Alert archive / Montana / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 494

July 4, 20028 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 4, 2002, 9:30 PM MDT for 8 counties in Montana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2002, 9:30 PM MDT (03:30 UTC)
Expired
Jul 5, 2002, 2:00 AM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 4, 9:57 PM MDTSevere Thunderstorm WarningGGWValley63 min
Jul 4, 10:06 PM MDTSevere Thunderstorm WarningGGWMcCone54 min
Jul 4, 10:40 PM MDTSevere Thunderstorm WarningGGWRoosevelt65 min
Jul 4, 10:58 PM MDTSevere Thunderstorm WarningGGWMcCone62 min
Jul 4, 11:43 PM MDTSevere Thunderstorm WarningGGWDawson, Richland62 min
Jul 4, 11:48 PM MDTSevere Thunderstorm WarningGGWRoosevelt57 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 3.5 hours before the alert went out and 71 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, Glasgow Intl Airport, MT at 00:00Z on 2002-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1143 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, Glasgow Intl Airport, MT at 00:00Z on 2002-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
1143 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
2490 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 6:00 PM MDTSevere Thunderstorm WatchSPCBlaine, Broadwater, Daniels, Fergus, Garfield, Golden Valley and 7 more5 hr

Nearby

Severe Thunderstorm Watches in Montana, 2002Every severe thunderstorm watch in 2002

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.