Alert archive / Montana / Tornado Warnings in 1991
Tornado Warning 4, NWS Great Falls, MT
NWS Great Falls, MT issued this tornado warning at Jun 25, 1991, 4:01 PM MDT for Cascade County, Chouteau County, Montana. It was in force for 59 min.
The area
The counties it named.
The facts
- Issued
- Jun 25, 1991, 4:01 PM MDT (22:01 UTC)
- Expired
- Jun 25, 1991, 5:00 PM MDT
- In force
- 59 min
- Issued by
- NWS Great Falls, MT
- Area
- Whole counties
Counties Cascade County, MT, Chouteau County, MT
The nearest sounding before it
Great Falls, MT (KGTF), launched 12:00Z, 10.0 hours before the alert went out and 33 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.
- Mixed-layer CAPE
- 25 J/kg
- Mixed-layer CIN
- -33 J/kg
- Mixed-layer LCL
- 832 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- 67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KGTF 252203 TORGTF MTC013-015-252300- BULLETIN - EBS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 401 PM MDT TUE JUN 25 1991 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A TORNADO WARNING EFFECTIVE UNTIL 500 PM MDT FOR PEOPLE IN THE FOLLOWING LOCATION...S... IN NORTH CENTRAL MONTANA ...CASCADE COUNTY...WESTERN CHOUTEAU COUNTY THIS WARNING SUPERCEDES AND EXPANDS THE PREVIOUS SEVERE THUNDERSTORMS WARNING. THUNDERSTORMS...WITH HEAVY RAIN...HAIL...AND STRONG WINDS HAVE BEEN OBSERVED NEAR THE TOWN OF CASCADE. FUNNEL CLOUDS...AND TORNADOES ARE POSSIBLE WITH THESE STROMS. RADAR AND SATELLITE REPORTS INDICATE STRONG THUNDERSTORMS DEVELOPING SOUTHWEST OF GREAT FALLS MOVING NORTHEAST AT ABOUT 25 MPH. WHEN THUNDERSTORMS...TORNADOES...OR FUNNEL CLOUDS ARE OCCURRING...PEOP SHOULD MOVE INSIDE A STRONG BUILDING. DO NOT STAND BY WINDOWS. DON'T USE TELEPHONES OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSS
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 25, 12:55 PM MDT, 3 hours 6 minutes before
MTZ004-252000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE HELENA MT 1256 PM MDT TUE JUN 25 1991 THUNDERSTORMS ARE BEGINNING TO DEVELOP IN SOUTHWESTERN MONTANA THIS AFTERNOON. THUNDER IS BEING HEARD IN BUTTE FROM A STORM THAT IS TO THE WEST OF THE CITY. THIS STORM IS MOVING NORTHEAST AT 12 MILES AN HOUR. MISSOULA RADAR CLASSIFIES THIS STORM AS STRONG. LIGHTNING DETECTION CHARTS SHOW THIS STORM PRODUCING ABOUT 20 STRIKES IN THE PAST HALF HOUR. OTHER THUNDERSTORMS ARE GROWING IN THE VICINITY OF HELENA. THUNDERSTORMS WILL CONTINUE TO DEVELOP AS THE AFTERNOON GOES ON. IT IS POSSIBLE THAT THEY COULD PRODUCE HEAVY RAIN...HAIL...AND LIGHTNING. TRAVELERS AND PEOPLE INVOLVED IN OUTDOOR INTERESTS SHOULD MONITOR NOAA WEATHER RADIO AND OTHER MEDIA TO KEEP UPDATED ON THE WEATHER.
Special weather statement, Jun 25, 2:09 PM MDT, 1 hour 52 minutes before
MTZ004-252115- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE HELENA MT 211 PM MDT TUE JUN 25 1991 THUNDERSTORMS HAVE REACHED THE HELENA VALLEY. THEY ARE PRODUCING LIGHT SHOWERS AT THE HELENA AIRPORT AND SOUTH WINDS TO 23 MPH. THERE HAVE BEEN SOME LIGHTNING STRIKES BUT NOT MANY. THESE THUNDERSTORMS ARE MOVING TO THE NORTHEAST AT 12 MPH. OTHER SCATTERED THUNDERSTORMS CONTINUE IN SOUTHWEST MONTANA BUT RADAR SHOWS THEM BEING OF LIGHT INTENSITY.
Special weather statement, Jun 25, 3:10 PM MDT, 51 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 3:05 PM MDT TUE JUN 25 1991 A WEATHER OBSERVER AT SUN RIVER REPORTED 1/2 INCH SIZE HAIL SHORTLY AFTER 3 PM MDT. THE THUNDERSTORM WAS ALSO PRODUCING HEAVY RAINS. THE OBSERVER COMMENTED THAT THE STORM APPEARED TO BE INTENSIFYING. THE SUN RIVER IS LOCATED ABOUT 10 MILE NORTH AND WEST OF GREAT FALLS. THIS THUNDERSTORM IS MOVING NORTHEAST. LIGTNING DETECTION CHARTS VARIFY CLOUD TO GROUND CONTACT WITH THIS STORM. IF YOU SEE ANY THUNDERSTORM APPROACHING, STAY INDOORS AND ALERT. THIS IS NOT EXPECTED TO BECOME A SEVERE STORM AT THIS TIME. WRC/END
The office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 11:16 AM MDT | Tornado Warning | TFX | Cascade, Chouteau | 29 min |
| Jun 25, 3:31 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Chouteau | 59 min |
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.