Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Great Falls, MT

July 9, 2021

NWS Great Falls, MT issued this special weather statement at Jul 9, 2021, 5:43 PM MDT. It was in force for 32 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 9, 2021, 5:43 PM MDT (23:43 UTC)
Expired: Jul 9, 2021, 6:15 PM MDT
In force: 32 min
Issued by: NWS Great Falls, MT

The radar

The Glasgow radar (KGGW), 166 km from the middle of the area, began a volume at 23:46 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.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.7 hours before the alert went out and 142 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 34 J/kg
Mixed-layer CIN: -410 J/kg
Mixed-layer LCL: 1971 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: -47 m²/s²
0-3 km storm-relative helicity: -52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Great Falls, MT wrote its last area forecast discussion before this special weather statement went out at Jul 9, 5:41 PM MDT, 2 minutes earlier.

Area forecast discussion, Jul 9, 5:41 PM MDT, 2 minutes before

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In the hours before

Special weather statement, Jul 9, 3:48 PM MDT, 1 hour 55 minutes before

Special Weather Statement
National Weather Service Great Falls MT
348 PM MDT Fri Jul 9 2021

MTZ044-046-092215-
Eastern Pondera MT-Toole MT-
348 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN PONDERA...AND SOUTH
CENTRAL TOOLE COUNTIES UNTIL 415 PM MDT...

At 346 PM MDT, Doppler radar was tracking strong thunderstorms 11
miles northeast of Conrad. This storm was nearly stationary.

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Ledger.

This includes Interstate 15 between mile markers 345 and 351.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If you are on or near any area lakes, be prepared to get out of the
water and move indoors or inside a vehicle. Remember, lightning can
strike out to 10 miles from the parent thunderstorm. If you can hear
thunder, you are close enough to be struck by lightning. Move to
safe shelter now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4823 11128 4822 11128 4821 11141 4811 11141
      4798 11175 4834 11200 4844 11169
TIME...MOT...LOC 2146Z 321DEG 4KT 4826 11174

RCG

Special weather statement, Jul 9, 3:52 PM MDT, 1 hour 51 minutes before

Special Weather Statement
National Weather Service Great Falls MT
352 PM MDT Fri Jul 9 2021

MTZ011-013-047-092230-
Chouteau MT-Hill MT-Blaine MT-
352 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL BLAINE...HILL AND
NORTHEASTERN CHOUTEAU COUNTIES UNTIL 430 PM MDT...

At 350 PM MDT, Doppler radar was tracking strong thunderstorms over
Blaine, Chouteau, and Hill Counties. Movement was south at 10 mph.

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Havre, Chinook, Big Sandy, Harlem, Parker School, Beaver Creek,
Azure, Inverness, Agency, St. Pierre, Gildford, Sangrey, Boneau, Fort
Belknap, Box Elder, Hingham, Rudyard, Rocky Boy, Cleveland and
Zurich.

This includes the following highways...
 Highway 2 between mile markers 336 and 443.
 Highway 87 between mile markers 60 and 111.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If you are on or near any area lakes, be prepared to get out of the
water and move indoors or inside a vehicle. Remember, lightning can
strike out to 10 miles from the parent thunderstorm. If you can hear
thunder, you are close enough to be struck by lightning. Move to
safe shelter now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4851 10841 4832 10852 4806 10872 4780 10943
      4804 11048 4814 11062 4825 11070 4890 11067
      4874 10979 4866 10896 4876 10860
TIME...MOT...LOC 2150Z 357DEG 10KT 4871 10859 4857 10895 4845 10972
4849 11051

RCG

Special weather statement, Jul 9, 4:14 PM MDT, 1 hour 29 minutes before

Special Weather Statement
National Weather Service Great Falls MT
414 PM MDT Fri Jul 9 2021

MTZ044>046-092245-
Liberty MT-Eastern Pondera MT-Toole MT-
414 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PONDERA...
SOUTHWESTERN LIBERTY...SOUTHEASTERN TOOLE COUNTIES UNTIL 445 PM
MDT...

At 412 PM MDT, Doppler radar was tracking strong thunderstorms 11
miles east of Conrad. The storms were nearly stationary.

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Ledger.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If you are on or near any area lakes, be prepared to get out of the
water and move indoors or inside a vehicle. Remember, lightning can
strike out to 10 miles from the parent thunderstorm. If you can hear
thunder, you are close enough to be struck by lightning. Move to
safe shelter now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4820 11114 4813 11135 4813 11140 4811 11141
      4801 11168 4828 11191 4838 11161
TIME...MOT...LOC 2212Z 321DEG 4KT 4824 11171

RCG

Special weather statement, Jul 9, 4:20 PM MDT, 1 hour 23 minutes before

Special Weather Statement
National Weather Service Great Falls MT
420 PM MDT Fri Jul 9 2021

MTZ011-013-047-092300-
Chouteau MT-Hill MT-Blaine MT-
420 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN FERGUS...CENTRAL
BLAINE...CENTRAL HILL AND NORTHEASTERN CHOUTEAU COUNTIES UNTIL 500 PM
MDT...

At 418 PM MDT, Doppler radar was tracking strong thunderstorms over
portions of Blaine, Chouteau, and Hill Counties. Movement was south
southeast at 10 mph

HAZARD...Winds up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Havre, Chinook, Big Sandy, Harlem, Parker School, Beaver Creek,
Azure, Agency, St. Pierre, Gildford, Sangrey, Boneau, Fort Belknap,
Box Elder, Hingham, Rudyard, Rocky Boy, Cleveland, Zurich and
Kenilworth.

This includes the following highways...
 Highway 2 between mile markers 338 and 445.
 Highway 87 between mile markers 57 and 111.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If you are on or near any area lakes, be prepared to get out of the
water and move indoors or inside a vehicle. Remember, lightning can
strike out to 10 miles from the parent thunderstorm. If you can hear
thunder, you are close enough to be struck by lightning. Move to
safe shelter now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4844 10842 4826 10841 4805 10867 4774 10938
      4800 11051 4825 11070 4885 11061 4865 10980
      4859 10893 4852 10834 4844 10835
TIME...MOT...LOC 2218Z 350DEG 15KT 4856 10853 4841 10888 4829 10966
4833 11044

RCG

Special weather statement, Jul 9, 4:59 PM MDT, 44 minutes before

Special Weather Statement
National Weather Service Great Falls MT
459 PM MDT Fri Jul 9 2021

MTZ011-013-047-092345-
Chouteau MT-Hill MT-Blaine MT-
459 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN FERGUS...SOUTHWESTERN
BLAINE...SOUTHERN HILL AND NORTHEASTERN CHOUTEAU COUNTIES UNTIL 545
PM MDT...

At 457 PM MDT, Doppler radar was tracking strong thunderstorms
clustered around the Bear's Paw Mountains. Movement was southeast at
15 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Big Sandy, Azure, Parker School, Agency, St. Pierre, Sangrey, Boneau,
Box Elder, Rocky Boy, Laredo, Kenilworth, Lloyd, Judith Landing,
Iliad and Virgelle.

This includes Highway 87 between mile markers 58 and 101.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If you are on or near any area lakes, be prepared to get out of the
water and move indoors or inside a vehicle. Remember, lightning can
strike out to 10 miles from the parent thunderstorm. If you can hear
thunder, you are close enough to be struck by lightning. Move to
safe shelter now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4772 10894 4775 10892 4781 10898 4778 10913
      4780 10927 4772 10943 4774 10967 4770 10973
      4772 10982 4766 10984 4763 11017 4812 11055
      4824 11072 4854 11072 4837 10922 4781 10889
      4774 10890 4773 10890
TIME...MOT...LOC 2257Z 329DEG 21KT 4803 10906 4807 10977 4816 11026

RCG

Special weather statement, Jul 9, 5:43 PM MDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 8:19 AM MDT	Special Weather Statement	TFX	Teton	41 min
Jul 9, 8:41 AM MDT	Special Weather Statement	TFX	Teton	49 min
Jul 9, 8:53 AM MDT	Special Weather Statement	TFX	Teton	52 min
Jul 9, 12:22 PM MDT	Special Weather Statement	TFX	Lewis and Clark	23 min
Jul 9, 12:34 PM MDT	Special Weather Statement	TFX	Lewis and Clark	41 min
Jul 9, 12:52 PM MDT	Special Weather Statement	TFX	Lewis and Clark	23 min
Jul 9, 1:03 PM MDT	Special Weather Statement	TFX	Meagher	27 min
Jul 9, 1:12 PM MDT	Special Weather Statement	TFX	Lewis and Clark	33 min
Jul 9, 1:31 PM MDT	Special Weather Statement	TFX	Blaine	29 min
Jul 9, 1:42 PM MDT	Special Weather Statement	TFX	Broadwater	33 min
Jul 9, 1:55 PM MDT	Special Weather Statement	TFX	Blaine	35 min
Jul 9, 1:59 PM MDT	Special Weather Statement	TFX	Cascade	31 min
Jul 9, 2:05 PM MDT	Special Weather Statement	TFX	Glacier	25 min
Jul 9, 2:16 PM MDT	Special Weather Statement	TFX	Pondera	29 min
Jul 9, 2:21 PM MDT	Special Weather Statement	TFX	Broadwater	24 min
Jul 9, 2:28 PM MDT	Special Weather Statement	TFX	Blaine	32 min
Jul 9, 2:44 PM MDT	Special Weather Statement	TFX	Pondera	31 min
Jul 9, 2:46 PM MDT	Special Weather Statement	TFX	Blaine	29 min
Jul 9, 2:51 PM MDT	Special Weather Statement	TFX	Glacier	24 min
Jul 9, 3:11 PM MDT	Special Weather Statement	TFX	Blaine, Hill	34 min
Jul 9, 3:17 PM MDT	Special Weather Statement	TFX	Pondera	28 min
Jul 9, 3:18 PM MDT	Special Weather Statement	TFX	Glacier	27 min
Jul 9, 3:40 PM MDT	Special Weather Statement	TFX	Cascade	35 min
Jul 9, 3:48 PM MDT	Special Weather Statement	TFX	Pondera	27 min
Jul 9, 3:52 PM MDT	Special Weather Statement	TFX	Blaine, Hill	38 min
Jul 9, 4:14 PM MDT	Special Weather Statement	TFX	Pondera	31 min
Jul 9, 4:20 PM MDT	Special Weather Statement	TFX	Blaine, Hill	40 min
Jul 9, 4:59 PM MDT	Special Weather Statement	TFX	Chouteau	46 min

Nearby

Special Weather Statements in Montana, 2021 Every special weather statement 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.