Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 10, NWS Great Falls, MT

July 31, 20219 counties in Montana

NWS Great Falls, MT issued this red flag warning at Jul 31, 2021, 1:36 PM MDT for 9 counties in Montana. It took effect at Aug 1, 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 31, 2021, 1:36 PM MDT (19:36 UTC)
In effect from
Aug 1, 2021, 12:00 PM MDT
Expired
Aug 1, 2021, 9:00 PM MDT
In force
9 hr
Issued by
NWS Great Falls, MT

Counties Blaine County, MT, Chouteau County, MT, Fergus County, MT, Glacier County, MT, Hill County, MT, Liberty County, MT, Phillips County, MT, Pondera County, MT, Toole County, MT

The radar

The Great Falls radar (KTFX), 113 km from the middle of the area, began a volume at 19:36 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, 7.6 hours before the alert went out and 93 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 2021-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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 2021-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
21 J/kg
Mixed-layer CIN
-211 J/kg
Mixed-layer LCL
2552 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

282 
WWUS85 KTFX 311936
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
136 PM MDT Sat Jul 31 2021

MTZ112-113-115-011100-
/O.UPG.KTFX.FW.A.0008.210801T1800Z-210802T0300Z/
/O.NEW.KTFX.FW.W.0010.210801T1800Z-210802T0300Z/
Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-
Hill and Blaine Counties-Chouteau and Fergus Counties-
136 PM MDT Sat Jul 31 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT SUNDAY FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 112, 
113, AND 115...

The National Weather Service in Great Falls has issued a Red Flag
Warning for gusty winds and low relative humidity, which is in 
effect from noon to 9 PM MDT Sunday. The Fire Weather Watch is no 
longer in effect.

* AFFECTED AREA...Eastern Glacier/Toole/Central/Eastern
  Pondera/Liberty, Hill and Blaine Counties and Chouteau and Fergus
  Counties.

* WINDS...Southeast 15 to 20 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Any fires, new or existing, may grow and spread 
  rapidly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now, or will shortly.  A combination of 
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

Please advise the appropriate officials or fire crews in these
areas of this Red Flag Warning.

&&

$$

http://www.weather.gov/greatfalls
2 follow-up statements
435 
WWUS85 KTFX 010743
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
143 AM MDT Sun Aug 1 2021

MTZ112-113-115-020300-
/O.CON.KTFX.FW.W.0010.210801T1800Z-210802T0300Z/
Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-
Hill and Blaine Counties-Chouteau and Fergus Counties-
143 AM MDT Sun Aug 1 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT
THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONES 112, 113, AND 115...

* AFFECTED AREA...Eastern Glacier/Toole/Central/Eastern 
  Pondera/Liberty, Hill and Blaine Counties and Chouteau and 
  Fergus Counties.

* WINDS...Southeast 15 to 20 mph, with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 13 percent.

* IMPACTS...Any fires, new or existing, may grow and spread 
  rapidly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now, or will shortly.  A combination of strong
winds, low relative humidity, and warm temperatures can contribute
to extreme fire behavior.

Please advise the appropriate officials or fire crews in these
areas of this Red Flag Warning.

&&

Moldan

$$

http://www.weather.gov/greatfalls
418 
WWUS85 KTFX 020236
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
836 PM MDT Sun Aug 1 2021

MTZ112-113-115-020345-
/O.EXP.KTFX.FW.W.0010.000000T0000Z-210802T0300Z/
Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-
Hill and Blaine Counties-Chouteau and Fergus Counties-
836 PM MDT Sun Aug 1 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR
GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 112,
113, AND 115...

Breezy easterly winds and low relative humidity are expected to
continue for the next couple hours; however, the trend is for 
winds to decrease and for relative humidity to increase. For these
reasons, the Red Flag Warning is allowed to expire. 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 9:49 PM MDTSpecial Weather StatementTFXGlacier41 min
Jul 31, 3:12 AM MDTFire Weather WatchTFXBlaine, Chouteau, Fergus, Glacier, Hill, Liberty and 3 more10 hr
Jul 31, 10:42 AM MDTFlash Flood WatchTFX37 hr
Jul 31, 1:32 PM MDTSpecial Weather StatementTFXJudith Basin28 min
Jul 31, 2:32 PM MDTSpecial Weather StatementTFXJudith Basin28 min

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.