Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 101, NWS Glasgow, MT

July 20, 2001Daniels County, Roosevelt County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 20, 2001, 12:53 PM MDT for Daniels County, Roosevelt County, Montana. It was in force for 52 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 20, 2001, 12:53 PM MDT (18:53 UTC)
Expired
Jul 20, 2001, 1:45 PM MDT
In force
52 min
Issued by
NWS Glasgow, MT
Area
Whole counties

Counties Daniels County, MT, Roosevelt County, MT

The radar

The Glasgow radar (KGGW), 106 km from the middle of the area, began a volume at 19:14 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

TimeReportWhereRemark
Jul 20, 1:00 PM MDTHail 0.75Peerless, MT

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.

IssuedProductOfficeLasted
Jul 20, 12:30 PM MDTTornado WatchSPC6 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 6.9 hours before the alert went out and 104 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 12:00Z on 2001-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 28 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 12:00Z on 2001-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
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 
WUUS55 KGGW 201853
SVRGGW

MTC019-085-201945-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GLASGOW MT
1253 PM MDT FRI JUL 20 2001

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  DANIELS COUNTY IN NORTHEAST MONTANA
  WESTERN ROOSEVELT COUNTY IN NORTHEAST MONTANA

* UNTIL 145 PM MDT

* AT 1250 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 16 MILES SOUTH OF PEERLESS...OR ABOUT 25 MILES
  SOUTHWEST OF SCOBEY...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SCOBEY BY 130 PM MDT
  MADOC BY 140 PM MDT

LARGE HAIL...DAMAGING WINDS...AND HEAVY RAINFALL ARE LIKELY WITH THIS
STORM. TAKE COVER IN A STURDY BUILDING UNTIL THE STORM HAS PASSED.

A TORNADO WATCH IS ALSO IN EFFECT. SEVERE THUNDERSTORMS CAN PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING. PREPARE TO MOVE TO A
PLACE OF SAFETY IN A STURDY STRUCTURE SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM IF A TORNADO IS SPOTTED.

.END

79

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 20, 9:00 AM MDT, 3 hours 53 minutes earlier.

Area forecast discussion, Jul 20, 9:00 AM MDT, 3 hours 53 minutes before
NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
900 AM MDT FRI JUL 20 2001

...NO CHANGES TO CURRENT FORECAST...

STORMS ARE STARTING EARLY AGAIN TODAY AGAIN WITH SEVERE WEATHER
PARAMETERS IN PLACE AS WELL. NEW ETA 500MB VORT PATTERN INDICATING THIS
FIRST ROUND WILL GO THROUGH HERE OVER THE NEXT 2 TO 4 HOURS...WITH MAYBE
A RE-FIRE LATER IN THE AFTERNOON/EVENING. SPC/S MODERATE RISK LOOKS
GOOD. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED IN ANTICIPATION
OF THE VOLATILE CONDITIONS EXPECTED FOR TODAY. JAMBA

EXTENDED...MID RANGE MODELS SUGGESTING SLIGHT SHIFT IN PATTERN WITH
BASE OF PACIFIC TROF CUTTING OFF AND FLOW ACROSS NORTHERN TIER OF
STATE BECOMING MORE ZONAL UNDER OMEGA BLOCK OVER CANADA. WITH FLOW
TURNING WEST SHOULD CUT OFF MOISTURE FEED OVER THE MOUNTAINS FOR
DRIER PATTERN FOR EASTERN MONTANA BY MID WEEK. ONLY CHANGE TO
EXTENDED WILL BE TO ADD SATURDAY NIGHT PERIOD TO EMPHASIZE CHANGE OF
THUNDERSTORMS THAT NIGHT. EBERT

KGGW /083 062/088 064/085 057/082 058/083 058/083 058/084
      TTTTTBT  90543/9033323
KGDV /085 065/089 064/085 060/084 060/084 060/084 057/085
      TTTTTBT  90543/9033323

In the hours before

Special weather statement, Jul 20, 8:40 AM MDT, 4 hours 13 minutes before
MTZ016>027-059>062-202200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
840 AM MDT FRI JUL 20 2001

...A GOOD CHANCE OF SEVERE WEATHER ACROSS NORTHEAST MONTANA TODAY...

A MOIST...UNSTABLE AIRMASS IN PLACE ACROSS NORTHEAST MONTANA COMBINED
WITH AN UPPER LEVEL DISTURBANCE PUSHING ACROSS THE AREA TODAY WILL
BRING THUNDERSTORMS...SOME OF THEM SEVERE. ANY SEVERE THUNDERSTORM
WILL BRING LARGE HAIL...DAMAGING WINDS AND TORRENTIAL RAIN. THE
SEVERE THUNDERSTORM POTENTIAL STARTED THIS MORNING AND WILL LIKELY
LAST INTO THE EVENING HOURS TONIGHT.

ANYONE WITH OUTDOOR ACTIVITIES PLANNED TODAY SHOULD LISTEN TO NOAA
WEATHER RADIO...OR ANOTHER MEDIA OUTLET...TO KEEP POST ED ON ANY WATCHES
OR WARNINGS THAT MAY BE ISSUED TODAY.

THIS INFORMATION CAN ALSO BE OBTAINED FROM OUR WEB SITE AT:
HTTP://WWW.WRH.NOAA.GOV/GLASGOW

TFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 7:38 PM MDTTornado WarningGGWWibaux67 min
Jul 20, 9:22 AM MDTSevere Thunderstorm WarningGGWPhillips53 min
Jul 20, 11:47 AM MDTSevere Thunderstorm WarningGGWPhillips58 min
Jul 20, 12:14 PM MDTSevere Thunderstorm WarningGGWValley61 min
Jul 20, 1:14 PM MDTSevere Thunderstorm WarningGGWSheridan61 min
Jul 20, 1:15 PM MDTSevere Thunderstorm WarningGGWValley60 min
Jul 20, 2:49 PM MDTTornado WarningGGWPhillips56 min
Jul 20, 3:25 PM MDTTornado WarningGGWValley65 min
Jul 20, 3:45 PM MDTTornado WarningGGWPhillips45 min
Jul 20, 4:30 PM MDTTornado WarningGGWGarfield, Valley60 min
Jul 20, 5:16 PM MDTTornado WarningGGWMcCone59 min
Jul 20, 5:27 PM MDTTornado WarningGGWDaniels63 min
Jul 20, 5:30 PM MDTTornado WarningGGWGarfield60 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001Every 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; radar from the NEXRAD Level II archive.