Alert archive / Montana / Tornado Warnings in 2001

Tornado Warning 6, NWS Glasgow, MT

July 17, 2001Roosevelt County, Montana

NWS Glasgow, MT issued this tornado warning at Jul 17, 2001, 11:46 PM MDT for Roosevelt County, Montana. It was in force for 59 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 17, 2001, 11:46 PM MDT (05:46 UTC)
Expired
Jul 18, 2001, 12:45 AM MDT
In force
59 min
Issued by
NWS Glasgow, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Roosevelt County, MT

The radar

The Glasgow radar (KGGW), 153 km from the middle of the area, began a volume at 05:49 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.

IssuedProductOfficeLasted
Jul 17, 10:00 PM MDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 5.8 hours before the alert went out and 151 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 2001-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 339 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 2001-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 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
339 J/kg
Mixed-layer CIN
-104 J/kg
Mixed-layer LCL
2182 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
WFUS55 KGGW 180546
TORGGW

MTC085-180645-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GLASGOW MT
1146 PM MDT TUE JUL 17 2001

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN ROOSEVELT COUNTY IN NORTHEAST MONTANA

* UNTIL 1245 AM MDT

* AT 1139 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 6 MILES WEST OF CULBERTSON...MOVING NORTHEAST AT 25 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  FROID AT MIDNIGHT 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.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 4817 10480 4813 10451 4837 10412 4838 @10450

.END
77

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 17, 8:20 PM MDT, 3 hours 26 minutes earlier.

Area forecast discussion, Jul 17, 8:20 PM MDT, 3 hours 26 minutes before
NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
820 PM MDT TUE JUL 17 2001

...SEVERE THUNDERSTORM WATCH FOR ENTIRE CWA THROUGH 10 PM...

STRONG STORMS CONTINUING OVER WEST CENTRAL PORTIONS OF CWA ATTM.
STRONGEST INSTABILITY REMAINS OVER FAR EASTERN ZONES. WILL BE A RACE
TO SEE IF UPPER LEVEL DYNAMICS CAN MAKE IT THERE BEFORE DIURNAL
COOLING BEGINS. EXPLOSIVE THUNDERSTORM DEVELOPMENT NORTH OF SHERIDAN
COUNTY IN CANADA HAS ME A BIT CONCERNED. INSTABILITY AXIS LIES ALONG
NORTH DAKOTA BORDER SOUTH OF THIS STORM. ALTHOUGH NOT BEING
INDICATED WELL ON RADAR. STORMS JUST NOW BEGINNING TO FIRE OVER
RICHLAND COUNTY (CAN SEE THEM OFF TO THE EAST OUT OF WINDOW). IF
THESE STORMS SHOW THE SAME EXPLOSIVE DEVELOPMENT AS THE CANADIAN
STORM...COULD HAVE A LONGER THAN EXPECTED EVENT. WILL LEAVE
WATCH/ZONE ARRANGEMENT ALONE FOR NOW.   POHL

EXTENDED...UPPER LOW REMAINS OVER ALBERTA UNTIL SAT WHEN IT MOVES
EAST AS AN OPEN TROF. THEN AN UPPER TROF DEVELOPS OVER WEST COAST
OVER THE WEEKEND THAT CONTINUES INTO EARLY NEXT WEEK. EXCEPT FOR A
BRIEF PERIOD ON SUNDAY...ERN MT IS IN SW FLOW ALOFT FOR THE ENTIRE
EXTENDED PERIOD WITH FREQUENT SHORTWAVES. GIVEN THE UNSETTLED
PATTERN...WILL NEED TO MENTION A CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER

KGGW 062/084 060/085 062/082 058/083 056/085 058/084 061/085
      TTTBBBB  793323/7933333
KGDV 063/085 061/085 061/085 057/085 058j/085 058/084 060/084
      TTTBBBB  794423/7933333

In the hours before

Special weather statement, Jul 17, 10:00 PM MDT, 1 hour 46 minutes before
MTZ016-021-059-060-180430-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
1000 PM MDT TUE JUL 17 2001

THE NATIONAL WEATHER SERVICE HAS CLEARED A PORTION OF SEVERE
THUNDERSTORM WATCH NUMBER 565. AREAS CLEARED FROM THE SEVERE
THUNDERSTORM WATCH INCLUDE:

IN NORTHEAST MONTANA:

PETROLEUM             PHILLIPS

THIS INCLUDES THE CITIES OF MALTA...WHITEWATER...WINNETT AND ZORTMAN.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 7:53 PM MDTSevere Thunderstorm WarningGGWGarfield67 min
Jul 17, 8:52 PM MDTSevere Thunderstorm WarningGGWRichland53 min
Jul 17, 8:58 PM MDTSevere Thunderstorm WarningGGWGarfield, McCone, Prairie62 min
Jul 17, 9:51 PM MDTSevere Thunderstorm WarningGGWRichland54 min
Jul 17, 9:57 PM MDTSevere Thunderstorm WarningGGWDawson, McCone, Prairie63 min
Jul 17, 10:11 PM MDTTornado WarningGGWDawson64 min
Jul 17, 10:24 PM MDTSevere Thunderstorm WarningGGWRoosevelt, Sheridan66 min
Jul 17, 10:40 PM MDTFlash Flood WarningGGWRichland3 hr
Jul 17, 10:47 PM MDTSevere Thunderstorm WarningGGWRichland58 min
Jul 17, 10:52 PM MDTTornado WarningGGWRichland53 min
Jul 17, 10:54 PM MDTFlash Flood WarningGGWDawson3 hr
Jul 17, 10:56 PM MDTSevere Thunderstorm WarningGGWPrairie64 min
Jul 17, 11:09 PM MDTFlash Flood WarningGGWRoosevelt3 hr
Jul 17, 11:15 PM MDTSevere Thunderstorm WarningGGWDawson60 min
Jul 17, 11:23 PM MDTFlash Flood WarningGGWSheridan3 hr
Jul 17, 11:34 PM MDTSevere Thunderstorm WarningGGWRoosevelt, Sheridan56 min
Jul 17, 11:46 PM MDTSevere Thunderstorm WarningGGWRichland59 min
Jul 17, 11:51 PM MDTSevere Thunderstorm WarningGGWPrairie54 min
Jul 18, 12:47 AM MDTSevere Thunderstorm WarningGGWPrairie58 min
Jul 18, 1:07 AM MDTFlash Flood WarningGGWPrairie3 hr
Jul 18, 1:46 AM MDTFlash Flood WarningGGWRichland3 hr
Jul 18, 2:01 AM MDTFlash Flood WarningGGWDawson3 hr
Jul 18, 2:15 AM MDTFlash Flood WarningGGWRoosevelt3 hr
Jul 18, 2:28 AM MDTFlash Flood WarningGGWSheridan3 hr
Jul 18, 4:41 AM MDTFlash Flood WarningGGWDawson, McCone, Richland3 hr

Nearby

Tornado Warnings in Montana, 2001Every tornado warning in 2001Tornadoes 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.