Teton-Yellowstone tornado
The Teton–Yellowstone tornado was a rare high-altitude tornado which occurred on July 21, 1987, in the U.S. state of Wyoming. Rated at F4 on the Fujita scale, it remains the strongest tornado ever recorded in the state and the only officially rated F4/EF4 in Wyoming history. The tornado cut through a 24.4-mile (39.2 km)-long and 1.6-mile (2.5 km)-wide swath of the Teton Wilderness and Yellowstone National Park, crossing the Continental Divide. Damage occurred at elevations ranging from 8,500 to 10,000 feet (2,600 to 3,000 m), making it the highest-altitude violent tornado recorded in the United States. At the time, it was the highest-elevation tornado known, since surpassed by several others, including a 2004 tornado above 12,000 feet (3,700 m) in California's Sequoia National Park. While no human fatalities or injuries occurred, an estimated one million trees were felled by the tornado. The tornado damage was originally thought to be the result of strong thunderstorm straight-line winds until the area was surveyed by University of Chicago severe weather meteorologist Ted Fujita and his colleagues, who published a paper in 1989 surveying the tornado's path and discussing its meteorological character.
What was the Teton-Yellowstone tornado?
The Teton-Yellowstone tornado was a rare high-altitude storm that occurred on July 21, 1987, in Wyoming. Meteorologists rated the tornado an F4 on the Fujita scale, making it the strongest and only F4 tornado ever recorded in state history. It struck remote areas including the Teton Wilderness and Yellowstone National Park. The tornado reached elevations between 8,500 and 10,000 feet, which identified it as the highest-altitude violent tornado recorded in the United States at that time.
What was the Teton-Yellowstone tornado wind speed?
The provided text does not specify a numerical value for the maximum wind speeds produced by the Teton-Yellowstone tornado. Meteorologist Ted Fujita assessed the storm intensity based on the severity of tree damage observed during aerial surveys. He noted that the destruction of large Engelmann spruce trees, which were uprooted and stripped of bark, mirrored forest damage he previously linked to F4-rated events. This biological evidence served as the primary metric for his intensity classification.
What was the Teton-Yellowstone tornado path?
The tornado track began in a valley 1.9 miles northeast of Mount Randolph at 1:28 p.m. MDT. It traveled 24.4 miles across the Teton Wilderness and Yellowstone National Park, eventually crossing the Continental Divide. The path maintained an average width of 1.6 miles and reached a maximum width of 2.4 miles. The storm dissipated on the far eastern side of the Yellowstone River Valley at 1:54 p.m. MDT.
How many people died in the Teton-Yellowstone tornado?
Zero fatalities occurred during the Teton-Yellowstone tornado. No injuries were reported, despite approximately twelve people being trapped in the backcountry when the storm hit. Campers near Enos Lake reported hearing a roar like a train, but they did not see a funnel cloud due to the low cloud base. The lack of infrastructure in the wilderness helped ensure that the destructive event did not result in human casualties.
What did the Teton-Yellowstone tornado destroy?
The tornado leveled an estimated one million trees across its 24.4-mile path. It caused significant damage to the Teton Wilderness and Yellowstone National Park, including at elevations exceeding 10,000 feet. The storm specifically uprooted and stripped bark from large Engelmann spruce trees in the area north of Gravel Ridge. Additionally, the event blocked 15 miles of trails, which required federal crews to perform extensive clearing operations for weeks following the disaster.
What caused the Teton-Yellowstone tornado?
Meteorological data suggests the storm developed rapidly in a high-elevation valley. Fujita noted that the area's extreme altitude and the storm's low cloud base likely obscured the funnel from witnesses on the ground. The storm intensified quickly, transitioning from F0 to F4 intensity in less than 3.1 miles of travel. Ted Fujita and his colleagues documented the meteorological character of the event in a paper published in 1989 after conducting comprehensive aerial and ground surveys.
What happened after the Teton-Yellowstone tornado?
The cleanup required weeks of labor from federal workers to clear 15 miles of blocked trails. Total damage costs reached $2.5 million. Local politicians and timber groups lobbied to salvage the fallen trees, but the Sierra Club blocked these efforts to protect the wilderness. Much of the remaining debris subsequently burned during the major Yellowstone fires of 1988, preventing researchers from conducting further on-site investigations of the tornado's impact.
Teton-Yellowstone Tornado Track
The mapped ground track below shows the surveyed touchdown point, damage corridor, and dissipation coordinates recorded by NWS field crews. The Teton-Yellowstone tornado traveled 24.4 miles across Wyoming, Teton Wilderness, Yellowstone National Park. Coordinates are derived from the official SPC historical tornado database.
Was the Teton-Yellowstone tornado the highest elevation tornado ever?
It held that record at the time of the event, but it has since been surpassed by other tornadoes, such as a 2004 storm in California that occurred above 12,000 feet.
How many trees did the Teton-Yellowstone tornado destroy?
The tornado felled an estimated one million trees along its path.
Why did campers not see the funnel of the Teton-Yellowstone tornado?
Fujita hypothesized that the combination of the area's high elevation and the storm's low cloud base made the funnel invisible to observers.
What was the Fujita rating of the Teton-Yellowstone tornado?
The tornado was rated as an F4 on the Fujita scale, remaining the only officially rated F4 or EF4 tornado in Wyoming history.