Alert archive / Montana / Tornado Warnings in 2001

Tornado Warning 14, NWS Glasgow, MT

July 20, 2001Garfield County, Montana

NWS Glasgow, MT issued this tornado warning at Jul 20, 2001, 5:30 PM MDT for Garfield County, Montana. It was in force for 60 min. No storm report in the archive falls 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.

The facts

Issued: Jul 20, 2001, 5:30 PM MDT (23:30 UTC)
Expired: Jul 20, 2001, 6:30 PM MDT
In force: 60 min
Issued by: NWS Glasgow, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Garfield County, MT

The radar

The Glasgow radar (KGGW), 72 km from the middle of the area, began a volume at 23:31 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.

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, 12:30 PM MDT	Tornado Watch	SPC	6 hr
Jul 20, 5:30 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 11.5 hours before the alert went out and 73 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: 28 J/kg
Mixed-layer CIN: -349 J/kg
Mixed-layer LCL: 2123 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 133 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WFUS55 KGGW 202330
TORGGW

MTC033-210030-

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

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN GARFIELD COUNTY IN NORTHEAST MONTANA

* UNTIL 630 PM MDT

* AT 530 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 22 MILES NORTHEAST OF HELL CREEK RECREATION AREA...OR ABOUT
  29 MILES SOUTH OF GLASGOW...MOVING EAST AT 15 MPH.

* THE TORNADO PRODUCING STORM WILL REMAIN OVER...
  RURAL NORTHEASTERN GARFIELD COUNTY

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.

THIS WARNING EXTENDS THE TORNADO WARNING PREVIOUSLY ISSUED FOR THE
AREA.

LAT...LON 4776 10662 4765 10695 4721 10705 4714 10640
          4755 10630 4785 10629 4785 10636 4794 10643

.END
99

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, 3 hours 15 minutes earlier.

Area forecast discussion, Jul 20, 2:15 PM MDT, 3 hours 15 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 19, 7:38 PM MDT	Tornado Warning	GGW	Wibaux	67 min
Jul 20, 9:22 AM MDT	Severe Thunderstorm Warning	GGW	Phillips	53 min
Jul 20, 11:47 AM MDT	Severe Thunderstorm Warning	GGW	Phillips	58 min
Jul 20, 12:14 PM MDT	Severe Thunderstorm Warning	GGW	Valley	61 min
Jul 20, 12:53 PM MDT	Severe Thunderstorm Warning	GGW	Daniels, Roosevelt	52 min
Jul 20, 1:14 PM MDT	Severe Thunderstorm Warning	GGW	Sheridan	61 min
Jul 20, 1:15 PM MDT	Severe Thunderstorm Warning	GGW	Valley	60 min
Jul 20, 2:49 PM MDT	Tornado Warning	GGW	Phillips	56 min
Jul 20, 3:25 PM MDT	Tornado Warning	GGW	Valley	65 min
Jul 20, 3:45 PM MDT	Tornado Warning	GGW	Phillips	45 min
Jul 20, 4:30 PM MDT	Tornado Warning	GGW	Garfield, Valley	60 min
Jul 20, 5:16 PM MDT	Tornado Warning	GGW	McCone	59 min
Jul 20, 5:27 PM MDT	Tornado Warning	GGW	Daniels	63 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.