Alert archive / Idaho / Red Flag Warnings in 2021

Red Flag Warning 25, NWS Pocatello, ID

August 29, 202115 counties in Idaho

NWS Pocatello, ID issued this red flag warning at Aug 29, 2021, 1:10 PM MDT for 15 counties in Idaho. It took effect at Aug 30, 2021, 12:00 PM MDT. It was in force for 9 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
Aug 29, 2021, 1:10 PM MDT (19:10 UTC)
In effect from
Aug 30, 2021, 12:00 PM MDT
Expired
Aug 30, 2021, 9:00 PM MDT
In force
9 hr
Issued by
NWS Pocatello, ID

Counties Bingham County, ID, Blaine County, ID, Boise County, ID, Bonneville County, ID, Butte County, ID, Clark County, ID, Custer County, ID, Fremont County, ID, Jefferson County, ID, Jerome County, ID, Lincoln County, ID, Madison County, ID, Minidoka County, ID, Power County, ID, Teton County, ID

The radar

The Pocatello radar (KSFX), 55 km from the middle of the area, began a volume at 19:13 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, 7.2 hours before the alert went out and 258 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 2021-08-29Temperature 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 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
3166 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

603 
WWUS85 KPIH 291910
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
110 PM MDT Sun Aug 29 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT MONDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 410,
422 AND 425...

IDZ410-422-425-301115-
/O.NEW.KPIH.FW.W.0025.210830T1800Z-210831T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
110 PM MDT Sun Aug 29 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT MONDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 410,
422 AND 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 noon to 9 PM MDT Monday.

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF and Fire Weather Zone 425 Middle 
  Snake River Valley/Twin Falls BLM north of the Snake River.

* WINDS...Southwest 10 to 20 mph with gusts up to 35 mph.

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

* IMPACTS...The combination of wind, low humidity, and Haines
  index of 6 could create critical fire conditions. 

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.

&&

$$
3 follow-up statements
870 
WWUS85 KPIH 300809
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
209 AM MDT Mon Aug 30 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT TODAY FOR 
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 410, 
422 AND 425...

IDZ410-422-425-302100-
/O.CON.KPIH.FW.W.0025.210830T1800Z-210831T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
209 AM MDT Mon Aug 30 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT
THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONES 410, 422 AND 425...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF and Fire Weather Zone 425 Middle 
  Snake River Valley/Twin Falls BLM north of the Snake River.

* WINDS...Southwest 10 to 20 mph with gusts up to 35 mph.

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

* IMPACTS...The combination of wind, low humidity, and Haines 
  index of 6 could create critical fire conditions.

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.

&&

$$
546 
WWUS85 KPIH 302026
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
226 PM MDT Mon Aug 30 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT TODAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 410,
422 AND 425...

IDZ410-422-425-310300-
/O.CON.KPIH.FW.W.0025.000000T0000Z-210831T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
226 PM MDT Mon Aug 30 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES
410, 422 AND 425...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM, Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF and Fire Weather Zone 425 Middle 
  Snake River Valley/Twin Falls BLM north of the Snake River.

* WINDS...Southwest 10 to 20 mph with gusts up to 35 mph.

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

* IMPACTS...The combination of wind, low humidity, and Haines 
  index of 6 could create critical fire conditions.

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.

&&

$$
007 
WWUS85 KPIH 310249
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
849 PM MDT Mon Aug 30 2021

IDZ410-422-425-310400-
/O.EXP.KPIH.FW.W.0025.000000T0000Z-210831T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
849 PM MDT Mon Aug 30 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR 
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 410, 
422 AND 425...

Winds have decreased below and relative humidities have increased
above critical fire weather thresholds. Red Flag conditions have
ended for the day.

$$

KSmith

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.