Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 12, NWS Missoula, MT

August 4, 20215 counties in Idaho; 13 counties in Montana

NWS Missoula, MT issued this red flag warning at Aug 4, 2021, 12:21 PM PDT for 5 counties in Idaho; 13 counties in Montana. It took effect at Aug 5, 2021, 8:00 AM PDT. It was in force for 15 hr. 6 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
Aug 4, 2021, 12:21 PM PDT (19:21 UTC)
In effect from
Aug 5, 2021, 8:00 AM PDT
Expired
Aug 5, 2021, 11:00 PM PDT
In force
15 hr
Issued by
NWS Missoula, MT

Counties Clearwater County, ID, Idaho County, ID, Latah County, ID, Lewis County, ID, Nez Perce County, ID, Beaverhead County, MT, Deer Lodge County, MT, Flathead County, MT, Granite County, MT, Jefferson County, MT, Lewis and Clark County, MT, Madison County, MT, Mineral County, MT, Missoula County, MT, Powell County, MT, Ravalli County, MT, Sanders County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 61 km from the middle of the area, began a volume at 19:23 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
Aug 5, 1:47 PM PDTTSTM WND GST 5110 Wsw Grant, MTMESONET STATION BRRM8 BRENNER RAWS.
Aug 5, 2:58 PM PDTTSTM WND GST 485 Ene Dillon, MTASOS STATION KDLN DILLON AIRPORT.
Aug 5, 3:08 PM PDTTSTM WND GST 563 Sse Butte, MTASOS STATION KBTM BUTTE-MOONEY AP.
Aug 5, 4:39 PM PDTTSTM WND GST 542 E Helena, MTASOS STATION KHLN HELENA AIRPORT.
Aug 5, 4:50 PM PDTTSTM WND GST 632 E Helena, MTASOS STATION KHLN HELENA AIRPORT.
Aug 5, 5:28 PM PDTNON-TSTM WND GST 638 Ssw Wolf Creek, MTMESONET STATION MTSBN 8.4 S WOLF CREEK (MT DOT).

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

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 7.4 hours before the alert went out and 216 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, Spokane, WA at 12:00Z on 2021-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 joules per kilogram.LCLLFCEL10008507005003002001001 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, Spokane, WA at 12:00Z on 2021-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 square meters per square second.193958Sfc1 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
18 J/kg
Mixed-layer CIN
-391 J/kg
Mixed-layer LCL
2638 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
259 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

628 
WWUS85 KMSO 041921
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
121 PM MDT Wed Aug 4 2021

IDZ102-103-060600-
/O.NEW.KMSO.FW.W.0012.210805T1500Z-210806T0600Z/
Palouse/Hells Canyon-Clearwater/Nez Perce-
1221 PM PDT Wed Aug 4 2021

...RED FLAG WARNING IN EFFECT FROM 8 AM TO 11 PM PDT THURSDAY...

* Affected area: Fire Zone 102 (Palouse/Hells Canyon). Fire Zone 103
  (Clearwater/Nez Perce). 

* Impacts: Dangerous conditions due to strong and erratic outflow
  winds along with new fire starts are possible, particularly for
  areas that did not see significant rainfall over the last few 
  days. 

* Thunderstorms: A mix of wet and dry storms will develop in the
  morning, with several waves of storms possible into Thursday 
  evening.

* Outflow Winds: Widespread outflow winds of 25-40 mph are
  anticipated. Stronger storms could produce winds up to 50 mph. 

&&

$$

MTZ106-108>111-060600-
/O.NEW.KMSO.FW.W.0012.210805T1800Z-210806T0600Z/
West Lolo-East Lolo-Bitterroot-Deerlodge/West Beaverhead-
East Beaverhead-
121 PM MDT Wed Aug 4 2021

...RED FLAG WARNING IN EFFECT FROM NOON THURSDAY TO MIDNIGHT MDT
THURSDAY NIGHT...

* Affected area: Fire Zone 106 (West Lolo). Fire Zone 108 (East 
  Lolo). Fire Zone 109 (Bitterroot). Fire Zone 110 
  (Deerlodge/West Beaverhead). Fire Zone 111 (East Beaverhead). 

* Impacts: Dangerous conditions due to strong and erratic outflow
  winds along with new fire starts are possible, particularly for
  areas that did not see significant rainfall over the last few 
  days. 

* Thunderstorms: A mix of wet and dry storms will develop in the
  early afternoon, with several waves of storms possible into 
  Thursday evening.

* Outflow Winds: Widespread outflow winds of 25-40 mph are
  anticipated. Stronger storms could produce winds over 50 mph. 


&&

$$
1 follow-up statement
628 
WWUS85 KMSO 060544
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
1144 PM MDT Thu Aug 5 2021

IDZ102-103-060645-
/O.EXP.KMSO.FW.W.0012.000000T0000Z-210806T0600Z/
Palouse/Hells Canyon-Clearwater/Nez Perce-
1044 PM PDT Thu Aug 5 2021

...RED FLAG WARNING WILL EXPIRE AT 11 PM PDT THIS EVENING...

* Affected area: Fire Zone 102 (Palouse/Hells Canyon). Fire Zone 
  103 (Clearwater/Nez Perce). 


&&

$$

MTZ106-108>111-060645-
/O.EXP.KMSO.FW.W.0012.000000T0000Z-210806T0600Z/
West Lolo-East Lolo-Bitterroot-Deerlodge/West Beaverhead-
East Beaverhead-
1144 PM MDT Thu Aug 5 2021

...RED FLAG WARNING WILL EXPIRE AT MIDNIGHT MDT TONIGHT...

* Affected area: Fire Zone 106 (West Lolo). Fire Zone 108 (East 
  Lolo). Fire Zone 109 (Bitterroot). Fire Zone 110 
  (Deerlodge/West Beaverhead). Fire Zone 111 (East Beaverhead). 

&&

$$

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 3, 7:55 PM PDTSpecial Weather StatementMSO65 min
Aug 4, 2:57 PM PDTSpecial Weather StatementMSOPowell48 min
Aug 4, 4:30 PM PDTSpecial Weather StatementMSOFlathead30 min
Aug 4, 4:35 PM PDTSpecial Weather StatementMSOLake25 min
Aug 4, 4:50 PM PDTSpecial Weather StatementMSOLake25 min
Aug 4, 4:55 PM PDTSpecial Weather StatementMSOFlathead35 min

Nearby

Red Flag Warnings in Montana, 2021Red 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.