Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 98, NWS Glasgow, MT

July 20, 2001Phillips County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 20, 2001, 9:22 AM MDT for Phillips County, Montana. It was in force for 53 min. 2 reports 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, 9:22 AM MDT (15:22 UTC)
Expired
Jul 20, 2001, 10:15 AM MDT
In force
53 min
Issued by
NWS Glasgow, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Phillips County, MT

What was reported inside it

TimeReportWhereRemark
Jul 20, 9:40 AM MDTHail 0.75Bowdoin, MT
Jul 20, 9:46 AM MDTHail 0.75Malta, 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 nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 3.4 hours before the alert went out and 97 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

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 20, 9:00 AM MDT, 22 minutes earlier.

Area forecast discussion, Jul 20, 9:00 AM MDT, 22 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, 42 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, 11:47 AM MDTSevere Thunderstorm WarningGGWPhillips58 min
Jul 20, 12:14 PM MDTSevere Thunderstorm WarningGGWValley61 min
Jul 20, 12:53 PM MDTSevere Thunderstorm WarningGGWDaniels, Roosevelt52 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.