Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 129, NWS Glasgow, MT

July 21, 2001Dawson County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 21, 2001, 11:14 PM MDT for Dawson County, Montana. It was in force for 61 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 21, 2001, 11:14 PM MDT (05:14 UTC)
Expired: Jul 22, 2001, 12:15 AM MDT
In force: 61 min
Issued by: NWS Glasgow, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Dawson County, MT

What was reported inside it

Time	Report	Where	Remark
Jul 21, 11:15 PM MDT	Thunderstorm Wind	Glendive, MT	Strong downburst winds caused damage to a roof on a farm.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 21, 7:45 PM MDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 5.2 hours before the alert went out and 166 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 9:20 PM MDT, 1 hour 54 minutes earlier.

Area forecast discussion, Jul 21, 9:20 PM MDT, 1 hour 54 minutes before

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In the hours before

Special weather statement, Jul 21, 9:04 PM MDT, 2 hours 10 minutes before

MTZ016-017-059>061-220335-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
904 PM MDT SAT JUL 21 2001

THE NATIONAL WEATHER SERVICE HAS CLEARED THE FOLLOWING AREAS
REMAINING IN TORNADO WATCH.

IN NORTHEAST MONTANA:

PHILLIPS AND VALLEY COUNTIES.

THIS INCLUDES THE CITIES OF GLASGOW...MALTA...OPHEIM...WHITEWATER...
AND ZORTMAN.

The office that day

Everything else NWS Glasgow, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 6:22 PM MDT	Severe Thunderstorm Warning	GGW	Petroleum	68 min
Jul 21, 6:29 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	61 min
Jul 21, 6:53 PM MDT	Severe Thunderstorm Warning	GGW	Valley	67 min
Jul 21, 7:06 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	69 min
Jul 21, 8:13 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	62 min
Jul 21, 8:53 PM MDT	Severe Thunderstorm Warning	GGW	McCone	67 min
Jul 21, 8:55 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt	65 min
Jul 21, 9:00 PM MDT	Severe Thunderstorm Warning	GGW	Petroleum	60 min
Jul 21, 9:13 PM MDT	Flash Flood Warning	GGW	Garfield	6 hr
Jul 21, 9:17 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	58 min
Jul 21, 9:28 PM MDT	Flash Flood Warning	GGW	McCone	6 hr
Jul 21, 9:47 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	58 min
Jul 21, 9:54 PM MDT	Severe Thunderstorm Warning	GGW	Richland	66 min
Jul 21, 9:57 PM MDT	Severe Thunderstorm Warning	GGW	McCone	63 min
Jul 21, 10:00 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt	60 min
Jul 21, 10:07 PM MDT	Severe Thunderstorm Warning	GGW	Dawson	68 min
Jul 21, 10:32 PM MDT	Flash Flood Warning	GGW	Roosevelt	6 hr
Jul 21, 10:50 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	55 min
Jul 21, 10:53 PM MDT	Flash Flood Warning	GGW	Dawson, Richland	6 hr
Jul 21, 11:00 PM MDT	Severe Thunderstorm Warning	GGW	Richland, Roosevelt	60 min
Jul 21, 11:22 PM MDT	Severe Thunderstorm Warning	GGW	Wibaux	53 min
Jul 22, 2:35 AM MDT	Flash Flood Warning	GGW	Prairie	6 hr
Jul 22, 5:58 PM MDT	Severe Thunderstorm Warning	GGW	Sheridan	32 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001 Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.