Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 2, NWS Great Falls, MT

June 4, 2021Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 4, 2021, 9:30 PM MDT for Gallatin County, Montana. It was in force for 33 min. 2 reports 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
Jun 4, 2021, 9:30 PM MDT (03:30 UTC)
Expired
Jun 4, 2021, 10:03 PM MDT
In force
33 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

County Gallatin County, MT

The radar

The Great Falls radar (KTFX), 175 km from the middle of the area, began a volume at 03:32 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
Jun 4, 9:30 PM MDTHAIL 0.57 Ene Manhattan, MTHALF INCH HAIL REPORTED.
Jun 4, 9:42 PM MDTHAIL 0.259 Ne Belgrade, MT

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 00:00Z, 3.5 hours before the alert went out and 178 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 00:00Z on 2021-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 460 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, Great_falls, MT at 00:00Z on 2021-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
460 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
2772 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

848 
WUUS55 KTFX 050330
SVRTFX
MTC031-050415-
/O.NEW.KTFX.SV.W.0002.210605T0330Z-210605T0415Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
930 PM MDT Fri Jun 4 2021

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Northeastern Gallatin County in south central Montana...

* Until 1015 PM MDT.

* At 930 PM MDT, a severe thunderstorm was located near Belgrade, or
  14 miles northwest of Bozeman, moving east 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...
  Belgrade.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Great Falls.

&&

LAT...LON 4591 11133 4609 11079 4582 11079 4574 11125
TIME...MOT...LOC 0330Z 250DEG 31KT 4586 11119 

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

Kredensor
2 follow-up statements
011 
WWUS55 KTFX 050348
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
948 PM MDT Fri Jun 4 2021

MTC031-050415-
/O.CON.KTFX.SV.W.0002.000000T0000Z-210605T0415Z/
Gallatin MT-
948 PM MDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM MDT
FOR NORTHEASTERN GALLATIN COUNTY...

At 947 PM MDT, a severe thunderstorm was located 13 miles northeast
of Belgrade, or 16 miles north of Bozeman, moving east at 35 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
northeastern Gallatin County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Great Falls.

&&

LAT...LON 4579 11105 4596 11114 4608 11079 4584 11079
TIME...MOT...LOC 0347Z 250DEG 31KT 4591 11098 

HAIL...0.88IN
WIND...60MPH
 
$$

Kredensor
798 
WWUS55 KTFX 050403
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
1003 PM MDT Fri Jun 4 2021

MTC031-050413-
/O.CAN.KTFX.SV.W.0002.000000T0000Z-210605T0415Z/
Gallatin MT-
1003 PM MDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN GALLATIN COUNTY
IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 4579 11105 4596 11114 4608 11079 4584 11079
TIME...MOT...LOC 0401Z 250DEG 31KT 4596 11079 

$$

Kredensor

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 4, 7:41 PM MDTSpecial Weather StatementTFXBlaine34 min
Jun 4, 9:22 PM MDTSpecial Weather StatementTFXFergus53 min
Jun 4, 9:36 PM MDTSpecial Weather StatementTFXGallatin24 min
Jun 4, 9:45 PM MDTSevere Thunderstorm WarningTFXFergus45 min
Jun 4, 10:45 PM MDTSpecial Weather StatementTFXFergus45 min
Jun 5, 1:18 PM MDTSpecial Weather StatementTFXMadison27 min
Jun 5, 5:08 PM MDTSpecial Weather StatementTFXJudith Basin37 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.