Alert archive / Montana / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 120, NWS Great Falls, MT

August 18, 2007Gallatin County, Madison County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 18, 2007, 4:32 PM MDT for Gallatin County, Madison County, Montana. It was in force for 43 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: Aug 18, 2007, 4:32 PM MDT (22:32 UTC)
Expired: Aug 18, 2007, 5:15 PM MDT
In force: 43 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

Counties Gallatin County, MT, Madison County, MT

The radar

The Great Falls radar (KTFX), 227 km from the middle of the area, began a volume at 22:33 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, 10.5 hours before the alert went out and 362 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: 1841 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 66 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 Aug 18, 4:00 PM MDT, 32 minutes earlier.

Area forecast discussion, Aug 18, 4:00 PM MDT, 32 minutes before

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Hazardous weather outlook, Aug 18, 4:08 PM MDT, 24 minutes before

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In the hours before

Local storm report, Aug 18, 2:59 PM MDT, 1 hour 33 minutes before

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Local storm report, Aug 18, 3:19 PM MDT, 1 hour 13 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
Aug 17, 9:45 PM MDT	Severe Thunderstorm Warning	TFX	Hill	60 min
Aug 17, 10:47 PM MDT	Severe Thunderstorm Warning	TFX	Hill	58 min
Aug 18, 4:15 AM MDT	Fire Weather Watch	TFX	Blaine, Broadwater, Cascade, Chouteau, Fergus, Gallatin and 12 more	11 hr
Aug 18, 2:42 PM MDT	Red Flag Warning	TFX	Blaine, Broadwater, Cascade, Chouteau, Fergus, Gallatin and 12 more	33 hr
Aug 18, 3:47 PM MDT	Severe Thunderstorm Warning	TFX	Madison	43 min

Nearby

Severe Thunderstorm Warnings in Montana, 2007 Every severe thunderstorm warning in 2007

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.