Alert archive / Montana / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 55, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Jul 17, 2001, 3:22 PM MDT for Cascade County, Judith Basin County, Montana. It was in force for 38 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 17, 2001, 3:22 PM MDT (21:22 UTC)
- Expired
- Jul 17, 2001, 4:00 PM MDT
- In force
- 38 min
- Issued by
- NWS Great Falls, MT
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Cascade County, MT, Judith Basin County, MT
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 17, 3:55 PM MDT | Thunderstorm Wind 51 M | Geyser, MT | Reported by Air Force personnel assigned to missile site affiliated with Malmstrom AFB. |
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, 9.4 hours before the alert went out and 24 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
- 1066 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- -9 m²/s²
- 0-3 km storm-relative helicity
- -67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS55 KTFX 172123 SVRGTF MTC013-045-172200- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 322 PM MDT TUE JUL 17 2001 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EAST CENTRAL CASCADE COUNTY IN CENTRAL MONTANA NORTHWESTERN JUDITH BASIN COUNTY IN CENTRAL MONTANA * UNTIL 400 PM MDT * AT 315 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 15 MILES SOUTHWEST OF GEYSER...OR ABOUT 25 MILES WEST OF STANFORD...MOVING NORTHEAST AT 45 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... GEYSER AT 335 PM MDT REPORT SEVERE WEATHER TO THE NEAREST LAW EN*FORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS. LAT...LON 4720 11092 4707 11074 4737 11021 4741 11056
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 17, 3:00 PM MDT, 22 minutes earlier.
Area forecast discussion, Jul 17, 3:00 PM MDT, 22 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 300 PM MDT TUE JUL 17 2001 GENERAL PATTERN CONTINUES OF LOW PRESSURE CENTER OVER SOUTHERN BC/ALTA WITH TROF EXTENDING SOUTH OVER PACIFIC NORTHWEST. AIRMASS IS UNSTABLE CENTRAL THROUGH SOUTHERN CWA. WEAK SHORTWAVE IS AGAIN MOVING THROUGH SOUTHWEST FLOW ALOFT...AND ANOTHER AREA OF DIFLUENCE ALOFT OVER SOUTHWEST AND CENTRAL MT. RELATIVELY LOW CONVECTIVE TEMPERATURES THIS AFTERNOON ACROSS THE CWA AND SW MT IS ALREADY SHOWING CONVECTION...SO SOMEWHAT WET FORECAST FOR THIS EVENING. AIRMASS DRIES SLIGHTLY BY WEDNESDAY ALTHOUGH ATMOSPHERE REMAINS UNSTABLE OVER SOUTHERN CWA...AND NORTHERN CWA NEUTRAL TO STABLE. WILL CONTINUE WITH ISOLATED POPS OVER MOST AREAS THRU THURSDAY FOR AFTERNOON CONVECTION. ZELZER EXTENDED... UPPER LEVEL TROUGH OVER PACIFIC NW CONTINUES TO BRING A MOIST AND UNSTABLE SOUTHWEST FLOW ALOFT OVER AREA DAYS 3 AND 4. BY DAY 5... MODELS DO DIFFER IN DETAILS OF TROUGH PACIFIC NW. MRF/ECMWF BRINGS IN WEAK UPPER RIDGE OVER AREA. WHILE NEW AVN SWINGS SHORT WAVE ACROSS AREA. BY DAY 6...ECMWF HAS HIGHER AMPLITUDE RIDGE OVER ERN MONTANA. OVERALL...IT WILL BE COOL AND UNSETTLED AT FIRST WITH WARMER CONDITIONS AND PRECIP DECREASING TO ISOLATED DURING THE LAST HALF OF PERIOD. WILLIAMSON DC CCF NUMBERS GTF BB 049/079 050/080 051 13311 CTB BB 045/075 046/075 048 13211 HLN EB 049/078 049/080 05 0 13522 BZN EE 048/076 048/078 048 13622 WEY EE 042/072 042/074 042 13622 DLN EB 045/074 045/076 048 13321 HVR BB 056/085 056/088 056 13311 LWT EB 050/076 048/078 052 13522
The office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 16, 6:33 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 42 min |
| Jul 16, 7:17 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 28 min |
| Jul 17, 4:15 PM MDT | Severe Thunderstorm Warning | TFX | Fergus, Judith Basin | 45 min |
| Jul 17, 4:58 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 27 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.