Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 69, NWS Great Falls, MT

July 11, 1998Madison County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 11, 1998, 2:29 PM MDT for Madison County, Montana. It was in force for 61 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: Jul 11, 1998, 2:29 PM MDT (20:29 UTC)
Expired: Jul 11, 1998, 3:30 PM MDT
In force: 61 min
Issued by: NWS Great Falls, MT
Area: Whole counties

County Madison County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.5 hours before the alert went out and 261 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 32 J/kg
Mixed-layer CIN: -306 J/kg
Mixed-layer LCL: 1932 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 52 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.

387 
WUUS1 KGTF 112030 RRA
SVRGTF
MTC057-112130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
229 PM MDT SAT JUL 11 1998


THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN MADISON COUNTY IN SOUTHWESTERN MONTANA

* UNTIL 330 PM MDT

* AT 227 PM MDT... SPOTTERS REPORTED A SEVERE THUNDERSTORM IN THE
  VICINITY OF VIRGINIA CITY MOVING NORTHEAST AT 30 MPH. SPOTTERS IN
  VIRGINIA CITY REPORTED 1 3/4 INCH HAIL AS THE STORM PASSED OVER
  THE CITY.

* SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM ARE...
  ENNIS...   JEFFERS AND   MCALLISTER.



&

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.

In the hours before

Local storm report, Jul 11, 11:44 AM MDT, 2 hours 45 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS, MT
1144 AM MDT SAT JUL 11 1998

TIME(MDT)  ......CITY LOCATION...... MT   ...EVENT.............
DATE(MDT)  ......COUNTY LOCATION....      ...REMARKS...........

0540 PM    4S GREAT FALLS            MT   WINDS GUST TO EST 65 MPH
07/10/98   CASCADE                        DESTROYED GARAGE.

0545 PM    GREAT FALLS               MT   HAIL 0.63 TO 0.75 INCH HAIL
07/10/98   CASCADE                        *.56 RAIN SHORT PERIOD OF TIME

0745PM     VALENTINE                 MT   WINDS BLEW OLD BUILDING AND
           FERGUS                         GARAGE DOWN.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 6:25 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	35 min
Jul 10, 7:29 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	36 min
Jul 11, 3:30 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	65 min
Jul 11, 5:43 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	47 min

Nearby

Severe Thunderstorm Warnings in Montana, 1998 Every 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.