Alert archive / Montana / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 2, NWS Great Falls, MT

June 15, 1987Cascade County, Teton County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 15, 1987, 5:20 PM MDT for Cascade County, Teton County, Montana. It was in force for 100 min.

The area

The counties it named.

The facts

Issued
Jun 15, 1987, 5:20 PM MDT (23:20 UTC)
Expired
Jun 15, 1987, 7:00 PM MDT
In force
100 min
Issued by
NWS Great Falls, MT
Area
Whole counties

Counties Cascade County, MT, Teton 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 (KGTF), launched 12:00Z, 11.3 hours before the alert went out and 38 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 1987-06-15Temperature 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 1987-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.193958Sfc1 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
3179 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
46 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 152319
SVRGTF
MTC013-099-160115-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
520 PM MDT MON JUN 15 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  700 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN MONTANA EAST OF THE DIVIDE
          ...CASCADE...TETON
 
ANOTHER LINE OF POSSIBLE SEVERE THUNDERSTORMS WILL MOVE  INTO CASCADE
AND TETON COUNTIES BEFORE 6 PM MDT AND LAST ABOUT AN HOUR.  WIND
GUSTS IN EXCESS OF 50 MPH ALONG WITH  BRIEF HEAVY RAIN AND HAIL MAY
ACCOMPANY  THIS NEW SURGE OF THUNDERSTORMS.
 
PERSONS IN CASCADE AND TETON COUNTIES SHOULD BE PREPARED FOR THE
STRONG WINDS...LIGHTNING AND HAIL UNTIL ABOUT 7PM MDT.

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

Special weather statement, Jun 15, 2:24 PM MDT, 2 hours 56 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS, MT
218 PM MDT MON JUN 15 1987

...STRONG THUNDERSTORMS FORMING IN EASTERN MONTANA THIS AFTERNOON...

THUNDERSTORMS WITH GUSTY WINDS IN EXCESS OF 50 MPH HAVE BEEN
REPORTED IN PORTIONS OF SOUTHWEST MONTANA EARLY THIS AFTERNOON.

THESE THUNDERSTORMS ARE MOVING OUT INTO THE PLAINS OF EASTERN
MONTANA AND WILL CAUSE LOCAL STRONG GUSTY WINDS AND POSSIBLE HAIL
THIS AFTERNOON AND EVENING.

CAUSE OF THESE THUNDERSTORMS ARE A COMBINATION OF INCREASING MOIST
SOUTHERLY FLOW AND UNUSUALLY HOT TEMPERATURES OVER THE STATE.
AS THE MOIST FLOW INCREASES LATER THIS AFTERNOON AND TONIGHT
MORE THUNDERSTORMS WILL  FORM OVER THE STATE WITH THE PROSPEC)T
OF GUSTY WINDS...RAIN AND POSSIBLE HAIL.

OLSEN
Special weather statement, Jun 15, 3:51 PM MDT, 1 hour 29 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HAVRE MT
345 PM MDT MON JUN 15 1987

...STRONG THUNDERSTROMS IN CENTRAL AND SOUTHWESTERN MONTANA...

THE NATIONAL SEVERE STORMS FORECAST CENTER IN KANSAS CITY HAS ISSUED
A SEVERE THUNDERSTORM WATCH FOR SOUTHWESTERN MONTANA UNTIL 10:00PM
MDT THIS EVENING.

THUNDERSTORMS WITH HAIL AND STRONG GUSTY WINDS HAVE ALREADY OCCURRED
IN THIS AREA.  EARLIER DILLON REPORTED WIND GUSTS TO 55 MPH WITH
UNCONFIRMED REPORTS OF 3/4" HAIL.  LIVINGSTON HAD WINDS GUSTS TO 61
MPH AS A THUNDERSTORM PASSED THROUGH AND AT 3:30PM MDT THIS AFTERNOON
GREAT FALLS REPORTED MODERATE RAIN SHOWERS AND WIND GUSTING TO 45
MPH.

THESE THUNDERSTORMS ARE MOVING NORTHWARD AND SHOULD BE IN NORTH-
CENTRAL MONTANA WITHIN THE NEXT FEW HOURS.  NORTH-CENTRAL MONTANA
,CAN EXPECT BRIEF HEAVY RAIN AND STRONG GUSTY WINDS WITH A FEW OF
THESE STORM CELLS.
/CORP/

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 15, 3:46 PM MDTSevere Thunderstorm WarningTFXFergus59 min

Nearby

Severe Thunderstorm Warnings in Montana, 1987Every severe thunderstorm warning in 1987

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.