Alert archive / Idaho / Red Flag Warnings in 2021

Red Flag Warning 13, NWS Boise, ID

September 5, 2021Idaho County, Valley County, Idaho

NWS Boise, ID issued this red flag warning at Sep 5, 2021, 2:13 PM PDT for Idaho County, Valley County, Idaho. It was in force for 7 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
Sep 5, 2021, 2:13 PM PDT (21:13 UTC)
Expired
Sep 5, 2021, 9:00 PM PDT
In force
7 hr
Issued by
NWS Boise, ID

Counties Idaho County, ID, Valley County, ID

The radar

The Boise radar (KCBX), 210 km from the middle of the area, began a volume at 21:19 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, 9.2 hours before the alert went out and 200 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 2021-09-05Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Boise Airport, ID at 12:00Z on 2021-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
4153 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

050 
WWUS85 KBOI 052113
RFWBOI

URGENT - FIRE WEATHER MESSAGE
National Weather Service Boise ID
313 PM MDT Sun Sep 5 2021

.Dry cold front moving through the area will produce gusty winds
into the evening hours before diminishing.

IDZ402-060400-
/O.NEW.KBOI.FW.W.0013.210905T2113Z-210906T0400Z/
Eastern Payette National Forest-
313 PM MDT Sun Sep 5 2021

...RED FLAG WARNING IN EFFECT UNTIL 10 PM MDT THIS EVENING FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR EASTERN PAYETTE
NATIONAL FOREST...WHICH IS FIRE WEATHER ZONE 402...

The National Weather Service in Boise has issued a Red Flag
Warning, which is in effect until 10 PM MDT this evening. 

* WINDS...Gusts up to 30 mph.

* RELATIVE HUMIDITY...5 to 15 percent.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will occur shortly.

&&

$$


W
1 follow-up statement
015 
WWUS85 KBOI 060331
RFWBOI

URGENT - FIRE WEATHER MESSAGE
National Weather Service Boise ID
931 PM MDT Sun Sep 5 2021

IDZ402-060445-
/O.EXP.KBOI.FW.W.0013.000000T0000Z-210906T0400Z/
Eastern Payette National Forest-
931 PM MDT Sun Sep 5 2021

...RED FLAG WARNING WILL EXPIRE AT 10 PM MDT THIS EVENING FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR EASTERN PAYETTE
NATIONAL FOREST...WHICH IS FIRE WEATHER ZONE 402...

Winds will continue to subside this evening.

$$


W

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.