Alert archive / Montana / Mesoscale Discussions in 2003

Mesoscale Discussion 2117

August 7, 200318 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2003, 2:18 PM MDT for 18 counties in Montana. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Aug 7, 2003, 2:18 PM MDT (20:18 UTC)
Expired
Aug 7, 2003, 4:15 PM MDT
In force
117 min
Issued by
the Storm Prediction Center

Counties Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Deer Lodge County, MT, Gallatin County, MT, Granite County, MT, Jefferson County, MT, Judith Basin County, MT, Lake County, MT, Lewis and Clark County, MT, Meagher County, MT, Missoula County, MT, Pondera County, MT, Powell County, MT, Silver Bow County, MT, Sweet Grass County, MT, Teton County, MT, Wheatland County, MT

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.3 hours before the alert went out and 148 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 2003-08-07Temperature 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 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 2003-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -81 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2439 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-81 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 6, 7:25 PM MDTMesoscale DiscussionSPCBlaine, Fergus, Garfield, Golden Valley, Musselshell, Petroleum and 2 more2 hr
Aug 7, 12:16 AM MDTMesoscale DiscussionSPCMcCone, Richland59 min
Aug 7, 3:45 PM MDTSevere Thunderstorm WatchSPCBlaine, Chouteau, Daniels, Dawson, Fergus, Garfield and 14 more6 hr
Aug 7, 5:56 PM MDTMesoscale DiscussionSPCBlaine, Chouteau, Daniels, Dawson, Fergus, Garfield and 14 more2 hr

Nearby

Mesoscale Discussions in Montana, 2003Every mesoscale discussion in 2003

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.