Alert archive / Montana / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 12, NWS Great Falls, MT

May 31, 2018Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at May 31, 2018, 2:33 PM MDT for Gallatin County, Montana. It was in force for 13 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 31, 2018, 2:33 PM MDT (20:33 UTC)
Expired: May 31, 2018, 2:46 PM MDT
In force: 13 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Gallatin County, MT

The radar

The Billings radar (KBLX), 202 km from the middle of the area, began a volume at 20:35 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 31, 1:50 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.6 hours before the alert went out and 218 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 892 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 50 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 Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 31, 12:00 PM MDT, 2 hours 33 minutes earlier.

Area forecast discussion, May 31, 12:00 PM MDT, 2 hours 33 minutes before

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In the hours before

Special weather statement, May 31, 1:58 PM MDT, 35 minutes before

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Special weather statement, May 31, 2:18 PM MDT, 15 minutes before

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Local storm report, May 31, 2:26 PM MDT, 7 minutes before

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Local storm report, May 31, 2:29 PM MDT, 4 minutes before

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Local storm report, May 31, 2:33 PM MDT, 0 minutes before

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        Please try again in a few minutes.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

Issued	Product	Office	Counties	Lasted
May 30, 6:14 PM MDT	Areal Flood Advisory	TFX	Fergus	2 hr
May 30, 6:25 PM MDT	Special Weather Statement	TFX	Cascade	35 min
May 30, 10:44 PM MDT	Special Weather Statement	TFX	Ravalli	31 min
May 30, 11:14 PM MDT	Special Weather Statement	TFX	Deer Lodge	31 min
May 31, 4:13 AM MDT	Flood Watch	TFX		28 hr
May 31, 1:58 PM MDT	Special Weather Statement	TFX	Gallatin	47 min
May 31, 2:18 PM MDT	Special Weather Statement	TFX	Fergus	42 min
May 31, 3:05 PM MDT	Special Weather Statement	TFX	Lewis and Clark	25 min
May 31, 3:26 PM MDT	Areal Flood Advisory	TFX	Fergus, Judith Basin	3 hr
May 31, 3:26 PM MDT	Special Weather Statement	TFX	Lewis and Clark	34 min
May 31, 3:42 PM MDT	Special Weather Statement	TFX	Lewis and Clark	33 min
May 31, 3:45 PM MDT	Areal Flood Advisory	TFX	Lewis and Clark	3 hr
May 31, 4:11 PM MDT	Special Weather Statement	TFX	Chouteau	34 min
May 31, 4:14 PM MDT	Special Weather Statement	TFX	Lewis and Clark	31 min
May 31, 4:39 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Lewis and Clark	36 min
May 31, 5:57 PM MDT	Special Weather Statement	TFX		48 min

Nearby

Severe Thunderstorm Warnings in Montana, 2018 Every severe thunderstorm warning in 2018

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.