Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 19, NWS Missoula, MT

September 14, 20214 counties in Montana

NWS Missoula, MT issued this red flag warning at Sep 14, 2021, 12:39 PM MDT for 4 counties in Montana. It took effect at Sep 15, 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
Sep 14, 2021, 12:39 PM MDT (18:39 UTC)
In effect from
Sep 15, 2021, 12:00 PM MDT
Expired
Sep 15, 2021, 9:00 PM MDT
In force
9 hr
Issued by
NWS Missoula, MT

Counties Beaverhead County, MT, Jefferson County, MT, Madison County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 200 km from the middle of the area, began a volume at 18:39 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

Great_falls, MT (KTFX), launched 12:00Z, 6.7 hours before the alert went out and 246 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 12:00Z on 2021-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Great_falls, MT at 12:00Z on 2021-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
1610 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

929 
WWUS85 KMSO 141839
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
1239 PM MDT Tue Sep 14 2021

MTZ111-151845-
/O.NEW.KMSO.FW.W.0019.210915T1800Z-210916T0300Z/
East Beaverhead-
1239 PM MDT Tue Sep 14 2021

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

* Affected area: Fire Zone 111 (East Beaverhead). 

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

* Winds: West 17 to 27 mph with gusts 35 to 45 mph.

* Minimum humidities: 15 to 20 percent.

&&

$$
1 follow-up statement
769 
WWUS85 KMSO 160246
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
846 PM MDT Wed Sep 15 2021

MTZ111-160400-
/O.EXP.KMSO.FW.W.0019.000000T0000Z-210916T0300Z/
East Beaverhead-
846 PM MDT Wed Sep 15 2021

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

Winds are diminishing and relative humidity is rising. The warning
will expire at 9 PM. 

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 2:36 PM MDTFreeze WatchMSOFlathead, Lincoln, Sanders23 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.