Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 97, NWS Great Falls, MT

September 18, 1998Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Sep 18, 1998, 2:32 PM MDT for Gallatin County, Montana. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 18, 1998, 2:32 PM MDT (20:32 UTC)
Expired
Sep 18, 1998, 3:05 PM MDT
In force
33 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Gallatin County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.5 hours before the alert went out and 218 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, Great_falls, MT at 12:00Z on 1998-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Great_falls, MT at 12:00Z on 1998-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
859 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

846 
WUUS1 KGTF 182033 RRA
SVRGTF
MTC031-182105-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
232 PM MDT FRI SEP 18 1998


THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GALLATIN COUNTY IN SOUTHWESTERN MONTANA

* UNTIL 305 PM MDT

* AT 223 PM MDT... DOPPLER RADAR AT GREAT FALLS INDICATED A SEVERE
  THUNDERSTORM IN THE VICINITY OF BOZEMAN OR IN THE VICINITY OF
  BELGRADE MOVING NORTHEAST AT 40 MPH.

* SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM ARE...
  BELGRADE AND   BOZEMAN.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 2:49 PM MDTSevere Thunderstorm WarningTFXJudith Basin51 min
Sep 18, 3:35 PM MDTSevere Thunderstorm WarningTFXChouteau, Teton50 min
Sep 18, 4:37 PM MDTSevere Thunderstorm WarningTFXChouteau, Liberty38 min

Nearby

Severe Thunderstorm Warnings in Montana, 1998Every severe thunderstorm warning in 1998

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.