Alert archive / Idaho / Red Flag Warnings in 2021
Red Flag Warning 21, NWS Pocatello, ID
NWS Pocatello, ID issued this red flag warning at Jul 23, 2021, 12:54 AM MDT for Butte County, Custer County, Lemhi County, Idaho. It took effect at Jul 23, 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
- Jul 23, 2021, 12:54 AM MDT (06:54 UTC)
- In effect from
- Jul 23, 2021, 12:00 PM MDT
- Expired
- Jul 23, 2021, 9:00 PM MDT
- In force
- 9 hr
- Issued by
- NWS Pocatello, ID
Counties Butte County, ID, Custer County, ID, Lemhi County, ID
The radar
The Pocatello radar (KSFX), 160 km from the middle of the area, began a volume at 06:55 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, 6.9 hours before the alert went out and 209 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3332 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- -7 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
067 WWUS85 KPIH 230654 RFWPIH URGENT - FIRE WEATHER MESSAGE National Weather Service Pocatello ID 1254 AM MDT Fri Jul 23 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 ZONE 476... IDZ476-232100- /O.NEW.KPIH.FW.W.0021.210723T1800Z-210724T0300Z/ Lemhi and Lost River Range/Challis NF- 1254 AM MDT Fri Jul 23 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 ZONE 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 noon today to 9 PM MDT this evening. * AFFECTED AREA...Fire Weather Zone 476 Lemhi and Lost River Range/Challis NF. * WINDS...West 10 to 20 mph with gusts up to 35 mph. * RELATIVE HUMIDITY...8 to 16 percent. * IMPACTS...The combination of wind, low humidity and or lightning will 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. && $$
2 follow-up statements
172 WWUS85 KPIH 232014 RFWPIH URGENT - FIRE WEATHER MESSAGE National Weather Service Pocatello ID 214 PM MDT Fri Jul 23 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 476... IDZ476-240300- /O.CON.KPIH.FW.W.0021.000000T0000Z-210724T0300Z/ Lemhi and Lost River Range/Challis NF- 214 PM MDT Fri Jul 23 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 476... * AFFECTED AREA...Fire Weather Zone 476 covering the Lemhi and Lost River Range and Challis National Forest. * WINDS...West 10 to 20 MPH with gusts up to 30 MPH. * RELATIVE HUMIDITY...8 to 16 percent. * IMPACTS...The combination of wind and low humidity will create critical fire conditions. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly based on any one or more of these criteria for Southeastern Idaho: - Relative humidity at or below 15 percent combined with wind gusts of at least 25 MPH in the mountains, or at least 30 MPH in the Snake Plain. - Thunderstorm coverage of 25 percent or greater, without specific rainfall criteria. - Other high impact events deemed critical by the National Weather Service and area fire management agencies. && $$
555 WWUS85 KPIH 240250 RFWPIH URGENT - FIRE WEATHER MESSAGE National Weather Service Pocatello ID 850 PM MDT Fri Jul 23 2021 IDZ476-240400- /O.EXP.KPIH.FW.W.0021.000000T0000Z-210724T0300Z/ Lemhi and Lost River Range/Challis NF- 850 PM MDT Fri Jul 23 2021 ...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONE 476... Wind gusts are subsiding and relative humidity is starting to recover, so the Red Flag Warning will be allowed to expire at 9 PM MDT. $$
The office that day
Everything else NWS Pocatello, ID issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 22, 7:19 PM MDT | Special Weather Statement | PIH | Bear Lake, Caribou, Franklin | 56 min |
| Jul 23, 3:50 PM MDT | Special Weather Statement | PIH | Bear Lake, Franklin, Oneida | 40 min |
| Jul 23, 4:32 PM MDT | Special Weather Statement | PIH | Franklin | 58 min |
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.