Alert archive / Montana / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 565

July 17, 200120 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 17, 2001, 4:30 PM MDT for 20 counties in Montana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 17, 2001, 4:30 PM MDT (22:30 UTC)
Expired
Jul 17, 2001, 10:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center

Counties Big Horn County, MT, Blaine County, MT, Carbon County, MT, Custer County, MT, Daniels County, MT, Fergus County, MT, Garfield County, MT, Golden Valley County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Powder River County, MT, Prairie County, MT, Roosevelt County, MT, Rosebud County, MT, Stillwater County, MT, Treasure County, MT, Valley County, MT, Yellowstone County, MT

The radar

The Billings radar (KBLX), 109 km from the middle of the area, began a volume at 22:32 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

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

IssuedProductOfficeCountiesLasted
Jul 17, 4:54 PM MDTSevere Thunderstorm WarningBYZYellowstone66 min
Jul 17, 4:58 PM MDTSevere Thunderstorm WarningTFXFergus27 min
Jul 17, 5:29 PM MDTFlash Flood WarningBYZYellowstone2 hr
Jul 17, 5:36 PM MDTSevere Thunderstorm WarningGGWPhillips54 min
Jul 17, 6:34 PM MDTSevere Thunderstorm WarningBYZRosebud56 min
Jul 17, 6:40 PM MDTSevere Thunderstorm WarningBYZBig Horn65 min
Jul 17, 7:53 PM MDTSevere Thunderstorm WarningGGWGarfield67 min
Jul 17, 8:58 PM MDTSevere Thunderstorm WarningGGWGarfield, McCone, Prairie62 min
Jul 17, 9:57 PM MDTSevere Thunderstorm WarningGGWDawson, McCone, Prairie63 min

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.5 hours before the alert went out and 230 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 2001-07-17Temperature 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 2001-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
1066 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-67 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.

Nearby

Severe Thunderstorm Watches in Montana, 2001Every severe thunderstorm watch in 2001

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.