Alert archive / Montana / Tornado Warnings in 1986

Tornado Warning 3, NWS Great Falls, MT

June 29, 1986Chouteau County, Montana

NWS Great Falls, MT issued this tornado warning at Jun 29, 1986, 1:16 PM MDT for Chouteau County, Montana. It was in force for 74 min.

The area

The counties it named.

The facts

Issued
Jun 29, 1986, 1:16 PM MDT (19:16 UTC)
Expired
Jun 29, 1986, 2:30 PM MDT
In force
74 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Chouteau County, MT

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 7.3 hours before the alert went out and 48 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 1986-06-29Temperature 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 1986-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939587897Sfc1 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
3619 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
39 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.

000 
TTAA00 KGTF 291916
TORGTF
MTC015-292030-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
116 PM MDT SUN JUN 29 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 230 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

NORTH CENTRAL MONTANA...CHOTEAU AND THE CITY OF FORT BENTON

AT 1PM MDT RADAR INDICATED A TORNADO 30 MILES NORTH OF
GREAT FALLS. THIS TORNADIC STORM WAS MOVING TO THE EAST
AT 35 MILES AN HOUR. PERSONS IN CHOUTEAU COUNTY INCLUDING
THE TOWN OF FORT BENTON SHOULD TAKE COVER SHOULD THREATENING
WEATHER APPROACH.

What forecasters said that day

The local office's own words before this tornado 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, Jun 29, 8:54 AM MDT, 4 hours 22 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS, MT
854 AM MDT SUN JUN 29 1986

TIME              EVENT

2 AM MDT          A CO-OP OBSERVER LOCATED 23 MILES EAST OF JORDAN
                  MONTANA REPORTED A THUNDERSTORM WITH HEAVY RAIN
                  AND LARGE HAIL OCCURRED BETWEEN 12 AND 2 AM MDT.
                  TOTAL RAINFALL WAS 3.25 INCHES. HAIL FOUND THIS
                  MORNING MEASURED UP TO 1.5" IN DIAMETER...AND WAS
                  DRIFTED 6 TO 8 FEET HIGH. HAIL DENTED CARS AND
                  STRIPPED LEAVES FROM TREES. THE HEAVY RAIN WASHED
                  OUT SEVERAL ROADS.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 11:51 AM MDTTornado WarningTFXPondera69 min

Nearby

Tornado Warnings in Montana, 1986Every tornado warning in 1986Tornadoes in 1986

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.