Alert archive / Montana / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 55, NWS Great Falls, MT

July 12, 2009Hill County, Liberty County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 12, 2009, 6:09 PM MDT for Hill County, Liberty County, Montana. It was in force for 42 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, 6:09 PM MDT (00:09 UTC)
Expired
Jul 12, 2009, 6:51 PM MDT
In force
42 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon

Counties Hill County, MT, Liberty County, MT

The radar

The Great Falls radar (KTFX), 140 km from the middle of the area, began a volume at 00:12 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

Spokane, WA (KOTX), launched 00:00Z, 0.2 hours before the alert went out and 444 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, Spokane, WA at 00:00Z on 2009-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 191 joules per kilogram.LCLLFCEL10008507005003002001001 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, Spokane, WA at 00:00Z on 2009-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.19395878Sfc1 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
191 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
2984 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

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, 6:13 PM MDTSevere Thunderstorm WarningTFXGallatin37 min
Jul 12, 6:18 PM MDTSpecial Weather StatementTFXBlaine57 min
Jul 12, 7:53 PM MDTSpecial Weather StatementTFXBlaine52 min
Jul 13, 9:45 AM MDTSpecial Weather StatementTFXGlacier60 min
Jul 13, 9:55 AM MDTSpecial Weather StatementTFXCascade65 min
Jul 13, 9:57 AM MDTSpecial Weather StatementTFXBroadwater63 min
Jul 13, 10:19 AM MDTSevere Thunderstorm WarningTFXBroadwater, Cascade, Lewis and Clark, Meagher41 min
Jul 13, 10:56 AM MDTSevere Thunderstorm WarningTFXCascade22 min
Jul 13, 11:02 AM MDTSpecial Weather StatementTFXPondera43 min
Jul 13, 11:25 AM MDTSevere Thunderstorm WarningTFXPondera, Teton50 min
Jul 13, 11:31 AM MDTSpecial Weather StatementTFXBroadwater44 min
Jul 13, 11:46 AM MDTSpecial Weather StatementTFXChouteau44 min
Jul 13, 11:52 AM MDTSevere Thunderstorm WarningTFXPondera38 min
Jul 13, 12:17 PM MDTSpecial Weather StatementTFXChouteau58 min
Jul 13, 12:21 PM MDTSevere Thunderstorm WarningTFXPondera, Toole39 min
Jul 13, 12:40 PM MDTSpecial Weather StatementTFXToole50 min
Jul 13, 1:04 PM MDTSpecial Weather StatementTFXHill56 min
Jul 13, 1:04 PM MDTSevere Thunderstorm WarningTFXLiberty, Toole41 min
Jul 13, 1:23 PM MDTSpecial Weather StatementTFXBroadwater52 min
Jul 13, 1:46 PM MDTSevere Thunderstorm WarningTFXLiberty24 min
Jul 13, 2:13 PM MDTSpecial Weather StatementTFXMeagher47 min
Jul 13, 2:14 PM MDTSpecial Weather StatementTFXFergus46 min
Jul 13, 2:15 PM MDTSpecial Weather StatementTFXBlaine45 min
Jul 13, 2:27 PM MDTSpecial Weather StatementTFXFergus48 min
Jul 13, 2:37 PM MDTSevere Thunderstorm WarningTFXBlaine, Fergus38 min
Jul 13, 2:44 PM MDTSpecial Weather StatementTFXBroadwater46 min
Jul 13, 2:53 PM MDTSevere Thunderstorm WarningTFXCascade, Judith Basin, Meagher52 min
Jul 13, 2:53 PM MDTSevere Thunderstorm WarningTFXBlaine52 min
Jul 13, 4:22 PM MDTSpecial Weather StatementTFXBroadwater38 min
Jul 13, 4:49 PM MDTSpecial Weather StatementTFXJefferson41 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.