Granite Falls Tornado: July 25, 2000

A destructive and deadly tornado struck the city of Granite Falls (Yellow Medicine County) on July 25, 2000. One person was killed, over a dozen injured, and millions of dollars of damage was done to residences, businesses, and public facilities. In the aftermath of the storm, the National Weather Service dispatched an assessment team to evaluate the force and the extent of the tornado. The following statement from the National Weather Service was released on July 27, 2000

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
430 PM CDT JUL 27 2000

...GRANITE FALLS TORNADO CLASSIFIED...
GRANITE FALLS, MINNESOTA WAS HIT BY A MAJOR TORNADO ON TUESDAY
EVENING JULY 25TH. NATIONAL WEATHER SERVICE OFFICIALS FROM
MINNEAPOLIS AND SIOUX FALLS SPENT THE FOLLOWING DAY ASSESSING
STORM DAMAGE AND DETERMINING THE TORNADO PATH AND ESTIMATED
INTENSITY. THE ASSESSMENT TEAM INCLUDED WARNING COORDINATION
METEOROLOGIST TODD HEITKAMP FROM SIOUX FALLS, METEOROLOGIST IN
CHARGE GREG HARMON FROM SIOUX FALLS, AND METEOROLOGIST IN CHARGE
CRAIG EDWARDS FROM MINNEAPOLIS.

THE TORNADO MOVED THROUGH GRANITE FALLS BETWEEN 610 PM AND 625 PM ON
JULY 25TH. IT WAS ON THE GROUND FOR APPROXIMATELY NINE MILES, FIRST
TOUCHING DOWN IN RURAL YELLOW MEDICINE COUNTY 8 MILES WEST AND 3
MILES NORTH OF GRANITE FALLS. THE TORNADO LIFTED BEFORE EXITING THE
COMMUNITY, LEAVING A CONCENTRATED DAMAGE PATH 2 MILES LONG AND 500
FEET WIDE THROUGH A PRIMARILY RESIDENTIAL AREA OF GRANITE FALLS.
MOST OF THE DAMAGE IN GRANITE FALLS WAS CAUSED BY F2 TO F3 WIND
SPEEDS. HOWEVER, THIS TORNADO WILL BE CLASSIFIED OFFICIALLY AS A
MINIMAL F4 TORNADO BASED ON THE ESTIMATED MAXIMUM WIND SPEED
INTENSITY NEAR THE INTERSECTION OF 9TH AVENUE AND 14TH STREET IN
GRANITE FALLS.


THE FUJITA SCALE (F-SCALE) IS THE DAMAGE CLASSIFICATION SYSTEM USED
BY THE NATIONAL WEATHER SERVICE TO RATE ALL TORNADOES. THE SCALE
RANGES FROM F0 FOR WEAK TORNADOES TO F5 FOR THE STRONGEST. THE
SCALE WAS DEVELOPED BY PROFESSOR EMERITUS THEODORE FUJITA AT THE
UNIVERSITY OF CHICAGO. THE FOLLOWING ARE THE WIND SPEEDS AND DAMAGE
PATTERNS ASSOCIATED WITH THE F-SCALE USED TO ASSESS THE GRANITE
FALLS TORNADO:

F2...113-157 MPH...CONSIDERABLE DAMAGE. ROOFS TORN OFF FRAME
HOUSES...MOBILE HOMES DEMOLISHED...LARGE TREES SNAPPED OR UPROOTED.
F3...158-206 MPH...SEVERE DAMAGE. ROOFS AND SOME WALLS TORN OFF
WELL-CONSTRUCTED BUILDINGS. MOST LARGE TREES STRIPPED AND UPROOTED.
HEAVY OBJECTS LIKE CARS STRIPPED AND THROWN A SHORT DISTANCE.

F4...207-260 MPH...DEVASTATING DAMAGE. WELL CONSTRUCTED HOMES
LEVELED. STRUCTURES WITH WEAK FOUNDATIONS BLOWN OFF SOME DISTANCE.
CARS AND OTHER VERY HEAVY OBJECTS LIFTED AND THROWN SOME DISTANCE.
THE LAST F4 TO AFFECT MINNESOTA OCCURRED ON MARCH 29, 1998 WHEN
COMFREY IN BROWN COUNTY EXPERIENCED SIMILAR TORNADO DAMAGE.

IF YOU HAVE QUESTIONS CONCERNING THE RATING OF THE GRANITE FALLS
TORNADO, PLEASE CONTACT CRAIG EDWARDS AT THE NATIONAL WEATHER
SERVICE OFFICE IN CHANHASSEN.


CRAIG EDWARDS
METEOROLOGIST IN CHARGE
For more information contact: climate@umn.edu