Alert archive / Montana / Severe Thunderstorm Watches in 1997

Severe Thunderstorm Watch 718

August 29, 19974 counties in Montana; 4 counties in North Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 29, 1997, 1:00 AM MDT for 4 counties in Montana; 4 counties in North Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 29, 1997, 1:00 AM MDT (07:00 UTC)
Expired
Aug 29, 1997, 6:00 AM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties McCone County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Burke County, ND, Divide County, ND, McKenzie County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 151 km from the middle of the area, began a volume at 07:01 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

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

IssuedProductOfficeCountiesLasted
Aug 29, 1:13 AM MDTSevere Thunderstorm WarningGGWRoosevelt62 min
Aug 29, 2:06 AM MDTSevere Thunderstorm WarningGGWRoosevelt, Sheridan69 min

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 7.0 hours before the alert went out and 452 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 00:00Z on 1997-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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 00:00Z on 1997-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939587897Sfc1 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
52 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
3129 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Aug 28, 8:15 PM MDTSevere Thunderstorm WatchSPCBlaine, Carbon, Daniels, Fergus, Garfield, Golden Valley and 10 more6 hr

Nearby

Severe Thunderstorm Watches in Montana, 1997Severe Thunderstorm Watches in North Dakota, 1997Every severe thunderstorm watch in 1997

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.