Alert archive / Montana / Special Weather Statements in 2020

Special Weather Statement, NWS Great Falls, MT

August 3, 2020

NWS Great Falls, MT issued this special weather statement at Aug 3, 2020, 5:21 PM MDT. It was in force for 39 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: Aug 3, 2020, 5:21 PM MDT (23:21 UTC)
Expired: Aug 3, 2020, 6:00 PM MDT
In force: 39 min
Issued by: NWS Great Falls, MT

The radar

The Pocatello radar (KSFX), 185 km from the middle of the area, began a volume at 23:22 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, 11.4 hours before the alert went out and 326 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: 597 J/kg
Mixed-layer CIN: -290 J/kg
Mixed-layer LCL: 2351 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

382 
WWUS85 KTFX 032321
SPSTFX

Special Weather Statement
National Weather Service Great Falls MT
521 PM MDT Mon Aug 3 2020

MTZ008-040000-
Beaverhead-
521 PM MDT Mon Aug 3 2020

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT SOUTHEASTERN 
BEAVERHEAD COUNTY...

At 519 PM MDT, strong thunderstorms were over Southern Beaverhead 
County, moving northeast at 25 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Lima, Monida, Dell, Lakeview, Snowline and Monida Pass. 

This includes Interstate 15 between mile markers 1  and 27 .
 
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.

Persons in campgrounds should consider seeking sturdy shelter until
these storms pass.

LAT...LON 4449 11276 4497 11274 4510 11246 4509 11234
      4500 11233 4499 11219 4483 11216 4483 11207
      4478 11206 4478 11179 4471 11177 4471 11150
      4459 11153 4455 11148 4456 11171 4451 11182
      4456 11187 4452 11211 4457 11229 4445 11239
TIME...MOT...LOC 2319Z 205DEG 27KT 4475 11262 

$$

RCG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 8:07 AM MDT	Special Weather Statement	TFX	Teton	38 min
Aug 3, 8:30 AM MDT	Special Weather Statement	TFX	Teton	30 min
Aug 3, 8:50 AM MDT	Special Weather Statement	TFX	Cascade	40 min
Aug 3, 9:26 AM MDT	Special Weather Statement	TFX	Chouteau	64 min
Aug 3, 10:07 AM MDT	Special Weather Statement	TFX	Chouteau	53 min
Aug 3, 10:52 AM MDT	Special Weather Statement	TFX	Chouteau	53 min
Aug 3, 10:59 AM MDT	Special Weather Statement	TFX	Chouteau	46 min
Aug 3, 11:48 AM MDT	Special Weather Statement	TFX	Chouteau	57 min
Aug 3, 12:19 PM MDT	Severe Thunderstorm Warning	TFX	Judith Basin	41 min
Aug 3, 12:32 PM MDT	Special Weather Statement	TFX	Blaine	43 min
Aug 3, 1:02 PM MDT	Special Weather Statement	TFX	Fergus	43 min
Aug 3, 1:40 PM MDT	Special Weather Statement	TFX	Fergus	65 min
Aug 3, 2:16 PM MDT	Special Weather Statement	TFX	Blaine	44 min
Aug 3, 2:27 PM MDT	Special Weather Statement	TFX	Fergus	48 min
Aug 3, 2:36 PM MDT	Special Weather Statement	TFX		24 min
Aug 3, 3:23 PM MDT	Special Weather Statement	TFX		22 min
Aug 3, 3:40 PM MDT	Special Weather Statement	TFX	Madison	35 min
Aug 3, 4:27 PM MDT	Special Weather Statement	TFX	Madison	48 min
Aug 3, 4:41 PM MDT	Special Weather Statement	TFX	Chouteau	34 min
Aug 3, 4:51 PM MDT	Special Weather Statement	TFX	Judith Basin	24 min
Aug 3, 5:03 PM MDT	Special Weather Statement	TFX	Teton	27 min
Aug 3, 5:13 PM MDT	Special Weather Statement	TFX	Chouteau	32 min
Aug 3, 5:28 PM MDT	Special Weather Statement	TFX	Gallatin, Madison	47 min
Aug 3, 5:34 PM MDT	Special Weather Statement	TFX	Liberty	26 min
Aug 3, 5:36 PM MDT	Special Weather Statement	TFX	Fergus	24 min
Aug 3, 5:46 PM MDT	Special Weather Statement	TFX	Chouteau	29 min
Aug 3, 5:49 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin, Madison	26 min

Nearby

Special Weather Statements in Montana, 2020 Every special weather statement in 2020

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.