CSU Collegian/Coloradoan article about Colorado Severe Weather Season
From early May to mid-June, Scott Longmore watches weather patterns even more than usual, indulging in his passion of photographing supercells, wall clouds, mesocyclones and, if he's lucky, a tornado.
Longmore, a trained meteorologist, has been "chasing" storms for 25 years.
"As a meteorologist, it's very fascinating for me to watch these storms form and predict where they are moving and what they will do," said Longmore, who develops software programs for Colorado State University's Cooperative Institute for Research in the Atmosphere.
Longmore isn't the only one at CIRA fascinated by the storms.
His colleague, Dan Bikos, makes up the other regular member of the informal chase team. When they go out, one drives, one navigates and others watch a weather radar display software that also shows other "chasers" in the area. (There were more than 100 chasers watching a late May storm near Aurora, Colorado.)
"Three people is ideal so you know where to go and how far away to be," Longmore said.
Unlike other "chasers," Longmore and his colleagues aren't interested in getting as close as possible to a storm. They prefer to stay a safe distance away and know which roads in the area can be escape routes if a storm suddenly changes direction.
Their interest primarily is professional curiosity. They want to watch a storm take shape and predict its path and try to understand the conditions that can cause a mesocyclone –a spinning thunderstorm – to turn into a tornado.
"It really tests your skills as a meteorologist," Longmore said. "You want to see if the predictions you made while observing storms were accurate. It's a validation of your forecasting skills."
Those reasons drive many meteorologists to "chase" storms, said Matt Rogers, a fellow CIRA research scientist.Rogers followed storms as a graduate student and still does from time to time. Several graduate students in the Department of Atmospheric Studies also chase them.
"It's a challenge for forecasters and a good way to test their skills," he said. "The goal is to be there when the storm forms so you can see its structure."
Q&A with Scott Longmore
How many storms have you "chased" this year?
How many storms do you usually chase in a year?
Five to 10 a year.
Is this year more active than in years past?
It does seem more active than "average" years, but I would have to wait until the end of spring for an accurate assessment. This year's severe weather episodes have lasted longer – four to five days in duration - compared to the one- to two-day episodes we normally see.
What is the difference between a tornado and a mesocyclone?
A mesocyclone is a vertically oriented rotating updraft within a supercell thunderstorm. A tornado is a violently rotating column of air that connects the base of a thunderstorm to the surface.
Tornadoes generally, but not always, form underneath a supercell thunderstorm mesocyclone. They can form under non-supercell thunderstorms in other types of weather environments, but it doesn't happen often.
How far have you travelled to see a storm?
I've storm-chased as far as eastern Nebraska, Kansas, and Oklahoma.
A tornado recently was reported in the Red Feather Lakes area. Is that unusual? If so, why?
Yes, it is unusual. The vertical wind patterns that are favorable for forming supercells and tornadoes are usually found on the plains, Midwest and southern states during the spring. The complex terrain in the mountains usually disrupts these conditions.
The last time a tornado formed in the northern Colorado Rocky Mountains was the Pingree Park tornado on June 18, 1987, at an elevation of about 9,000 feet.