Alert archive / Montana / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 138, NWS Great Falls, MT

September 17, 2013Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Sep 17, 2013, 4:04 PM MDT for Gallatin County, Montana. It was in force for 41 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: Sep 17, 2013, 4:04 PM MDT (22:04 UTC)
Expired: Sep 17, 2013, 4:45 PM MDT
In force: 41 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon

County Gallatin County, MT

The radar

The Billings radar (KBLX), 202 km from the middle of the area, began a volume at 22:07 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

Riverton, WY (KRIW), launched 12:00Z, 10.1 hours before the alert went out and 352 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: 271 J/kg
Mixed-layer CIN: -142 J/kg
Mixed-layer LCL: 2086 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 96 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 Sep 17, 3:16 PM MDT, 48 minutes earlier.

Area forecast discussion, Sep 17, 3:16 PM MDT, 48 minutes before

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Hazardous weather outlook, Sep 17, 4:43 AM MDT, 11 hours 21 minutes before

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In the hours before

Special weather statement, Sep 17, 2:13 PM MDT, 1 hour 51 minutes before

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Special weather statement, Sep 17, 2:56 PM MDT, 1 hour 8 minutes before

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Special weather statement, Sep 17, 4:01 PM MDT, 3 minutes before

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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
Sep 16, 6:17 PM MDT	Special Weather Statement	TFX	Blaine	43 min
Sep 16, 6:53 PM MDT	Special Weather Statement	TFX	Blaine	52 min
Sep 16, 11:52 PM MDT	High Wind Warning	TFX		5 hr
Sep 17, 7:23 AM MDT	Special Weather Statement	TFX	Beaverhead	52 min
Sep 17, 2:13 PM MDT	Special Weather Statement	TFX	Beaverhead	47 min
Sep 17, 2:56 PM MDT	Special Weather Statement	TFX	Madison	34 min
Sep 17, 3:12 PM MDT	Flash Flood Watch	TFX		8 hr
Sep 17, 4:01 PM MDT	Special Weather Statement	TFX		44 min
Sep 17, 4:15 PM MDT	Special Weather Statement	TFX	Gallatin	45 min

Nearby

Severe Thunderstorm Warnings in Montana, 2013 Every severe thunderstorm warning in 2013

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.