Alert archive / Montana / Tornado Watches in 1998

Tornado Watch 724

July 4, 199812 counties in Montana

The Storm Prediction Center issued this tornado watch at Jul 4, 1998, 5:30 PM MDT for 12 counties in Montana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 1998, 5:30 PM MDT (23:30 UTC)
Expired
Jul 4, 1998, 11:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center

Counties Big Horn County, MT, Carbon County, MT, Daniels County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Rosebud County, MT, Treasure County, MT, Valley County, MT, Yellowstone County, MT

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 4, 5:39 PM MDTFlash Flood WarningGGWDaniels2 hr
Jul 4, 5:47 PM MDTSevere Thunderstorm WarningGGWDaniels63 min
Jul 4, 5:50 PM MDTSevere Thunderstorm WarningGGWPetroleum65 min
Jul 4, 6:02 PM MDTTornado WarningGGWDaniels48 min
Jul 4, 8:10 PM MDTSevere Thunderstorm WarningBYZGolden Valley, Stillwater, Yellowstone60 min
Jul 4, 8:10 PM MDTSevere Thunderstorm WarningBYZMusselshell60 min
Jul 4, 8:34 PM MDTTornado WarningBYZYellowstone31 min
Jul 4, 8:39 PM MDTSevere Thunderstorm WarningGGWMcCone66 min
Jul 4, 9:13 PM MDTTornado WarningBYZYellowstone27 min
Jul 4, 9:41 PM MDTSevere Thunderstorm WarningBYZYellowstone59 min
Jul 4, 9:49 PM MDTSevere Thunderstorm WarningBYZRosebud61 min
Jul 4, 9:55 PM MDTSevere Thunderstorm WarningBYZBig Horn60 min
Jul 4, 10:00 PM MDTSevere Thunderstorm WarningGGWValley65 min
Jul 4, 10:49 PM MDTSevere Thunderstorm WarningBYZRosebud61 min
Jul 4, 10:56 PM MDTSevere Thunderstorm WarningBYZBig Horn, Treasure64 min

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.5 hours before the alert went out and 236 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 1998-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 149 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 1998-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
149 J/kg
Mixed-layer CIN
-293 J/kg
Mixed-layer LCL
1077 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 3, 7:00 PM MDTSevere Thunderstorm WatchSPCBroadwater, Cascade, Chouteau, Glacier, Hill, Judith Basin and 7 more5 hr
Jul 3, 10:45 PM MDTSevere Thunderstorm WatchSPCBlaine, Fergus, Garfield, Petroleum, Phillips, Valley4 hr
Jul 4, 2:30 PM MDTSevere Thunderstorm WatchSPCBeaverhead, Blaine, Broadwater, Cascade, Chouteau, Deer Lodge and 19 more7 hr

Nearby

Tornado Watches in Montana, 1998Every tornado watch in 1998

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.