Alert archive / Montana / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 712

August 5, 200423 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Aug 5, 2004, 1:00 PM MDT for 23 counties in Montana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 5, 2004, 1:00 PM MDT (19:00 UTC)
Expired
Aug 5, 2004, 7:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
All 23 counties

Beaverhead County, MT, Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Deer Lodge County, MT, Gallatin County, MT, Glacier County, MT, Granite County, MT, Hill County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Liberty County, MT, Madison County, MT, Meagher County, MT, Park County, MT, Pondera County, MT, Powell County, MT, Silver Bow County, MT, Sweet Grass County, MT, Teton County, MT, Toole County, MT, Wheatland County, MT

The radar

The Great Falls radar (KTFX), 20 km from the middle of the area, began a volume at 19:00 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.

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 5, 3:15 PM MDTSevere Thunderstorm WarningTFXLewis and Clark30 min
Aug 5, 3:39 PM MDTSevere Thunderstorm WarningTFXCascade51 min
Aug 5, 4:10 PM MDTSevere Thunderstorm WarningTFXCascade50 min
Aug 5, 4:48 PM MDTSevere Thunderstorm WarningTFXChouteau, Judith Basin57 min
Aug 5, 4:57 PM MDTSevere Thunderstorm WarningTFXMeagher48 min
Aug 5, 5:01 PM MDTSevere Thunderstorm WarningTFXToole29 min
Aug 5, 5:45 PM MDTSevere Thunderstorm WarningTFXLiberty, Toole45 min
Aug 5, 5:58 PM MDTSevere Thunderstorm WarningTFXChouteau32 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 7.0 hours before the alert went out and 67 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, Great_falls, MT at 12:00Z on 2004-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 111 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, Great_falls, MT at 12:00Z on 2004-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
111 J/kg
Mixed-layer CIN
-386 J/kg
Mixed-layer LCL
1565 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 5, 12:35 PM MDTMesoscale DiscussionSPCBeaverhead, Broadwater, Cascade, Deer Lodge, Flathead, Gallatin and 12 more2 hr
Aug 5, 3:30 PM MDTSevere Thunderstorm WatchSPCBig Horn, Carbon, Golden Valley, Musselshell, Rosebud, Stillwater and 2 more6 hr
Aug 5, 4:06 PM MDTMesoscale DiscussionSPCBeaverhead, Broadwater, Cascade, Chouteau, Deer Lodge, Gallatin and 16 more84 min
Aug 5, 5:05 PM MDTSevere Thunderstorm WatchSPCBlaine, Daniels, Dawson, Fergus, Garfield, McCone and 6 more8 hr
Aug 5, 5:20 PM MDTMesoscale DiscussionSPCBig Horn, Carbon, Golden Valley, Musselshell, Rosebud, Stillwater and 2 more85 min

Nearby

Severe Thunderstorm Watches in Montana, 2004Every severe thunderstorm watch in 2004

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.