Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 12, NWS Great Falls, MT

August 7, 20215 counties in Montana

NWS Great Falls, MT issued this red flag warning at Aug 7, 2021, 10:48 AM MDT for 5 counties in Montana. It took effect at Aug 8, 2021, 12:00 PM MDT. It was in force for 7 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 7, 2021, 10:48 AM MDT (16:48 UTC)
In effect from
Aug 8, 2021, 12:00 PM MDT
Expired
Aug 8, 2021, 7:26 PM MDT
In force
7 hr
Issued by
NWS Great Falls, MT

Counties Broadwater County, MT, Gallatin County, MT, Jefferson County, MT, Lewis and Clark County, MT, Meagher County, MT

The radar

The Great Falls radar (KTFX), 125 km from the middle of the area, began a volume at 16:46 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 8, 2:35 PM MDTTSTM WND DMG5 Ne Townsend, MTREPORT FROM BROADWATER SHERIFF OF MINOR TREE DAMAGE IN BROADWATER COUNTY.
Aug 8, 2:40 PM MDTTSTM WND GST 509 Ene Winston, MTESTIMATED WIND GUSTS NEAR 50 MPH.
Aug 8, 3:14 PM MDTNON-TSTM WND GST 671 Wnw Logan, MTMEASURED BY KMTTHREE22. MAX SUSTAINED WIND OF 58MPH WITH PEAK GUST OF 67 MPH. TEMP DROPPED FROM 92 TO 65 IN ABOUT 15 MIN.
Aug 8, 3:29 PM MDTNON-TSTM WND GST 623 N Manhattan, MTREPORTED BY AMBIENT WEATHER NETWORK.
Aug 8, 3:42 PM MDTNON-TSTM WND GST 55Bozeman Yellowstone Int, MTKBZN ASOS.
Aug 8, 3:42 PM MDTNON-TSTM WND GST 606 N Belgrade, MTNON TSTORM WIND GUST OF 60.4 MPH MEASURED BY AMBIENT WEATHER STATION.

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 12:00Z, 4.8 hours before the alert went out and 145 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 2021-08-07Temperature 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 12:00Z on 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1763 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

183 
WWUS85 KTFX 071648
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
1048 AM MDT Sat Aug 7 2021

MTZ118-081200-
/O.UPG.KTFX.FW.A.0009.210808T1800Z-210809T0300Z/
/O.NEW.KTFX.FW.W.0012.210808T1800Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
1048 AM MDT Sat Aug 7 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT SUNDAY FOR LOW
RELATIVE HUMIDITY, AS WELL AS, WIND SHIFT AND STRONG WINDS WITH A 
COLD FRONT FOR FIRE WEATHER ZONE 118...

The National Weather Service in Great Falls has issued a Red Flag
Warning which is in effect from noon to 9 PM MDT Sunday, for low 
relative humidity, as well as, wind shift and strong winds with a 
cold front. The Fire Weather Watch is no longer in effect.

* AFFECTED AREA...Helena and Townsend Ranger Districts of the 
  Helena National Forest.

* THUNDERSTORMS...Some thunderstorm activity is possible along the
  cold front, as well. 

* WINDS...Northwest 15 to 20 mph with gusts up to 40 mph.


* RELATIVE HUMIDITY...As low as 19 percent.

* HUMIDITY...Humidity as low as 15 percent before the cold front 
  arrives.
 
* IMPACTS...Lightning in and near thunderstorms may cause new fire
  starts. In addition, gusty outflow winds may cause existing fires
  to exhibit erratic behavior.

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.

&&

Fogleman

$$

http://www.weather.gov/greatfalls
5 follow-up statements
483 
WWUS85 KTFX 071655
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
1055 AM MDT Sat Aug 7 2021

MTZ118-081200-
/O.CON.KTFX.FW.W.0012.210808T1800Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
1055 AM MDT Sat Aug 7 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 9 PM MDT SUNDAY
FOR LOW RELATIVE HUMIDITY, AS WELL AS, WIND SHIFT AND STRONG WINDS
WITH A COLD FRONT FOR FIRE WEATHER ZONE 118...

* AFFECTED AREA...Helena and Townsend Ranger Districts of the 
  Helena National Forest.

* THUNDERSTORMS...Some thunderstorm activity is possible along 
  the cold front, as well.

* WINDS...Northwest 15 to 20 mph with gusts up to 40 mph.

* RELATIVE HUMIDITY...As low as 19 percent.

* IMPACTS...Lightning in and near thunderstorms may cause new 
  fire starts. In addition, gusty outflow winds may cause 
  existing fires to exhibit erratic behavior.

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.

&&

Fogleman

$$

http://www.weather.gov/greatfalls
836 
WWUS85 KTFX 080849
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
249 AM MDT Sun Aug 8 2021

MTZ118-090300-
/O.CON.KTFX.FW.W.0012.210808T1800Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
249 AM MDT Sun Aug 8 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT
THIS EVENING FOR LOW RELATIVE HUMIDITY, STRONG WINDS, AND A FRONTAL
PASSAGE FOR FIRE WEATHER ZONE 118...

* AFFECTED AREA...Helena and Townsend Ranger Districts of the 
  Helena National Forest.

* THUNDERSTORMS...Some thunderstorm activity is possible along the
  cold front.

* WINDS...Southwest 15 to 25 mph, switching to north-northwest 15 
  to 25 mph with gusts up to 40 mph in the afternoon.

* RELATIVE HUMIDITY...As low as 18 percent.

* IMPACTS...Lightning in and near thunderstorms may cause new 
  fire starts. In addition, gusty outflow winds may cause 
  existing fires to exhibit erratic behavior.

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
089 
WWUS85 KTFX 082005
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
205 PM MDT Sun Aug 8 2021

MTZ118-090300-
/O.CON.KTFX.FW.W.0012.000000T0000Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
205 PM MDT Sun Aug 8 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR LOW RELATIVE HUMIDITY, STRONG WINDS, AND A FRONTAL PASSAGE FOR
FIRE WEATHER ZONE 118...

* AFFECTED AREA...Helena and Townsend Ranger Districts of the 
  Helena National Forest.

* THUNDERSTORMS...Some thunderstorm activity is possible along 
  the cold front.

* WINDS...Northwest 15 to 25 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 15 percent.

* IMPACTS...Lightning in and near thunderstorms may cause new 
  fire starts. In addition, gusty outflow winds may cause 
  existing fires to exhibit erratic behavior.

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
780 
WWUS85 KTFX 082138
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
338 PM MDT Sun Aug 8 2021

MTZ118-090300-
/O.CON.KTFX.FW.W.0012.000000T0000Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
338 PM MDT Sun Aug 8 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR LOW RELATIVE HUMIDITY, STRONG WINDS, AND A FRONTAL PASSAGE FOR
FIRE WEATHER ZONE 118...

* AFFECTED AREA...Helena and Townsend Ranger Districts of the 
  Helena National Forest.

* THUNDERSTORMS...Some thunderstorm activity is possible along 
  the cold front.

* WINDS...Northwest 15 to 25 mph with gusts up to 50 mph.

* RELATIVE HUMIDITY...As low as 15 percent.

* IMPACTS...Lightning in and near thunderstorms may cause new 
  fire starts. In addition, gusty outflow winds may cause 
  existing fires to exhibit erratic behavior.

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
147 
WWUS85 KTFX 090126
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
726 PM MDT Sun Aug 8 2021

MTZ118-090230-
/O.CAN.KTFX.FW.W.0012.000000T0000Z-210809T0300Z/
Helena and Townsend Ranger Districts of the Helena National Forest-
726 PM MDT Sun Aug 8 2021

...RED FLAG WARNING IS CANCELLED FOR LOW RELATIVE HUMIDITY, STRONG
WINDS, AND A FRONTAL PASSAGE FOR FIRE WEATHER ZONE 118...

The National Weather Service in Great Falls has cancelled the Red
Flag Warning.

Wetting rains have fallen across most of Fire Weather Zone 118 this
evening, and winds have begun to die down with rising humidity,
reducing the fire danger.

$$

http://www.weather.gov/greatfalls

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.