Alert archive / Montana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 7, NWS Billings, MT

May 20, 2020Golden Valley County, Musselshell County, Montana

NWS Billings, MT issued this severe thunderstorm warning at May 20, 2020, 12:55 AM MDT for Golden Valley County, Musselshell County, Montana. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 20, 2020, 12:55 AM MDT (06:55 UTC)
Expired
May 20, 2020, 1:45 AM MDT
In force
50 min
Issued by
NWS Billings, MT
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Golden Valley County, MT, Musselshell County, MT

The radar

The Billings radar (KBLX), 67 km from the middle of the area, began a volume at 06:54 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 00:00Z, 6.9 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 2020-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2020-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1347 m above ground
0-6 km bulk shear
80 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
386 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Billings, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 19, 9:40 PM MDT, 3 hours 15 minutes earlier.

Area forecast discussion, May 19, 9:40 PM MDT, 3 hours 15 minutes before
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Hazardous weather outlook, May 19, 2:43 PM MDT, 10 hours 12 minutes before
Hazardous Weather Outlook
National Weather Service Billings MT
243 PM MDT Tue May 19 2020

MTZ029>034-036-037-040-042-056>058-063>068-138-139-141-169>173-228-
235-WYZ198-199-202045-
Musselshell-Treasure-Northern Rosebud-Custer-Fallon-
Northern Stillwater-Powder River-Carter-Northern Park-
Golden Valley-Red Lodge Foothills-Northern Big Horn-
Southern Rosebud-Judith Gap-Paradise Valley-Livingston Area-
Beartooth Foothills-Absaroka/Beartooth Mountains-Crazy Mountains-
Southern Big Horn-Southeastern Carbon-Northern Sweet Grass-
Bighorn Canyon-Northern Carbon-Pryor/Northern Bighorn Mountains-
Melville Foothills-Northeastern Yellowstone-Southern Wheatland-
Southwestern Yellowstone-Northeast Bighorn Mountains-
Sheridan Foothills-
243 PM MDT Tue May 19 2020

This Hazardous Weather Outlook is for portions of central
Montana...south central Montana...southeast Montana and north
central Wyoming.

* WHAT...Strong to severe thunderstorms Wednesday.

* WHERE...Greatest risk of severe storms is along and east of a
  line from Miles City to Broadus. Large hail, strong winds and
  heavy rain are possible in this area. To the west, there is a
  good chance of showers through the day, and cannot rule out a
  couple of strong thunderstorms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Hazardous Weather Outlook is issued when hazardous weather could
impact the region within the next week. Be sure to stay tuned for
future updates as locations, timing, and impacts could change.
Begin preparations to mitigate any impacts that could result from
the hazardous weather.

&&

In the hours before

Local storm report, May 19, 9:08 PM MDT, 3 hours 47 minutes before
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Local storm report, May 19, 9:21 PM MDT, 3 hours 34 minutes before
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Local storm report, May 19, 9:40 PM MDT, 3 hours 15 minutes before
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Local storm report, May 19, 9:51 PM MDT, 3 hours 4 minutes before
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Special weather statement, May 19, 11:41 PM MDT, 1 hour 14 minutes before
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Special weather statement, May 20, 12:29 AM MDT, 26 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 6:44 PM MDTSpecial Weather StatementBYZWheatland46 min
May 19, 6:45 PM MDTSpecial Weather StatementBYZWheatland30 min
May 19, 7:24 PM MDTSevere Thunderstorm WarningBYZWheatland66 min
May 19, 8:01 PM MDTSevere Thunderstorm WarningBYZGolden Valley59 min
May 19, 8:46 PM MDTSpecial Weather StatementBYZSweet Grass29 min
May 19, 8:55 PM MDTSevere Thunderstorm WarningBYZMusselshell35 min
May 19, 11:41 PM MDTSpecial Weather StatementBYZStillwater, Sweet Grass49 min
May 20, 12:29 AM MDTSpecial Weather StatementBYZGolden Valley46 min
May 20, 1:45 AM MDTSpecial Weather StatementBYZMusselshell45 min
May 20, 3:57 PM MDTSpecial Weather StatementBYZWheatland48 min
May 20, 4:21 PM MDTSevere Thunderstorm WarningBYZCuster24 min
May 20, 4:42 PM MDTSevere Thunderstorm WarningBYZCuster48 min
May 20, 4:47 PM MDTSpecial Weather StatementBYZGolden Valley43 min
May 20, 4:48 PM MDTSpecial Weather StatementBYZBig Horn42 min
May 20, 5:13 PM MDTSpecial Weather StatementBYZCarter32 min
May 20, 5:23 PM MDTSevere Thunderstorm WarningBYZCuster67 min
May 20, 5:29 PM MDTSpecial Weather StatementBYZMusselshell46 min
May 20, 5:36 PM MDTSpecial Weather StatementBYZRosebud24 min
May 20, 5:44 PM MDTSpecial Weather StatementBYZCarter46 min

Nearby

Severe Thunderstorm Warnings in Montana, 2020Every severe thunderstorm warning 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.