Several possible tornadoes touched down in Rim Country this week, shearing off a small forest of trees, but not inflicting the widespread damage visited on Bellemont.
Multiple tornadoes that knocked over powerlines, plucked up trucks and trailers and ripped the roofs off houses in Bellemont got most of the media attention, but twisters also touched down in several places atop the Rim — cutting a swath of pines.
A stretch of forest reportedly 3 miles wide and 13 miles long along Forest Road 141 south of Clint’s Well on the Rim above Strawberry suffered huge devastation at about 5 a.m. on Wednesday — with hundreds of big ponderosa pines snapped off 15 feet above the ground.
“It was unreal,” said Roger Rohrbach, a Payson man who drove through the area Wednesday afternoon on his way home from a hunting trip. “It looked like St. Helens — like a bomb had gone off. They were piled up like pickup sticks.”
Reportedly, another possible twister or microburst struck in Little Valley, just south of the Blue Ridge Reservoir. In that case, the fierce winds closed the highway, with piles of uprooted and snapped off trees.
The tornadoes skirted Rim Country towns and subdivisions, leaving Bellemont to bear the brunt of a fluke storm that spawned an almost unheard-of chaos of twisters.
The U.S. Weather Service rain gauge in Payson recorded two-tenths of an inch, on the edge of a storm that dumped 1.27 inches in Flagstaff and spawned dozens of tornadoes.
Officially, Payson has received 17.62 inches of rain this year — just barely behind the long term average. Flagstaff, on the other hand has gotten 22.2 inches, compared to a long-term average of 17.7 inches, according to Daryl Onton, a Weather Service meteorologist based in Flagstaff.
Unofficial rainfall totals posted on the Astro Computer Services Web site yesterday put Payson’s 24-hour total at just under an inch, with 1.29 inches already in October and 20.32 inches for the year so far.
Rim Country also got the first snow flurries of winter, both atop the Rim and in Pine — although only the hailstones stuck.
The unusual conditions that spawned the violent weather broke up Wednesday as the storm front moved north, spawning widespread freeze warnings north of I-17 on Thursday. The Weather Service now predicts partly cloudy skies in Rim Country through the weekend, with highs in the mid 70s and lows in the mid 40s. However, temperatures should drop below freezing above 6,500 feet.
The violent storm acted like an unholy offspring of a winter storm and a summer monsoon, said Onton.
“The low-pressure pattern was typical of the pattern we see in the winter, however it interacted with moisture that it drew up from Mexico — similar to what we see in the summer. That combination produced a lot more instability than we would see in a winter storm,” said Onton.
Blame a low pressure system that crouched above Southern California for days, sucking in cold, wet air from the Pacific and warm, wet air from the Gulf of California.
The clash between these converging air masses generated a violent storm and an unprecedented number of tornadoes, said Onton.
The key to the storm’s destructive power lay in the dramatic difference between conditions close to the ground and the maelstrom raging in the heart of the storm at 20,000 feet.
Four miles overhead, the howling 50-mile-an-hour winds carried a mass of wet air chilled to about 1 degree. Down on the surface, the temperature stood at closer to 47 degrees and the wind speed at about 10 miles an hour.
That stark difference in temperature and wind speed, called wind shear, produced a violent storm, with huge hailstones and twisters where the two air masses met.
Onton said he was working in the Flagstaff weather service forecasting office when the storm rolled in, heralded by the intense colors showing suddenly on the radar screens. He said no one has seen such a storm in the area since the weather service deployed high resolution weather radar some 20 years ago.
“It was a very impressive storm. Unfortunately, it was very damaging — it hit the community hard.”