Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 28, NWS Great Falls, MT

July 6, 2021Blaine County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 6, 2021, 7:27 PM MDT for Blaine County, Montana. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 6, 2021, 7:27 PM MDT (01:27 UTC)
Expired
Jul 6, 2021, 8:30 PM MDT
In force
63 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

County Blaine County, MT

The radar

The Glasgow radar (KGGW), 144 km from the middle of the area, began a volume at 01:30 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.5 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, Glasgow Intl Airport, MT at 00:00Z on 2021-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 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, Glasgow Intl Airport, MT at 00:00Z on 2021-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
20 J/kg
Mixed-layer CIN
-155 J/kg
Mixed-layer LCL
1401 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

691 
WUUS55 KTFX 070127
SVRTFX
MTC005-070230-
/O.NEW.KTFX.SV.W.0028.210707T0127Z-210707T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
727 PM MDT Tue Jul 6 2021

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Northern Blaine County in north central Montana...

* Until 830 PM MDT.

* At 726 PM MDT, severe thunderstorms were located along a line
  extending from 12 miles north of Turner to 25 miles north of
  Harlem, moving southeast at 20 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* Locations impacted include...
  Harlem, Fort Belknap, Turner, Hogeland and Zurich. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4892 10824 4891 10826 4875 10826 4874 10832
      4858 10831 4856 10835 4844 10835 4844 10842
      4811 10844 4869 10929 4900 10896 4900 10823
TIME...MOT...LOC 0126Z 317DEG 20KT 4903 10838 4888 10891 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG
5 follow-up statements
575 
WWUS55 KTFX 070143
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
743 PM MDT Tue Jul 6 2021

MTC005-070230-
/O.CON.KTFX.SV.W.0028.000000T0000Z-210707T0230Z/
Blaine MT-
743 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR NORTHERN BLAINE COUNTY...

At 743 PM MDT, severe thunderstorms were located along a line
extending from 9 miles northeast of Turner to 19 miles north of
Harlem, moving southeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Harlem, Fort Belknap, Turner, Hogeland and Zurich. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4892 10824 4891 10826 4875 10826 4874 10832
      4858 10831 4856 10835 4844 10835 4844 10842
      4811 10844 4869 10929 4891 10880 4900 10850
      4900 10823
TIME...MOT...LOC 0143Z 317DEG 20KT 4896 10829 4882 10882 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG
711 
WWUS55 KTFX 070152
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
752 PM MDT Tue Jul 6 2021

MTC005-070230-
/O.CON.KTFX.SV.W.0028.000000T0000Z-210707T0230Z/
Blaine MT-
752 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR NORTHEASTERN BLAINE COUNTY...

At 751 PM MDT, severe thunderstorms were located along a line
extending from 9 miles northeast of Turner to 17 miles north of
Harlem, moving southeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Harlem, Fort Belknap, Turner, Hogeland and Zurich. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4892 10824 4891 10826 4875 10826 4874 10832
      4858 10831 4856 10835 4844 10835 4844 10842
      4811 10844 4853 10905 4874 10903 4888 10871
      4900 10841 4900 10823
TIME...MOT...LOC 0151Z 317DEG 20KT 4894 10825 4879 10878 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG
318 
WWUS55 KTFX 070202
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
802 PM MDT Tue Jul 6 2021

MTC005-070230-
/O.CON.KTFX.SV.W.0028.000000T0000Z-210707T0230Z/
Blaine MT-
802 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR NORTHEASTERN BLAINE COUNTY...

At 802 PM MDT, severe thunderstorms were located along a line
extending from 10 miles east of Turner to 14 miles north of Harlem,
moving southeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Harlem, Fort Belknap and Turner. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4892 10824 4891 10826 4875 10826 4874 10832
      4858 10831 4856 10835 4844 10835 4844 10842
      4811 10844 4844 10891 4858 10887 4869 10885
      4883 10850 4895 10824 4900 10823
TIME...MOT...LOC 0202Z 317DEG 20KT 4889 10819 4874 10871 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG
952 
WWUS55 KTFX 070210
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
810 PM MDT Tue Jul 6 2021

MTC005-070230-
/O.CON.KTFX.SV.W.0028.000000T0000Z-210707T0230Z/
Blaine MT-
810 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR EAST CENTRAL BLAINE COUNTY...

At 810 PM MDT, severe thunderstorms were located along a line
extending from 11 miles east of Turner to 13 miles north of Harlem,
moving southeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Harlem and Fort Belknap. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4861 10836 4859 10832 4858 10834 4858 10831
      4856 10835 4844 10835 4844 10842 4811 10844
      4844 10891 4858 10887 4869 10885 4871 10850
      4859 10834
TIME...MOT...LOC 0210Z 317DEG 20KT 4887 10817 4872 10869 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG
974 
WWUS55 KTFX 070222
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
822 PM MDT Tue Jul 6 2021

MTC005-070230-
/O.CON.KTFX.SV.W.0028.000000T0000Z-210707T0230Z/
Blaine MT-
822 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM MDT
FOR EAST CENTRAL BLAINE COUNTY...

At 822 PM MDT, severe thunderstorms were located along a line
extending from 12 miles west of Loring to 12 miles northeast of
Harlem, moving southeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Fort Belknap.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4857 10835 4856 10836 4854 10835 4844 10835
      4844 10842 4812 10844 4837 10880 4854 10877
      4858 10867 4865 10852 4858 10840
TIME...MOT...LOC 0222Z 317DEG 20KT 4884 10812 4869 10864 

HAIL...1.75IN
WIND...60MPH
 
$$

RCG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 6:14 PM MDTSevere Thunderstorm WarningTFXBlaine29 min
Jul 6, 6:16 PM MDTSpecial Weather StatementTFXToole29 min
Jul 6, 6:50 PM MDTSevere Thunderstorm WarningTFXBlaine40 min
Jul 6, 6:57 PM MDTSpecial Weather StatementTFXToole33 min
Jul 6, 7:30 PM MDTSpecial Weather StatementTFXLiberty30 min
Jul 6, 8:20 PM MDTTornado WarningTFXBlaine25 min
Jul 6, 8:45 PM MDTSevere Thunderstorm WarningTFXBlaine19 min
Jul 7, 1:51 PM MDTSpecial Weather StatementTFXBeaverhead39 min
Jul 7, 2:03 PM MDTSpecial Weather StatementTFXJudith Basin27 min
Jul 7, 2:18 PM MDTSpecial Weather StatementTFXFergus27 min
Jul 7, 2:43 PM MDTSpecial Weather StatementTFXFergus32 min
Jul 7, 2:46 PM MDTSevere Thunderstorm WarningTFXFergus29 min
Jul 7, 2:55 PM MDTSpecial Weather StatementTFXMadison50 min
Jul 7, 3:06 PM MDTSpecial Weather StatementTFXJefferson54 min
Jul 7, 3:13 PM MDTSevere Thunderstorm WarningTFXFergus47 min
Jul 7, 3:21 PM MDTSpecial Weather StatementTFXFergus24 min
Jul 7, 3:26 PM MDTSevere Thunderstorm WarningTFXJefferson, Lewis and Clark34 min
Jul 7, 3:36 PM MDTSpecial Weather StatementTFXFergus24 min
Jul 7, 3:40 PM MDTSpecial Weather StatementTFXLewis and Clark35 min
Jul 7, 3:46 PM MDTSpecial Weather StatementTFXBroadwater, Jefferson44 min
Jul 7, 3:55 PM MDTSpecial Weather StatementTFXGallatin50 min
Jul 7, 3:59 PM MDTSpecial Weather StatementTFXFergus46 min
Jul 7, 4:02 PM MDTSpecial Weather StatementTFXBroadwater, Jefferson43 min
Jul 7, 4:30 PM MDTSevere Thunderstorm WarningTFXGallatin30 min
Jul 7, 4:36 PM MDTSevere Thunderstorm WarningTFXGallatin15 min
Jul 7, 4:48 PM MDTSpecial Weather StatementTFXSilver Bow27 min
Jul 7, 4:56 PM MDTSpecial Weather StatementTFXMeagher34 min
Jul 7, 5:12 PM MDTSpecial Weather StatementTFXJudith Basin48 min
Jul 7, 5:13 PM MDTSpecial Weather StatementTFXBlaine62 min
Jul 7, 5:38 PM MDTSevere Thunderstorm WarningTFXBlaine37 min
Jul 7, 5:56 PM MDTSpecial Weather StatementTFXBlaine34 min

Nearby

Severe Thunderstorm Warnings in Montana, 2021Every severe thunderstorm 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.