Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 19, NWS Great Falls, MT

July 4, 2021Gallatin County, Madison County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 4, 2021, 6:26 PM MDT for Gallatin County, Madison County, Montana. It was in force for 19 min. 5 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
Jul 4, 2021, 6:26 PM MDT (00:26 UTC)
Expired
Jul 4, 2021, 6:45 PM MDT
In force
19 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Gallatin County, MT, Madison County, MT

The radar

The Billings radar (KBLX), 190 km from the middle of the area, began a volume at 00:29 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 4, 6:26 PM MDTTSTM WND GST 603 Ene Bozeman Hot Sprin, MTALSO, PEA-SIZED HAIL.
Jul 4, 6:30 PM MDTTSTM WND GST 565 Ene Bozeman, MT56 MPH WIND GUST.
Jul 4, 6:30 PM MDTHAIL 0.755 Se Belgrade, MTWITH HEAVY DOWNPOUR.
Jul 4, 6:40 PM MDTHAIL 0.53 S Bozeman, MTPHOTO CONFIRMED HALF INCH HAIL.
Jul 4, 6:42 PM MDTTSTM WND GST 5512 E Bozeman, MTMESONET STATION MTBZH BOZEMAN PASS (MT DOT).

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, 0.4 hours before the alert went out and 204 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 2021-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 00:00Z on 2021-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
2 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
4341 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

811 
WUUS55 KTFX 050026
SVRTFX
MTC031-057-050045-
/O.NEW.KTFX.SV.W.0019.210705T0026Z-210705T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
626 PM MDT Sun Jul 4 2021

The National Weather Service in Great Falls has issued a

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

* Until 645 PM MDT.

* At 626 PM MDT, a severe thunderstorm was located near Bozeman,
  moving east at 55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Bozeman, Belgrade, Manhattan, Four Corners, Amsterdam, Bozeman Hot
  Springs, Gallatin Gateway and Church Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4567 11147 4591 11139 4588 11079 4560 11080
      4559 11083 4559 11086 4552 11087 4552 11091
      4550 11092
TIME...MOT...LOC 0026Z 285DEG 49KT 4571 11092 

HAIL...<.75IN
WIND...60MPH
 
$$

SC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 6:34 PM MDTSpecial Weather StatementTFXGallatin26 min
Jul 4, 6:44 PM MDTSevere Thunderstorm WarningTFXGallatin16 min
Jul 4, 6:48 PM MDTSpecial Weather StatementTFXJudith Basin27 min
Jul 4, 7:01 PM MDTSpecial Weather StatementTFXGallatin44 min
Jul 4, 7:13 PM MDTSpecial Weather StatementTFXJudith Basin32 min
Jul 4, 7:24 PM MDTSpecial Weather StatementTFXFergus36 min
Jul 4, 7:56 PM MDTSpecial Weather StatementTFXFergus34 min
Jul 4, 8:28 PM MDTSpecial Weather StatementTFXFergus32 min
Jul 4, 9:29 PM MDTSpecial Weather StatementTFXMeagher31 min
Jul 5, 2:59 PM MDTSpecial Weather StatementTFXJefferson31 min
Jul 5, 3:31 PM MDTSpecial Weather StatementTFXJefferson29 min
Jul 5, 4:27 PM MDTSpecial Weather StatementTFXJefferson33 min
Jul 5, 5:06 PM MDTSpecial Weather StatementTFXSilver Bow24 min
Jul 5, 5:10 PM MDTSpecial Weather StatementTFXLewis and Clark35 min
Jul 5, 5:57 PM MDTSpecial Weather StatementTFXMadison33 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.