Alert archive / Montana / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 52, NWS Great Falls, MT

July 12, 2009Madison County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 12, 2009, 3:30 PM MDT for Madison County, Montana. It was in force for 32 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
Jul 12, 2009, 3:30 PM MDT (21:30 UTC)
Expired
Jul 12, 2009, 4:02 PM MDT
In force
32 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon

County Madison County, MT

The radar

The Great Falls radar (KTFX), 244 km from the middle of the area, began a volume at 21:31 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, 9.5 hours before the alert went out and 375 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, Riverton, WY at 12:00Z on 2009-07-12Temperature 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 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2009-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 square meters per square second.193958Sfc1 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
2818 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 1:27 PM MDTSpecial Weather StatementTFXBeaverhead48 min
Jul 12, 1:54 PM MDTSpecial Weather StatementTFXLewis and Clark66 min
Jul 12, 2:37 PM MDTSpecial Weather StatementTFXBeaverhead, Madison38 min
Jul 12, 2:45 PM MDTSevere Thunderstorm WarningTFXMadison25 min
Jul 12, 2:52 PM MDTSevere Thunderstorm WarningTFXCascade, Lewis and Clark38 min
Jul 12, 3:30 PM MDTSevere Thunderstorm WarningTFXCascade, Chouteau, Lewis and Clark, Teton45 min
Jul 12, 3:37 PM MDTSevere Thunderstorm WarningTFXGallatin38 min
Jul 12, 4:04 PM MDTSpecial Weather StatementTFXGallatin16 min
Jul 12, 4:13 PM MDTSpecial Weather StatementTFXChouteau47 min
Jul 12, 4:19 PM MDTSpecial Weather StatementTFXBeaverhead41 min
Jul 12, 4:26 PM MDTSpecial Weather StatementTFXGallatin34 min
Jul 12, 5:01 PM MDTSpecial Weather StatementTFXMadison44 min
Jul 12, 5:09 PM MDTSpecial Weather StatementTFXChouteau66 min
Jul 12, 5:31 PM MDTSpecial Weather StatementTFXMadison44 min
Jul 12, 5:40 PM MDTSevere Thunderstorm WarningTFXMadison50 min
Jul 12, 5:47 PM MDTSpecial Weather StatementTFXMadison43 min

Nearby

Severe Thunderstorm Warnings in Montana, 2009Every severe thunderstorm warning in 2009

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.