Alert archive / Montana / Tornado Warnings in 2001

Tornado Warning 16, NWS Glasgow, MT

July 20, 2001Dawson County, Montana

NWS Glasgow, MT issued this tornado warning at Jul 20, 2001, 6:56 PM MDT for Dawson County, Montana. It was in force for 64 min. 5 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Jul 20, 2001, 6:56 PM MDT (00:56 UTC)
Expired: Jul 20, 2001, 8:00 PM MDT
In force: 64 min
Issued by: NWS Glasgow, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Dawson County, MT

The radar

The Glasgow radar (KGGW), 157 km from the middle of the area, began a volume at 00:57 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.

What was reported inside it

Time	Report	Where	Remark
Jul 20, 7:15 PM MDT	Hail 0.75	Bloomfield, MT
Jul 20, 7:15 PM MDT	Thunderstorm Wind 52 M	Bloomfield, MT
Jul 20, 7:20 PM MDT	Thunderstorm Wind 90 E	Lindsay, MT	The damaging downburst winds that occurred in McCone County continued into Dawson County. Several farms along Highway 200 had significant damage to outbuildings, and well as to equipment. Crops were 100 percent destroyed in a 1 to 5 mile wide swath from 12 m
Jul 20, 7:25 PM MDT	Thunderstorm Wind 52 M	Lambert, MT
Jul 20, 7:53 PM MDT	Tornado F0	Glendive, MT	Tornado reported by Dawson County Sheriffs Department. The tornado occurred in open prairie and did not cause any damage.

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 20, 5:30 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.9 hours before the alert went out and 156 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: 996 J/kg
Mixed-layer CIN: -183 J/kg
Mixed-layer LCL: 1651 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 331 m²/s²
0-3 km storm-relative helicity: 373 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WFUS55 KGGW 210057
TORGGW

MTC021-210200-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GLASGOW MT
656 PM MDT FRI JUL 20 2001

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* TORNADO WARNING FOR...
  DAWSON COUNTY IN NORTHEAST MONTANA

* UNTIL 800 PM MDT

* AT 647 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 15 MILES SOUTHWEST OF RICHEY...OR ABOUT 15 MILES EAST OF
  CIRCLE...MOVING EAST AT 25 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  BLOOMFIELD AT 725 PM MDT
  INTAKE AT 800 PM MDT

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 4754 10535 4722 10540 4720 10528 4700 10530
          4701 10517 4690 10502 4688 10452 4707 10434
          4730 10453 4759 10463 4760 10498 4767 10504
          4767 10535

.END
99
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What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Jul 20, 2:15 PM MDT, 4 hours 41 minutes earlier.

Area forecast discussion, Jul 20, 2:15 PM MDT, 4 hours 41 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
215 PM MDT FRI JUL 20 2001

SW FLOW WITH DISTURBANCES RIPPLING THROUGH THE FLOW WILL CONTINUE AFFECT
THE AREA INTO SATURDAY NIGHT. THIS MEANS SEVERE WEATHER POTENTIAL WILL
CONTINUE. ETA AND AVN IN FAIR AGREEMENT THROUGH THE PERIOD WITH
PLACEMENT OF SYSTEMS. 500 MB VORT LOBE OVER ALBERTA WITH THE TROF
EXTENDING DOWN INTO THE PAC NW LIFTS OUT INTO MANITOBA BY LATE
SUNDAY. AT 00Z MON...LI/S DROP TO BELOW 0 IN A PORTION OF THE CWA WITH
A WEAK UPPER RIDGE PUSHING IN FROM WESTERN MT. JAMBA

EXTENDED...MRF IN DISAGREEMENT WITH ECMWF AND CANADIAN GEM MODELS
BEYOND DAY 4. A REX BLOCK THAT THE MODELS AGREE WITH SUN/MON SPINS
INTO A DIFFERENT SOLUTION BY ALL MODELS BY TUE. MRF PULLS THE
LOW ACROSS MT AND KEEPS THE CHANCES OF THUNDERSTORMS ACROSS THE CWA
THROUGH FRI...WHILE THE CANADIAN AND THE ECMWF BUILD THE RIDGE OVER
MT WITH THE LOW STAYING NEAR THE WEST COAST. WILL KEEP WITH THE
CHANCES OF STORMS THROUGH WED...WITH A MAINLY DRY CONDITIONS FOR THU
AND FRI. JAMBA

KGGW 062/088 064/085 057/082 058/083 058/083 058/084 057/085
     TTTTTBB  764352/7633322
KGDV 065/089 064/085 059/084 059/084 059/084 058/085 057/086
     TTTTTBB  765352/7633322

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 6:15 PM MDT	Tornado Warning	GGW	McCone	60 min
Jul 20, 6:28 PM MDT	Flash Flood Warning	GGW	Garfield, McCone	3 hr
Jul 20, 6:41 PM MDT	Severe Thunderstorm Warning	GGW	Sheridan	64 min
Jul 20, 7:09 PM MDT	Severe Thunderstorm Warning	GGW	Richland	66 min
Jul 20, 7:15 PM MDT	Severe Thunderstorm Warning	GGW	McCone	60 min
Jul 20, 7:24 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt	66 min
Jul 20, 7:25 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	65 min
Jul 20, 7:57 PM MDT	Tornado Warning	GGW	Dawson	63 min
Jul 20, 8:14 PM MDT	Tornado Warning	GGW	Richland	61 min
Jul 20, 8:30 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	60 min
Jul 20, 8:35 PM MDT	Flash Flood Warning	GGW	Dawson, Prairie	6 hr
Jul 20, 8:43 PM MDT	Tornado Warning	GGW	Wibaux	62 min
Jul 20, 9:27 PM MDT	Severe Thunderstorm Warning	GGW	Dawson	63 min
Jul 20, 10:15 PM MDT	Severe Thunderstorm Warning	GGW	Wibaux	60 min
Jul 21, 5:23 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	67 min

Nearby

Tornado Warnings in Montana, 2001 Every tornado warning in 2001 Tornadoes 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; radar from the NEXRAD Level II archive.