Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Great Falls, MT

July 9, 2021Broadwater County, Montana

NWS Great Falls, MT issued this special weather statement at Jul 9, 2021, 2:21 PM MDT for Broadwater County, Montana. It was in force for 24 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, 2:21 PM MDT (20:21 UTC)
Expired
Jul 9, 2021, 2:45 PM MDT
In force
24 min
Issued by
NWS Great Falls, MT

County Broadwater County, MT

The radar

The Great Falls radar (KTFX), 149 km from the middle of the area, began a volume at 20:20 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, 8.4 hours before the alert went out and 164 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 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -47 square meters per square second.19395878Sfc1 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
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.

058 
WWUS85 KTFX 092021
SPSTFX

Special Weather Statement
National Weather Service Great Falls MT
221 PM MDT Fri Jul 9 2021
 
MTZ052>054-092045-
Broadwater MT-Jefferson MT-Meagher MT-
221 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL 
BROADWATER...SOUTHWESTERN MEAGHER...EAST CENTRAL JEFFERSON COUNTIES 
UNTIL 245 PM MDT...

At 220 PM MDT, Doppler radar was tracking a strong thunderstorm 14
miles east of Boulder, moving southeast at 25 mph.

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

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Townsend, Toston, Radersburg and Elkhorn State Park. 

This includes the following highways... Interstate 90 between mile 
markers 269 and 276.
Highway 287 between mile markers 89 and 90, and near mile marker 93.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 4639 11185 4640 11100 4619 11122 4618 11134
      4613 11134 4611 11140 4602 11143 4600 11141
      4599 11146 4596 11147 4590 11160 4584 11166
      4621 11202
TIME...MOT...LOC 2020Z 307DEG 23KT 4623 11183 

$$

RCG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 8:19 AM MDTSpecial Weather StatementTFXTeton41 min
Jul 9, 8:41 AM MDTSpecial Weather StatementTFXTeton49 min
Jul 9, 8:53 AM MDTSpecial Weather StatementTFXTeton52 min
Jul 9, 12:22 PM MDTSpecial Weather StatementTFXLewis and Clark23 min
Jul 9, 12:34 PM MDTSpecial Weather StatementTFXLewis and Clark41 min
Jul 9, 12:52 PM MDTSpecial Weather StatementTFXLewis and Clark23 min
Jul 9, 1:03 PM MDTSpecial Weather StatementTFXMeagher27 min
Jul 9, 1:12 PM MDTSpecial Weather StatementTFXLewis and Clark33 min
Jul 9, 1:31 PM MDTSpecial Weather StatementTFXBlaine29 min
Jul 9, 1:42 PM MDTSpecial Weather StatementTFXBroadwater33 min
Jul 9, 1:55 PM MDTSpecial Weather StatementTFXBlaine35 min
Jul 9, 1:59 PM MDTSpecial Weather StatementTFXCascade31 min
Jul 9, 2:05 PM MDTSpecial Weather StatementTFXGlacier25 min
Jul 9, 2:16 PM MDTSpecial Weather StatementTFXPondera29 min
Jul 9, 2:28 PM MDTSpecial Weather StatementTFXBlaine32 min
Jul 9, 2:44 PM MDTSpecial Weather StatementTFXPondera31 min
Jul 9, 2:46 PM MDTSpecial Weather StatementTFXBlaine29 min
Jul 9, 2:51 PM MDTSpecial Weather StatementTFXGlacier24 min
Jul 9, 3:11 PM MDTSpecial Weather StatementTFXBlaine, Hill34 min
Jul 9, 3:17 PM MDTSpecial Weather StatementTFXPondera28 min
Jul 9, 3:18 PM MDTSpecial Weather StatementTFXGlacier27 min
Jul 9, 3:40 PM MDTSpecial Weather StatementTFXCascade35 min
Jul 9, 3:48 PM MDTSpecial Weather StatementTFXPondera27 min
Jul 9, 3:52 PM MDTSpecial Weather StatementTFXBlaine, Hill38 min
Jul 9, 4:14 PM MDTSpecial Weather StatementTFXPondera31 min
Jul 9, 4:20 PM MDTSpecial Weather StatementTFXBlaine, Hill40 min
Jul 9, 4:59 PM MDTSpecial Weather StatementTFXChouteau46 min
Jul 9, 5:43 PM MDTSpecial Weather StatementTFX32 min

Nearby

Special Weather Statements in Montana, 2021Every 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.