Alert archive / Montana / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 606

July 21, 20018 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2001, 7:45 PM MDT for 8 counties in Montana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2001, 7:45 PM MDT (01:45 UTC)
Expired
Jul 22, 2001, 1:00 AM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Daniels County, MT, Dawson County, MT, McCone County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Wibaux County, MT

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 21, 8:53 PM MDTSevere Thunderstorm WarningGGWMcCone67 min
Jul 21, 8:55 PM MDTSevere Thunderstorm WarningGGWRoosevelt65 min
Jul 21, 9:28 PM MDTFlash Flood WarningGGWMcCone6 hr
Jul 21, 9:47 PM MDTSevere Thunderstorm WarningGGWPrairie58 min
Jul 21, 9:54 PM MDTSevere Thunderstorm WarningGGWRichland66 min
Jul 21, 9:57 PM MDTSevere Thunderstorm WarningGGWMcCone63 min
Jul 21, 10:00 PM MDTSevere Thunderstorm WarningGGWRoosevelt60 min
Jul 21, 10:07 PM MDTSevere Thunderstorm WarningGGWDawson68 min
Jul 21, 10:32 PM MDTFlash Flood WarningGGWRoosevelt6 hr
Jul 21, 10:53 PM MDTFlash Flood WarningGGWDawson, Richland6 hr
Jul 21, 11:00 PM MDTSevere Thunderstorm WarningGGWRichland, Roosevelt60 min
Jul 21, 11:14 PM MDTSevere Thunderstorm WarningGGWDawson61 min
Jul 21, 11:22 PM MDTSevere Thunderstorm WarningGGWWibaux53 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.8 hours before the alert went out and 107 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 2001-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 649 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 2001-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
649 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
2545 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

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 21, 6:30 PM MDTTornado WatchSPCBig Horn, Carbon, Carter, Custer, Fallon, Golden Valley and 8 more6 hr
Jul 22, 3:00 PM MDTSevere Thunderstorm WatchSPCBig Horn, Carbon, Carter, Custer, Fallon, Golden Valley and 6 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.