Alert archive / Montana / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 593

July 19, 200119 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 19, 2001, 7:15 PM MDT for 19 counties in Montana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 19, 2001, 7:15 PM MDT (01:15 UTC)
Expired
Jul 19, 2001, 11:00 PM MDT
In force
4 hr
Issued by
the Storm Prediction Center

Counties Big Horn County, MT, Carbon County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Yellowstone County, MT

The radar

The Billings radar (KBLX), 133 km from the middle of the area, began a volume at 01:17 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

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

IssuedProductOfficeCountiesLasted
Jul 19, 7:15 PM MDTSevere Thunderstorm WarningBYZYellowstone60 min
Jul 19, 7:42 PM MDTSevere Thunderstorm WarningBYZMusselshell, Yellowstone63 min
Jul 19, 8:41 PM MDTSevere Thunderstorm WarningBYZTreasure34 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.3 hours before the alert went out and 185 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 2001-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 667 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 2001-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -52 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
667 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
1843 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-52 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-2.2

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 20, 12:30 PM MDTTornado WatchSPCDaniels, Dawson, Garfield, McCone, Richland, Roosevelt and 3 more6 hr
Jul 20, 4:00 PM MDTTornado WatchSPCBig Horn, Carter, Custer, Fallon, Powder River, Prairie and 3 more7 hr
Jul 20, 5:30 PM MDTTornado WatchSPCDaniels, Dawson, Garfield, McCone, Richland, Roosevelt and 2 more6 hr

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.