Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 18, NWS Missoula, MT

September 8, 20217 counties in Montana

NWS Missoula, MT issued this red flag warning at Sep 8, 2021, 8:50 PM MDT for 7 counties in Montana. It took effect at Sep 9, 2021, 12:00 PM MDT. It was in force for 9 hr. 5 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
Sep 8, 2021, 8:50 PM MDT (02:50 UTC)
In effect from
Sep 9, 2021, 12:00 PM MDT
Expired
Sep 9, 2021, 9:00 PM MDT
In force
9 hr
Issued by
NWS Missoula, MT

Counties Beaverhead County, MT, Deer Lodge County, MT, Granite County, MT, Jefferson County, MT, Madison County, MT, Powell County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 154 km from the middle of the area, began a volume at 02:49 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
Sep 9, 5:23 PM MDTTSTM WND GST 465 Ene Dillon, MTASOS STATION KDLN DILLON AIRPORT.
Sep 9, 5:35 PM MDTTSTM WND GST 515 Nne Cameron, MTAWOS STATION KEKS ENNIS BIG SKY AWOS.
Sep 9, 5:45 PM MDTTSTM WND GST 518 Ne Bannack, MTBLM ARGENTA MESONET SITE.
Sep 9, 6:00 PM MDTTSTM WND GST 456 S Alder, MTRUBY VALLEY AGRIMET SITE.
Sep 9, 6:18 PM MDTTSTM WND GST 585 Ene Dillon, MTASOS STATION KDLN DILLON AIRPORT.

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

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 2.8 hours before the alert went out and 231 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, Great_falls, MT at 00:00Z on 2021-09-09Temperature 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, Great_falls, MT at 00:00Z on 2021-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 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
3793 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

765 
WWUS85 KMSO 090250
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
850 PM MDT Wed Sep 8 2021

MTZ110-111-100300-
/O.NEW.KMSO.FW.W.0018.210909T1800Z-210910T0300Z/
Deerlodge/West Beaverhead-East Beaverhead-
850 PM MDT Wed Sep 8 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT THURSDAY...

* Affected area: Fire Zone 110 (Deerlodge/West Beaverhead). Fire 
  Zone 111 (East Beaverhead). 

* Impacts: The combination of gusty winds and low humidity along
  with high Haines will result in critical fire weather
  conditions.

* Winds: West 15 to 25 mph with gusts 30 to 40 mph.

* Minimum humidities: 12 to 17 percent.

* Haines Index: 5

&&

$$
1 follow-up statement
170 
WWUS85 KMSO 100238
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
838 PM MDT Thu Sep 9 2021

MTZ110-111-100345-
/O.EXP.KMSO.FW.W.0018.000000T0000Z-210910T0300Z/
Deerlodge/West Beaverhead-East Beaverhead-
838 PM MDT Thu Sep 9 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING...

* Affected area: Fire Zone 110 (Deerlodge/West Beaverhead). Fire 
  Zone 111 (East Beaverhead). 

* Impacts: Critical fire weather conditions are expected to 
  diminish.

&&

$$

Nearby

Red Flag Warnings in Montana, 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.