It was in force for 32 hr. 41 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 16, 2021, 1:35 PM MDT (19:35 UTC)
In effect from
Sep 17, 2021, 1:00 PM MDT
Expired
Sep 18, 2021, 9:00 PM MDT
In force
32 hr
Issued by
NWS Pocatello, ID

Counties Bingham County, ID, Blaine County, ID, Boise County, ID, Bonneville County, ID, Butte County, ID, Cassia County, ID, Clark County, ID, Custer County, ID, Fremont County, ID, Idaho County, ID, Jefferson County, ID, Jerome County, ID, Lemhi County, ID, Lincoln County, ID, Madison County, ID, Minidoka County, ID, Power County, ID, Teton County, ID, Twin Falls County, ID, Valley County, ID

The radar

The Pocatello radar (KSFX), 86 km from the middle of the area, began a volume at 19:36 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.

What was reported inside it

TimeReportWhereRemark
Sep 18, 6:40 AM MDTNON-TSTM WND GST 5011 Wsw Atomic City, IDMESONET STATION SUM BIG SOUTHERN BUTTE.
Sep 18, 12:26 PM MDTNON-TSTM WND GST 4111 N Ellis, IDMESONET STATION EZRI1 EZRA CREEK.
Sep 18, 12:45 PM MDTNON-TSTM WND GST 4214 Ese Hollister, IDMESONET STATION TGFI1 TRAIL GULCH.
Sep 18, 1:08 PM MDTNON-TSTM WND GST 462 Nw Idaho Falls, IDASOS STATION KIDA IDAHO FALLS REGIONAL AIRPORT.
Sep 18, 1:26 PM MDTNON-TSTM WND GST 4611 N Ellis, IDMESONET STATION EZRI1 EZRA CREEK.
Sep 18, 2:30 PM MDTNON-TSTM WND GST 50Atomic City, IDMESONET STATION ATO ATOMIC CITY.
Sep 18, 2:33 PM MDTNON-TSTM WND GST 401 S Mccall, IDASOS STATION KMYL MCCALL.
Sep 18, 2:35 PM MDTNON-TSTM WND GST 404 S Salmon, IDKSMN AIRPORT AWOS.
Sep 18, 2:45 PM MDTNON-TSTM WND GST 5517 Wnw Custer, IDMESONET STATION TT032 IRAWS 1.
Sep 18, 2:50 PM MDTNON-TSTM WND GST 443 Sw Salmon, IDSALMON RAWS.
Sep 18, 2:52 PM MDTNON-TSTM WND GST 4415 E Mackay Bar, IDLODGEPOLE RAWS.
Sep 18, 3:00 PM MDTNON-TSTM WND GST 464 Wsw Galena, IDMESONET STATION SVT 3.8 W GALENA (UUNET).
Sep 18, 3:00 PM MDTNON-TSTM WND GST 489 Ssw Mud Lake, IDMESONET STATION ROV 9 SSW MUD LAKE.
Sep 18, 3:00 PM MDTNON-TSTM WND GST 491 Ne Aberdeen, IDMESONET STATION ABE 1 NE ABERDEEN.
Sep 18, 3:07 PM MDTTSTM WND GST 542 Nw Idaho Falls, IDASOS STATION KIDA IDAHO FALLS REGIONAL AIRPORT.
Sep 18, 3:10 PM MDTNON-TSTM WND GST 453 W Taber, IDMESONET STATION TAB 3 W TABER.
Sep 18, 3:15 PM MDTNON-TSTM WND GST 451 Nnw Craters Of Moon, IDMESONET STATION CRA 1 NNW CRATERS OF THE MOON.
Sep 18, 3:20 PM MDTTSTM WND GST 581 S Michaud, IDPOCATELLO REGIONAL AIRPORT. CONVECTIVE OUTFLOW WINDS.
Sep 18, 3:20 PM MDTTSTM WND GST 591 S Michaud, IDPOCATELLO REGIONAL AIRPORT. CONVECTIVE OUTFLOW WINDS. GUST CORRECTED FROM 58 MPH TO 59 MPH.
Sep 18, 3:20 PM MDTNON-TSTM WND GST 459 E Butte City, IDMESONET STATION DEA DEAD MAN CANYON.
Sep 18, 3:30 PM MDTNON-TSTM WND GST 461 Nnw Craters Of Moon, IDMESONET STATION CRA 1 NNW CRATERS OF THE MOON.
Sep 18, 3:35 PM MDTNON-TSTM WND GST 4611 Wsw Monteview, IDMESONET STATION LOF INL SPECIFIC MANUFACTURING.
Sep 18, 3:45 PM MDTNON-TSTM WND GST 4818 Nne Berenice, IDMESONET STATION BLU BLUE DOME.
Sep 18, 3:50 PM MDTNON-TSTM WND GST 459 E Butte City, IDMESONET STATION DEA DEAD MAN CANYON.
Sep 18, 4:00 PM MDTTSTM WND GST 521 Ese Palisades, IDRWIS ITDE1. US-26 AT PALISADES RESERVOIR. DECAYING THUNDERSTORM OUTFLOW.
Sep 18, 4:00 PM MDTNON-TSTM WND GST 4611 W Osgood, IDMESONET STATION KET KETTLE BUTTE.
Sep 18, 4:00 PM MDTNON-TSTM WND GST 481 Nnw Craters Of Moon, IDMESONET STATION CRA 1 NNW CRATERS OF THE MOON.
Sep 18, 4:05 PM MDTNON-TSTM WND GST 457 S Howe, IDMESONET STATION BAS BASE OF HOWE PEAK.
Sep 18, 4:08 PM MDTNON-TSTM WND GST 414 Ssw Horseshoe Bend, IDMESONET STATION EW2058 HORSESHOE BEND.
Sep 18, 4:09 PM MDTNON-TSTM WND GST 4817 Wsw Marion, IDMESONET STATION CRII1 COTTON RIDGE.
Sep 18, 4:10 PM MDTNON-TSTM WND GST 459 E Butte City, IDMESONET STATION DEA DEAD MAN CANYON.
Sep 18, 4:18 PM MDTNON-TSTM WND GST 414 Ssw Horseshoe Bend, IDMESONET STATION EW2058 HORSESHOE BEND.
Sep 18, 4:20 PM MDTNON-TSTM WND GST 5213 Ne Atomic City, IDMESONET STATION EBR INL MATERIALS FUELS COMPLEX.
Sep 18, 4:25 PM MDTNON-TSTM WND GST 472 Nne Sugar City, IDMESONET STATION SUG 2 NNE SUGAR CITY.
Sep 18, 4:25 PM MDTNON-TSTM WND GST 501 Nnw Craters Of Moon, IDMESONET STATION CRA 1 NNW CRATERS OF THE MOON.
Sep 18, 4:45 PM MDTNON-TSTM WND GST 4914 Ese Hollister, IDMESONET STATION TGFI1 TRAIL GULCH.
Sep 18, 4:51 PM MDTNON-TSTM WND GST 566 Se North Fork, IDMESONET STATION KRCI1 KRILEY CREEK RAWS.
Sep 18, 5:51 PM MDTNON-TSTM WND GST 606 Se North Fork, IDMESONET STATION KRCI1 KRILEY CREEK RAWS.
Sep 18, 6:48 PM MDTNON-TSTM WND GST 486 E Yellowjacket, IDMESONET STATION BAEI1 RED ROCK PEAK.
Sep 18, 6:51 PM MDTNON-TSTM WND GST 4311 Wsw Shoup, IDMESONET STATION SKFI1 SKULL GULCH.
Sep 18, 6:55 PM MDTNON-TSTM WND GST 586 S Twin Falls, IDASOS STATION KTWF TWIN FALLS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Boise Airport, ID (KBOI), launched 12:00Z, 7.6 hours before the alert went out and 224 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 2021-09-16Temperature 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 2021-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -168 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
2777 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
-168 m²/s²
0-3 km storm-relative helicity
-80 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

014 
WWUS85 KPIH 161935
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
135 PM MDT Thu Sep 16 2021

IDZ425-171100-
/O.NEW.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
/O.CON.KPIH.FW.W.0032.210916T2000Z-210917T0200Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
135 PM MDT Thu Sep 16 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE WEATHER 
ZONE 425... 
...RED FLAG WARNING IN EFFECT FROM 1 PM TO 9 PM MDT 
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONE 425...

The National Weather Service in Pocatello has issued a Red Flag
Warning for gusty winds and low relative humidity, which is in
effect from 1 PM to 9 PM MDT Saturday.

* AFFECTED AREA...Fire Weather Zone 425 Middle Snake River 
  Valley/Twin Falls BLM north of the Snake River.

* WINDS...Southwest 15 to 25 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 11 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ411-422-475-476-171100-
/O.NEW.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
135 PM MDT Thu Sep 16 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM FRIDAY TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONES 411, 422, 475 AND 476...

The National Weather Service in Pocatello has issued a Red Flag
Warning for gusty winds and low relative humidity, which is in
effect from 1 PM Friday to 9 PM MDT Saturday.

* AFFECTED AREA...Fire Weather Zone 411 Centennial Mountains and 
  Snake River Range/Targhee NF, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF, Fire Weather Zone 475 East Salmon 
  River Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and 
  Lost River Range/Challis NF.

* WINDS...Southwest 20 to 30 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ410-171100-
/O.NEW.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
135 PM MDT Thu Sep 16 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM FRIDAY TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 410...

The National Weather Service in Pocatello has issued a Red Flag
Warning for gusty winds and low relative humidity, which is in
effect from 1 PM Friday to 9 PM MDT Saturday.

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM.

* WINDS...Southwest 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ427-171100-
/O.NEW.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
135 PM MDT Thu Sep 16 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM TO 9 PM MDT SATURDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE WEATHER ZONE
427...

The National Weather Service in Pocatello has issued a Red Flag
Warning for gusty winds and low relative humidity, which is in
effect from 1 PM to 9 PM MDT Saturday.

* AFFECTED AREA...Fire Weather Zone 427 Goose Creek and Raft 
  River Valley/Southern Sawtooth NF/Twin Falls BLM south of the 
  Snake River.

* WINDS...Southwest 20 to 25 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 14 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$
5 follow-up statements
242 
WWUS85 KPIH 170147
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
747 PM MDT Thu Sep 16 2021

...TODAY'S RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING 
FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 
425...

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM FRIDAY TO 9 PM
MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONES 410, 411, 422, 475 AND 476...

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 425 AND 427...

IDZ425-171100-
/O.EXP.KPIH.FW.W.0032.000000T0000Z-210917T0200Z/
/O.CON.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
747 PM MDT Thu Sep 16 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 425...

* AFFECTED AREA...Fire Weather Zone 425 Middle Snake River 
  Valley/Twin Falls BLM north of the Snake River.

* WINDS...Southwest 15 to 25 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 11 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ411-422-475-476-171100-
/O.CON.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
747 PM MDT Thu Sep 16 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM FRIDAY TO 9 PM
MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONES 411, 422, 475 AND 476...

* AFFECTED AREA...Fire Weather Zone 411 Centennial Mountains and 
  Snake River Range/Targhee NF, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF, Fire Weather Zone 475 East Salmon 
  River Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and 
  Lost River Range/Challis NF.

* WINDS...Southwest 20 to 30 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ410-171100-
/O.CON.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
747 PM MDT Thu Sep 16 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM FRIDAY TO 9 PM
MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 410...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM.

* WINDS...Southwest 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ427-171100-
/O.CON.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
747 PM MDT Thu Sep 16 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 427...

* AFFECTED AREA...Fire Weather Zone 427 Goose Creek and Raft 
  River Valley/Southern Sawtooth NF/Twin Falls BLM south of the 
  Snake River.

* WINDS...Southwest 20 to 25 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 14 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$
645 
WWUS85 KPIH 170836
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
236 AM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM FRIDAY TO 9 PM 
MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE 
WEATHER ZONES 410, 411, 422, 475 AND 476...

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 425 AND 427...

IDZ411-422-475-476-180300-
/O.CON.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
236 AM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO
9 PM MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR
FIRE WEATHER ZONES 411, 422, 475 AND 476...

* AFFECTED AREA...Fire Weather Zone 411 Centennial Mountains and 
  Snake River Range/Targhee NF, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF, Fire Weather Zone 475 East Salmon 
  River Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and 
  Lost River Range/Challis NF.

* WINDS...Southwest 20 to 30 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ410-180300-
/O.CON.KPIH.FW.W.0033.210917T1900Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
236 AM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO
9 PM MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR
FIRE WEATHER ZONE 410...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM.

* WINDS...Southwest 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ425-427-180300-
/O.CON.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
236 AM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONE 427...

* AFFECTED AREA...Fire Weather Zone 425 Middle Snake River 
  Valley/Twin Falls BLM north of the Snake River and Fire 
  Weather Zone 427 Goose Creek and Raft River Valley/Southern 
  Sawtooth NF/Twin Falls BLM south of the Snake River.

* WINDS...Southwest 20 to 25 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 14 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

Messick

$$
827 
WWUS85 KPIH 171936
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
136 PM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM FRIDAY TO 9 PM
MDT SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONES 410, 411, 422, 475 AND 476...

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONE 425 AND 427...

IDZ411-422-475-476-181200-
/O.CON.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
136 PM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT SATURDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE WEATHER 
ZONES 411, 422, 475 AND 476...

* AFFECTED AREA...Fire Weather Zone 411 Centennial Mountains and 
  Snake River Range/Targhee NF, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF, Fire Weather Zone 475 East Salmon 
  River Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and 
  Lost River Range/Challis NF.

* WINDS...Southwest 20 to 30 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 10 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ410-181200-
/O.CON.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
136 PM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT SATURDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE WEATHER ZONE
410...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM.

* WINDS...South 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 11 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

$$

IDZ425-427-181200-
/O.CON.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
136 PM MDT Fri Sep 17 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONES 425 AND 427...

* AFFECTED AREA...Fire Weather Zone 425 Middle Snake River 
  Valley/Twin Falls BLM north of the Snake River and Fire 
  Weather Zone 427 Goose Creek and Raft River Valley/Southern 
  Sawtooth NF/Twin Falls BLM south of the Snake River.

* WINDS...Southwest 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.

- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.

&&

Messick

$$
188 
WWUS85 KPIH 180741
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
141 AM MDT Sat Sep 18 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT 
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE 
WEATHER ZONES 410, 411, 422, 475 AND 476...

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM TO 9 PM MDT
SATURDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE
WEATHER ZONE 425 AND 427...

IDZ411-422-475-476-190300-
/O.CON.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
141 AM MDT Sat Sep 18 2021

...RED FLAG WARNING REMAINS IN EFFECT TODAY 1 PM TO 9 PM MDT THIS
EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR IDAHO FIRE 
WEATHER ZONES 411, 422, 475 AND 476...

* AFFECTED AREA...Fire Weather Zone 411 Centennial Mountains and 
  Snake River Range/Targhee NF, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF, Fire Weather Zone 475 East Salmon 
  River Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and 
  Lost River Range/Challis NF.

* WINDS...Southwest 20 to 30 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 10 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates. In heavier fuels, fire intensity will be greater.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

&&

$$

IDZ410-190300-
/O.CON.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
141 AM MDT Sat Sep 18 2021

...RED FLAG WARNING REMAINS IN EFFECT TODAY FROM 1 PM UNTIL 9 PM 
MDT THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR 
IDAHO FIRE WEATHER ZONE 410...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM.

* WINDS...South 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 11 percent.

* IMPACTS...Should a fire get established, expect rapid fire 
  spread rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

&&

$$

IDZ425-427-190300-
/O.CON.KPIH.FW.W.0033.210918T1900Z-210919T0300Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
141 AM MDT Sat Sep 18 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO
9 PM MDT THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY
FOR IDAHO FIRE WEATHER ZONES 425 AND 427...

* AFFECTED AREA...Fire Weather Zone 425 Middle Snake River 
  Valley/Twin Falls BLM north of the Snake River and Fire 
  Weather Zone 427 Goose Creek and Raft River Valley/Southern 
  Sawtooth NF/Twin Falls BLM south of the Snake River.

* WINDS...Southwest 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Should a fire get established, expect rapid fire
  spread rates. In heavier fuels, expect more intense fire
  activity.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:

- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.

&&

Messick

$$
406 
WWUS85 KPIH 190256
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
856 PM MDT Sat Sep 18 2021

IDZ411-422-475-476-190400-
/O.EXP.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Centennial Mountains and Snake River Range/Targhee NF-
Sawtooth Range/Northern Sawtooth NF-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
856 PM MDT Sat Sep 18 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 411, 422, 
475 AND 476...

Humidity has risen above 15 percent. Will continue to see some
gusty winds through Sunday with the elevated humidity.  

$$

IDZ410-190400-
/O.EXP.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
856 PM MDT Sat Sep 18 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 410...

Humidity has risen above 15 percent. Will continue to see some
gusty winds through Sunday with the elevated humidity. 

$$

IDZ425-427-190400-
/O.EXP.KPIH.FW.W.0033.000000T0000Z-210919T0300Z/
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
856 PM MDT Sat Sep 18 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 425 AND 
427...

Humidity has risen above 15 percent. Will continue to see some
gusty winds through Sunday with the elevated humidity. 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 2:59 AM MDTRed Flag WarningPIHBlaine, Butte, Jerome, Lincoln, Minidoka, Power17 hr

Nearby

Red Flag Warnings in Idaho, 2021Every red flag 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.