Tag: weather

The Creek Fire ran for more than 10 miles and burned 36,000 acres during the first 22 hours after it started at 6 p.m. September 4 northeast of Fresno, California. During that time it created two fire tornados and sent its smoke plume up to 55,000 feet, taller than the tornadic thunderstorms in tornado alley.

An analysis by meteorologists from the National Weather service has revealed that the extreme growth on September 5 generated rare phenomenons — vortices rated at EF2 and EF1, sometimes called fire tornados when they are created by a wildfire.

One was near Mammoth Pool Reservoir and the other was near Huntington Lake. Over 200 people trapped by the fire at Mammoth Pool Reservoir were flown out by courageous National Guard Pilots in helicopters, at times through darkness and smoke.

The NWS personnel rated the vortices based on the effects on trees, including areas where trees were debarked, indicating an EF2 event.

Below is an excerpt from an article by Matthew Cappucci  in the Washington Post.

Jerald Meadows, the warning coordination meteorologist at the Hanford office, said both tornadoes shared common features. “The main contributing factor was the debarking of all the pine trees up with the Mammoth Pool tornado,” Meadows said. “They both uprooted trees to the root balls and snapped large pines. But the [EF1 tornado] did not have any signs of true debarking. We’re probably talking the difference between 100 and 110 miles per hour.”

The Mammoth Pool tornado, which touched down inside the Wagner Campground, snapped several two-foot-diameter trees about 20 to 30 feet above the ground; it was rated as having winds of 115 to 125 mph. The Huntington Lake fire tornado had winds of 90 to 107 mph, and the NWS noted that it was “the result of unprecedented fire activity.”

The article reports that the NWS personnel on duty while the tornados were occurring had concerns about activating their severe weather warning system.

“A tornado warning was considered but not issued,” said [Jerald Meadows, the warning coordination meteorologist at the Hanford Office], who feared that disseminating such an alert might leave people unnecessarily conflicted about deciding whether to shelter or evacuate.

“A tornado warning for a fire opens up a can of worms,” he said. “We want to make sure we’re messaging properly, and we were talking to fire crews letting them know of the circulations we were seeing.”

Before the onslaught of fire tornadoes that has been a hallmark of 2020′s blazes, some National Weather Service offices have had internal discussions and concluded that they would not issue tornado warnings for wildfire-related twisters. While the National Weather Service hasn’t issued specific policy guidance to its 122 forecast offices on how to handle fire tornadoes, Meadows suspects considerable research will be needed to reach a resolution.

This article was edited September 26 to clarify the locations of the fire tornados at Mammoth Pool Reservoir and Huntington Lake.

Thanks and a tip of the hat go out to Tom.