Alert archive / Montana / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 71, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Jul 23, 2001, 4:56 PM MDT for Meagher County, Montana. It was in force for 34 min. 1 report 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 23, 2001, 4:56 PM MDT (22:56 UTC)
- Expired
- Jul 23, 2001, 5:30 PM MDT
- In force
- 34 min
- Issued by
- NWS Great Falls, MT
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Meagher County, MT
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 23, 4:56 PM MDT | Hail 1 | Martinsdale, MT | Actual event location Martinsdale 10 N...Slight damage to automobiles (monetary amount of damage unknown). |
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
Great_falls, MT (KTFX), launched 12:00Z, 10.9 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1102 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- -61 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
668 WUUS55 KTFX 232256 SVRGTF MTC059-232330- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 456 PM MDT MON JUL 23 2001 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EXTREME EAST CENTRAL MEAGHER COUNTY IN CENTRAL MONTANA * UNTIL 530 PM MDT * AT 455 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 6 MILES NORTH OF MARTINSDALE...OR ABOUT 24 MILES WEST OF HARLOWTON...MOVING EAST AT 20 MPH. LARGE HAIL UP TO ONE INCH IN DIAMETER IS POSSIBLE WITH THIS STORM. REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS. LAT...LON 4662 11043 4642 11039 4642 11017 4665 11021 $$ BRUSDA
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 Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 23, 3:00 PM MDT, 1 hour 56 minutes earlier.
Area forecast discussion, Jul 23, 3:00 PM MDT, 1 hour 56 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 300 PM MDT MON JUL 23 2001 POSITIVELY TILTED UPPER TROUGH IS FORECAST BY THE MODELS TO EXTEND FROM NW MT TO ERN OREGON AT 00Z TUE. NRN PORTION OF THE UPPER TROUGH WILL WORK ITS WAY THROUGH THE NRN ZONES TONIGHT AND THROUGH THE SRN ZONES LATER TONIGHT AND EARLY TUE MORNING. TUE NIGHT A SHORTWAVE EMBEDDED IN A WLY FLOW ALOFT IS FORECAST BY THE MODELS TO SKIRT THE NRN ZONES. FOR WED WSW FLOW ALOFT IS OVER AREA. AN EVEN WEAKER SHORTWAVE MAY AFFECT THE NRN ZONES WHILE THE AVN HAS A SHORTWAVE AFFECTING THE FAR SRN ZONES. CHECK OF CROSS SECTIONS SHOWS A FAIRLY DRY AIRMASS AND WITH FLOW ALOFT GENERALLY WLY DO NOT SEE MUCH THREAT FOR PRECIPITATION AFTER TONIGHT. A SHORTWAVE OVER SW MT AT 18Z MON WL MOV INTO S CENTRAL MT LATER MON AFTERNOON. MODELS INDICATE A FAIRLY UNSTABLE AIRMASS OVER SW AND CENTRAL MT WITH CAPES ROUGHLY IN THE 500 JOULES/KG RANGE. WILL GO WITH 20 AND 30 PCT RANGE FOR THIS AREA. FOR TUE ETA/AVN HAVE A SURFACE CONVERGENCE AXIS OVER CENTRAL MT WITH LIFTED INDICES OF MINUS 2 AS FAR W AS NEAR HVR/LWT. WILL GO WITH A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS FOR BLAINE AND FERGUS COUNTIES. TO MAKE A MORE SEAMLESS FORECAST WITH BIL WILL MENTION A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR GALLATIN COUNTY. FOR WED ETA KEEPS THE THREAT OF THUNDERSTORMS EAST OF THE FORECAST AREA BUT AVN HAS MINUS 2 LIFTED INDEX ISOPLETH OVER FERGUS COUNTY WITH SURFACE CONVERGENCE AXIS FROM BZN TO GTF TO W OF HVR. CONSENSUS AMONGST THE FORECASTERS WAS TO GO WITH THE ETA SOLUTION SO WILL GO DRY. EXTENDED...CWA COMES UNDER THE INFLUENCE OF A WESTERLY FLOW ALOFT DURING THE FIRST PART OF THE EXTENDED FORECAST. CONTINUED CHANCE OF PRECIPITATION DAY 3...PRIMARILY OVER THE EASTERN PORTION OF THE CWA. BY DAY 4 FLOW ALOFT BACKS A BIT AS UPPER TROF BEGINS TO APPROACH THE WEST COAST. ENOUGH OF A DOWNSLOPE TO FEND OFF MOST PRECIPITATION.UPPER TROF SWINGS INLAND DAY 5 WITH INCREASING SOUTHWEST FLOW ALOFT. SURFACE GRADIENTS INDICATE MODERATE WEST WINDS WHICH SHOULD INHIBIT ANY PRECIPITATION NEAR THE MOUNTAINS. TROF WEAKENS AS IT PUSHES ALONG THE CANADIAN BORDER DAY 6 WITH CONTINUED MODERATE WESTERLY WINDS AT THE SURFACE. DAY 7 LOOKS DRY AND COOLER WITH A RETURN TO ZONAL FLOW ALOFT. CCF NUMBERS GTF BB 052/082 052/082 052 04211 CTB BB 048/078 048/078 048 04111 HLN BB 052/082 053/082 052 04311 BZN BB 049/082 049/082 048 04211 WEY BB 038/078 038/078 040 04221 DLN BB 047/079 047/079 047 04211 HVR BB 054/085 055/083 054 04111 LWT BB 050/080 050/080 050 04321
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.