Alert archive / Montana / Red Flag Warnings in 2021

Red Flag Warning 8, NWS Great Falls, MT

July 18, 202111 counties in Montana

NWS Great Falls, MT issued this red flag warning at Jul 18, 2021, 1:58 PM MDT for 11 counties in Montana. It took effect at Jul 19, 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 18, 2021, 1:58 PM MDT (19:58 UTC)
In effect from
Jul 19, 2021, 12:00 PM MDT
Expired
Jul 19, 2021, 9:00 PM MDT
In force
9 hr
Issued by
NWS Great Falls, MT

Counties Broadwater County, MT, Cascade County, MT, Fergus County, MT, Gallatin County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Meagher County, MT, Pondera County, MT, Powell County, MT, Teton County, MT

The radar

The Great Falls radar (KTFX), 59 km from the middle of the area, began a volume at 20:00 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, 8.0 hours before the alert went out and 88 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 2021-07-18Temperature 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 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
3122 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

990 
WWUS85 KTFX 181958
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
158 PM MDT Sun Jul 18 2021

MTZ116-118-191100-
/O.NEW.KTFX.FW.W.0008.210719T1800Z-210720T0300Z/
Lincoln Ranger District of the Helena National Forest-
Helena and Townsend Ranger Districts of the Helena National Forest-
158 PM MDT Sun Jul 18 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT MONDAY FOR DRY
THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW WINDS FOR FIRE
WEATHER ZONES 116 AND 118...

The National Weather Service in Great Falls has issued a Red Flag
Warning for dry thunderstorms with gusty and erratic outflow
winds, which is in effect from noon to 9 PM MDT Monday.

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

* IMPACTS...Gusty and erratic outflows developing from high-based
  scattered thunderstorms and frequent lightning in areas.

* THUNDERSTORMS...A mix of wet and dry thunderstorms over the Red
  Flag Warning area.

* OUTFLOW WINDS...Erratic outflow gusts over 40 mph possible.

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
4 follow-up statements
045 
WWUS85 KTFX 190823
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
223 AM MDT Mon Jul 19 2021

MTZ114-117-192200-
/O.EXA.KTFX.FW.W.0008.210719T1800Z-210720T0300Z/
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-
Central and Eastern Lewis and Clark National Forest Areas-
223 AM MDT Mon Jul 19 2021

...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS
EVENING FOR DRY THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW WINDS
FOR FIRE WEATHER ZONES 114 AND 117...

The National Weather Service in Great Falls has issued a Red Flag
Warning for dry thunderstorms with gusty and erratic outflow
winds, which is in effect from noon today to 9 PM MDT this
evening.

* AFFECTED AREA...Lewis and Clark National Forest Rocky Mountain 
  District-Rocky Mountain Front and Central and Eastern Lewis and 
  Clark National Forest Areas.

* LIGHTNING...

* IMPACTS...Gusty and erratic outflows developing from high-based
  scattered thunderstorms and frequent lightning in some areas. 

* THUNDERSTORMS...A mix of wet and dry thunderstorms over the Red
  Flag Warning area. Wetting rain will become more likely with
  storms Monday evening but the increase in lightning activity 
  following recent heat and dry fuels could lead to new fire 
  starts. 

* OUTFLOW WINDS...Erratic outflow gusts over 40 mph possible.

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.

&&

$$

MTZ116-118-192200-
/O.CON.KTFX.FW.W.0008.210719T1800Z-210720T0300Z/
Lincoln Ranger District of the Helena National Forest-
Helena and Townsend Ranger Districts of the Helena National Forest-
223 AM MDT Mon Jul 19 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT
THIS EVENING FOR DRY THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW
WINDS FOR FIRE WEATHER ZONES 116 AND 118...

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

* IMPACTS...Gusty and erratic outflows developing from high-based 
  scattered thunderstorms and frequent lightning in areas.

* THUNDERSTORMS...A mix of wet and dry thunderstorms over the Red 
  Flag Warning area.

* OUTFLOW WINDS...Erratic outflow gusts over 40 mph possible.

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
612 
WWUS85 KTFX 192011
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
211 PM MDT Mon Jul 19 2021

MTZ114-116>118-200300-
/O.CON.KTFX.FW.W.0008.000000T0000Z-210720T0300Z/
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-
Lincoln Ranger District of the Helena National Forest-
Central and Eastern Lewis and Clark National Forest Areas-
Helena and Townsend Ranger Districts of the Helena National Forest-
211 PM MDT Mon Jul 19 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR DRY THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW WINDS FOR
FIRE WEATHER ZONES 114 AND 117...

* AFFECTED AREA...Lewis and Clark National Forest Rocky Mountain 
  District-Rocky Mountain Front, Lincoln Ranger District of the 
  Helena National Forest, Central and Eastern Lewis and Clark 
  National Forest Areas and Helena and Townsend Ranger Districts 
  of the Helena National Forest.

* IMPACTS...Gusty and erratic outflows developing from high-based 
  scattered thunderstorms and frequent lightning in some areas.

* THUNDERSTORMS...A mix of wet and dry thunderstorms over the Red 
  Flag Warning area. Wetting rain will become more likely with 
  storms Monday evening but the increase in lightning activity 
  following recent heat and dry fuels could lead to new fire 
  starts.

* OUTFLOW WINDS...Erratic outflow gusts over 40 mph possible.

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
195 
WWUS85 KTFX 192145 CCA
RFWTFX

URGENT - FIRE WEATHER MESSAGE...CORRECTED
National Weather Service Great Falls MT
345 PM MDT Mon Jul 19 2021

MTZ114-116>118-200300-
/O.COR.KTFX.FW.W.0008.000000T0000Z-210720T0300Z/
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-
Lincoln Ranger District of the Helena National Forest-
Central and Eastern Lewis and Clark National Forest Areas-
Helena and Townsend Ranger Districts of the Helena National Forest-
345 PM MDT Mon Jul 19 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING
FOR DRY THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW WINDS FOR
FIRE WEATHER ZONES 114, 116, 117, AND 118...

* AFFECTED AREA...Lewis and Clark National Forest Rocky Mountain 
  District-Rocky Mountain Front, Lincoln Ranger District of the 
  Helena National Forest, Central and Eastern Lewis and Clark 
  National Forest Areas and Helena and Townsend Ranger Districts 
  of the Helena National Forest.

* IMPACTS...Gusty and erratic outflows developing from high-based 
  scattered thunderstorms and frequent lightning in some areas.

* THUNDERSTORMS...A mix of wet and dry thunderstorms over the Red 
  Flag Warning area. Wetting rain will become more likely with 
  storms Monday evening but the increase in lightning activity 
  following recent heat and dry fuels could lead to new fire 
  starts.

* OUTFLOW WINDS...Erratic outflow gusts over 40 mph possible.

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
068 
WWUS85 KTFX 200242
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
842 PM MDT Mon Jul 19 2021

MTZ114-116>118-200345-
/O.EXP.KTFX.FW.W.0008.000000T0000Z-210720T0300Z/
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-
Lincoln Ranger District of the Helena National Forest-
Central and Eastern Lewis and Clark National Forest Areas-
Helena and Townsend Ranger Districts of the Helena National Forest-
842 PM MDT Mon Jul 19 2021

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR DRY
THUNDERSTORMS WITH GUSTY AND ERRATIC OUTFLOW WINDS FOR FIRE 
WEATHER ZONES 114, 116, 117, AND 118...

Thunderstorm activity has ended for the evening; therefore, the Red
Flag Warning will be allowed to expire. 

$$

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