June 3, 1981 appeared to be a pretty typical late spring day in the Denver metro area.  Afternoon thunderstorms though would become a ‘perfect storm’ and soon the city of Thornton would find itself witness to a tornado that would go down in the Denver weather history books.

Five tornadoes would strike that day but one would become the most infamous.  The Thornton tornado would tear through what was then the heart of the city damaging homes and businesses and sending many residents to the hospital.

The twister initially touched down at 2:43 p.m. and ripped across 2 miles of the city.  The tornado was rated an F2 on the Fujita Scale packing winds up to 157mph.

Following is a description of the event from the National Weather Service and below that is a slideshow of some photos of the event we have accumulated.

In 1981…severe thunderstorms produced tornadoes over metro Denver.  The first tornado touched down at the intersection of Alameda Ave. And Sheridan Blvd.  The twister moved north along Sheridan Blvd….damaging businesses…apartment buildings…homes…and vehicles.  Over ten homes were unroofed.  The roof of one landed in the middle of a neighborhood park.  At least 10 mobile homes were wrecked.

The tornado curved to the northeast into northwest Denver… Hopping up and down in several places.  Very strong winds outside the actual funnel caused 20 to 30 thousand dollars in damage in downtown Denver.  The third floor of one old building was demolished.  No major injuries were reported from the tornado…although several people were hurt slightly in traffic accidents on Sheridan Blvd. in the confusion caused by the storm.  Damage in Lakewood alone was estimated at 200 thousand dollars. 

At the same time… The worst tornado to ever hit metro Denver struck Thornton. Coming from the same thunderstorm that spawned the Denver twister…the Thornton tornado tore a swath through the heart of the city.  87 homes were destroyed…110 others damaged at least moderately.  In all…600 homes in a 100 block area sustained some damage.  The twister also hit shopping centers…several restaurants…and other buildings. Seven of the 42 injured were considered serious.  The storm was strong enough to snap lamp posts in half and drive a 6- inch slab of wood 2 feet into the ground.  Damage was estimated at up to 50 million dollars. 

The same storm that struck Thornton produced another damaging tornado that touched down in the northwest section of Fort Lupton.  This twister damaged 16 homes and numerous cars and campers. Two children were slightly injured when the car they were in was knocked about and its windows shattered by the storm.  The twister also damaged two commercial buildings.  Damage was very spotty…and observers said the storm hopped up and down at least 3 times.  Dollar damage was estimated at 500 thousand dollars. 

The thunderstorm complex that produced 3 damaging tornadoes also dropped large hail which damaged many cars over northwest Denver.  One to 2 inches of rain fell in less than an hour…flooding a mobile home park with 3 to 4 feet of water on the northwest edge of Denver.  The high water damaged about half of the 392 homes in the park.  Local flooding was also reported in other areas across metro Denver.  A tornado was also sighted near Franktown…but caused no damage.  A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

Also see:

• New York Times, June 4, 1981: At Least 40 in Denver Area Are Injured by Tornadoes
• Northglenn-Thornton Sentinel – June 26, 2008 – Off the top
• American Meteorological Society: A Subsynoptic Analysis of the Denver Tornadoes of 3 June 1981
• NCAR: June 26, 1981 press release about the Thornton tornado