Alert archive / Montana / Tornado Warnings in 1991

Tornado Warning 13, NWS Billings, MT

June 21, 1991Big Horn County, Montana

NWS Billings, MT issued this tornado warning at Jun 21, 1991, 6:22 PM MDT for Big Horn County, Montana. It was in force for 68 min.

The area

The counties it named.

The facts

Issued
Jun 21, 1991, 6:22 PM MDT (00:22 UTC)
Expired
Jun 21, 1991, 7:30 PM MDT
In force
68 min
Issued by
NWS Billings, MT
Area
Whole counties

County Big Horn County, MT

The nearest sounding before it

Lander/Hunt Fiel, WY (KLND), launched 00:00Z, 0.4 hours before the alert went out and 305 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, Lander/Hunt Fiel, WY at 00:00Z on 1991-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 759 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lander/Hunt Fiel, WY at 00:00Z on 1991-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 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
759 J/kg
Mixed-layer CIN
-141 J/kg
Mixed-layer LCL
2029 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBIL 220022
TORBIL
MTC003-220130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE BILLINGS MT
622 PM MDT FRI JUN 21 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 730 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE STATE OF MONTANA
      NORTHERN BIG HORN

AT 615PM MDT THE BIG HORN COUNTY SHERIFF REPORTED A FUNNEL CLOUD
AT CROW AGENCY MONTANA. WEATHER RADAR SHOWS THE THUNDERSTORMS
IN THIS AREA TO BE MOVING NORTHEAST AT 25 MPH.

DO NOT USE YOUR CAR TO TRY TO OUTRUN A TORNADO.  CARS ARE EASILY
TOSSED AROUND BY TORNADO WINDS.  IF YOU ARE CAUGHT IN THE PATH OF
A TORNADO...LEAVE THE CAR AND GO TO A STRONG BUILDING.  IF NO
STRUCTURE IS NEARBY...TAKE SHELTER IN A DITCH OR LOW SPOT.

 STAY ALERT.  IF THREATENING WEATHER IS SIGHTED GO TO A SAFE PLACE
 IMMEDIATELY.  WHEN IT IS SAFE PLEASE RELAY YOUR REPORT OF SEVERE
 WEATHER TO THE NEAREST LAW ENFORCvEMENT AGENCY.

 END/FORBES

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

Special weather statement, Jun 21, 1:48 PM MDT, 4 hours 34 minutes before
WYZ003-004-005-212300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHERIDAN WY
150 PM MDT WED JUN 21 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR SHERIDAN AND JONHSON
COUNTIES UNTIL 8 PM MDT THIS EVENING...

AT 130 PM MDT RADAR SHOWED THUNDERSTORMS STARTING TO DEVELOP IN
NORTH CENTRAL WYOMING.  AT THIS TIME NO SEVERE WEATHER HAS BEEN
REPORTED.  THE STRONGEST OF THESE STORMS IS SOUTH OF SHERIDAN ABOUT
25 MILES MOVING NORTHEAST.

,PERSONS IN NORTH CENRAL WYOMING SHOULD KEEP AN EYE ON THE WEATHER
AND IF THREATENING WEATHER IS SIGHT GO TO A SAFE PLACE.

ZEGLIN
Special weather statement, Jun 21, 4:47 PM MDT, 1 hour 35 minutes before
WYZ003-004-005-220200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHERIDAN WY
450 PM MDT WED JUN 21 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR SHERIDAN AND JONHSON
COUNTIES UNTIL 8 PM MDT THIS EVENING...

AT 430 PM MDT RADAR SHOWED SOME WIDELY SCATTERED THUNDERSTORMS
IN NORTH CENTRAL WYOMING. AT THIS TIME NO SEVERE WEATHER HAS BEEN
REPORTED IN THE AREA. THESE THUNDERSTORMS ARE MOVING NORTHEAST
A ABOUT 25 MILES AN HOUR.

PERSO5NS IN NORTH CENRAL WYOMING SHOULD KEEP AN EYE ON THE WEATHER
AND IF THREATENING WEATHER IS SIGHTED GO TO A SAFE PLACE.

ZEGLIN
Special weather statement, Jun 21, 4:49 PM MDT, 1 hour 33 minutes before
WYZ003-004-005-220200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHERIDAN WY
450 PM MDT FRI JUN 21 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR SHERIDAN AND JONHSON
COUNTIES UNTIL 8 PM MDT THIS EVENING...

AT 430 PM MDT RADAR SHOWED SOME WIDELY SCATTERED THUNDERSTORMS
IN NORTH CENTRAL WYOMING. AT THIS TIME NO SEVERE WEATHER HAS BEEN
REPORTED IN THE AREA. THESE THUNDERSTORMS ARE MOVING NORTHEAST
A ABOUT 25 MILES AN HOUR.

PERSO6NS IN NORTH CENRAL WYOMING SHOULD KEEP AN EYE ON THE WEATHER
AND IF THREATENING WEATHER IS SIGHTED GO TO A SAFE PLACE.

ZEGLIN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 6:21 PM MDTFlash Flood WarningBYZMusselshell3 hr
Jun 21, 6:56 PM MDTFlash Flood WarningBYZBig Horn, Treasure3 hr
Jun 21, 8:41 PM MDTTornado WarningBYZCuster, Rosebud64 min
Jun 21, 9:36 PM MDTFlash Flood WarningBYZMusselshell3 hr
Jun 21, 9:36 PM MDTFlash Flood WarningBYZBig Horn, Treasure3 hr
Jun 21, 11:36 PM MDTFlash Flood WarningBYZMusselshell6 hr
Jun 21, 11:36 PM MDTFlash Flood WarningBYZTreasure6 hr

Nearby

Tornado Warnings in Montana, 1991Every tornado warning in 1991Tornadoes in 1991

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.