Alert archive / Idaho / Red Flag Warnings in 2021

Red Flag Warning 26, NWS Pocatello, ID

August 31, 202112 counties in Idaho

NWS Pocatello, ID issued this red flag warning at Aug 31, 2021, 12:49 AM MDT for 12 counties in Idaho. It took effect at Aug 31, 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 31, 2021, 12:49 AM MDT (06:49 UTC)
In effect from
Aug 31, 2021, 12:00 PM MDT
Expired
Aug 31, 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, Madison County, ID, Power County, ID, Teton County, ID

The radar

The Pocatello radar (KSFX), 68 km from the middle of the area, began a volume at 06:46 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, 6.8 hours before the alert went out and 278 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 2021-08-31Temperature 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 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.19395878Sfc1 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
3467 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
132 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

590 
WWUS85 KPIH 310649
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
1249 AM MDT Tue Aug 31 2021

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

IDZ410-422-312100-
/O.NEW.KPIH.FW.W.0026.210831T1800Z-210901T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
1249 AM MDT Tue Aug 31 2021

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

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 today to 9 PM MDT this evening.

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM and Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF.

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

* RELATIVE HUMIDITY...9 to 16 percent.

* IMPACTS..The combination of wind and low humidity potentially
  will cause rapid fire spread with new or existing wildfires. 

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.

&&

$$
2 follow-up statements
000 
WWUS85 KPIH 312023
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
223 PM MDT Tue Aug 31 2021

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

IDZ410-422-010300-
/O.CON.KPIH.FW.W.0026.000000T0000Z-210901T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
223 PM MDT Tue Aug 31 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 AND 422...

* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River 
  Valley/Idaho Falls BLM and Fire Weather Zone 422 Sawtooth 
  Range/Northern Sawtooth NF.

* WINDS...Southwest 10 to 25 mph with gusts up to 35 mph.

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

* IMPACTS..The combination of wind and low humidity potentially 
  will cause rapid fire spread with new or existing wildfires.

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.

&&

$$
544 
WWUS85 KPIH 010307
RFWPIH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
907 PM MDT Tue Aug 31 2021

IDZ410-422-010415-
/O.EXP.KPIH.FW.W.0026.000000T0000Z-210901T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
907 PM MDT Tue Aug 31 2021

...RED FLAG WARNING HAS EXPIRED FOR GUSTY WINDS AND LOW RELATIVE
HUMIDITY FOR FIRE WEATHER ZONES 410 AND 422...

Winds across the warning area have dropped below critical
thresholds. Relative humidity values remain below 15% across
portions of the Arco Desert, but are slowly rising. Therefore, the
warning has been allowed to expire 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.