Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 23, NWS Great Falls, MT

July 6, 2021Glacier County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 6, 2021, 4:40 PM MDT for Glacier County, Montana. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 6, 2021, 4:40 PM MDT (22:40 UTC)
Expired
Jul 6, 2021, 5:15 PM MDT
In force
35 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Glacier County, MT

The radar

The Great Falls radar (KTFX), 175 km from the middle of the area, began a volume at 22:40 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.

What was reported inside it

TimeReportWhereRemark
Jul 6, 5:21 PM MDTHAIL 1Santa Rita, MTDAMAGE DONE TO TWO VEHICLES IN SANTA RITA. REPORT TIME WAS ESTIMATED VIA RADAR. DELAYED REPORTED RECEIVED ON 7/7.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.7 hours before the alert went out and 212 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 2021-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 103 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 2021-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
103 J/kg
Mixed-layer CIN
-251 J/kg
Mixed-layer LCL
1154 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

165 
WUUS55 KTFX 062240
SVRTFX
MTC035-062315-
/O.NEW.KTFX.SV.W.0023.210706T2240Z-210706T2315Z/

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

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Northeastern Glacier County in north central Montana...

* Until 515 PM MDT.

* At 439 PM MDT, a severe thunderstorm was located 20 miles northwest
  of Cut Bank, moving southeast at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Santa Rita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4885 11285 4900 11260 4884 11220 4851 11254
TIME...MOT...LOC 2239Z 318DEG 32KT 4883 11266 

HAIL...1.00IN
WIND...60MPH
 
$$

RCG
2 follow-up statements
950 
WWUS55 KTFX 062256
SVSTFX

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

MTC035-062315-
/O.CON.KTFX.SV.W.0023.000000T0000Z-210706T2315Z/
Glacier MT-
456 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MDT
FOR NORTHEASTERN GLACIER COUNTY...

At 456 PM MDT, a severe thunderstorm was located 9 miles northwest of
Cut Bank, moving southeast at 35 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Santa Rita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4876 11277 4895 11247 4884 11220 4851 11254
TIME...MOT...LOC 2256Z 318DEG 32KT 4871 11250 

HAIL...1.25IN
WIND...60MPH
 
$$

RCG
676 
WWUS55 KTFX 062309
SVSTFX

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

MTC035-062315-
/O.CON.KTFX.SV.W.0023.000000T0000Z-210706T2315Z/
Glacier MT-
509 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MDT
FOR EAST CENTRAL GLACIER COUNTY...

At 509 PM MDT, a severe thunderstorm was located over Cut Bank,
moving southeast at 35 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Santa Rita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4875 11263 4891 11238 4884 11220 4855 11250
TIME...MOT...LOC 2309Z 318DEG 32KT 4862 11238 

HAIL...1.25IN
WIND...60MPH
 
$$

RCG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 5, 6:29 PM MDTSpecial Weather StatementTFXGallatin, Madison31 min
Jul 5, 7:04 PM MDTSpecial Weather StatementTFXGallatin26 min
Jul 5, 7:47 PM MDTSpecial Weather StatementTFXBeaverhead28 min
Jul 5, 9:16 PM MDTSpecial Weather StatementTFXGlacier44 min
Jul 5, 9:57 PM MDTSevere Thunderstorm WarningTFXGlacier33 min
Jul 5, 10:25 PM MDTSevere Thunderstorm WarningTFXGlacier, Toole50 min
Jul 5, 11:12 PM MDTSpecial Weather StatementTFXToole63 min
Jul 6, 12:14 AM MDTSpecial Weather StatementTFXLiberty61 min
Jul 6, 12:42 AM MDTSpecial Weather StatementTFXChouteau33 min
Jul 6, 1:15 AM MDTSpecial Weather StatementTFXLiberty60 min
Jul 6, 1:18 AM MDTSpecial Weather StatementTFXChouteau27 min
Jul 6, 1:44 AM MDTSpecial Weather StatementTFXChouteau46 min
Jul 6, 2:22 AM MDTSpecial Weather StatementTFXChouteau38 min
Jul 6, 3:00 AM MDTSpecial Weather StatementTFXChouteau45 min
Jul 6, 3:42 AM MDTSpecial Weather StatementTFXFergus33 min
Jul 6, 4:15 AM MDTSpecial Weather StatementTFXFergus45 min
Jul 6, 3:37 PM MDTSpecial Weather StatementTFXGlacier23 min
Jul 6, 3:55 PM MDTSpecial Weather StatementTFXGlacier35 min
Jul 6, 4:21 PM MDTSpecial Weather StatementTFXGlacier24 min
Jul 6, 4:27 PM MDTSpecial Weather StatementTFXMusselshell33 min
Jul 6, 4:37 PM MDTSpecial Weather StatementTFXFergus23 min
Jul 6, 4:42 PM MDTSpecial Weather StatementTFXBlaine33 min
Jul 6, 5:14 PM MDTSevere Thunderstorm WarningTFXGlacier, Toole31 min
Jul 6, 5:15 PM MDTSpecial Weather StatementTFXBlaine30 min
Jul 6, 5:45 PM MDTSpecial Weather StatementTFXToole30 min
Jul 6, 5:46 PM MDTSevere Thunderstorm WarningTFXBlaine29 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.