A trained weather spotter reported a brief tornado touchdown in northeastern Weld County Wednesday morning.
The twister dropped down in a field at 6:37 a.m. for about 30 seconds to a minute, Fredin said. There was no damage or injuries.
A tornado dropping in the early morning hours is “extremely rare,” meteorologists say.
“Nocturnal thunderstorms over northeastern Colorado are fairly common from late July to early September,” said Kyle Fredin, a meteorologist for the National Weather Service in Boulder. “What's not so common is tornadic storms between midnight and 7 a.m.”
We now have confirmation of a tornado on the ground in NE Weld County near the Pawnee National Grassland. Very few people live in this area but the tornado is getting a bit closer to the 100 or so people in New Raymer. #cowx #4wx @KOANewsRadio @BrittMorenoTV @CBS4Dom @ChrisCBS4 pic.twitter.com/aS6iFqRs8v— Ashton Altieri (@AshtonCBS4) August 8, 2018
Colorado typically sees late night and early morning thunderstorms this time of year with the North American monsoon that lasts from late July through early September. The monsoon brings moisture from the Gulf of Mexico over the Rockies and onto the plains, Fredin said.
Sometimes, the afternoon storms turn severe with wind, hail or tornadoes if there’s enough daytime heat from the sun. But a change in wind direction and height — called a "wind shear" — on Wednesday morning produced just enough of a rotation in the atmosphere to cause the tornado, Fredin said.
The state has seen other rare tornadoes this year. One touched down near the Weston Pass fire in early July and two others were reported in higher elevations outside Steamboat Springs and Jackson County. However, Fredin wouldn’t call them “weird” and said its due to the hotter weather.
“We’ve had warmer weather in June in the early portion of July than what we typically see this time of year,” he said. “Depending on the afternoon, you’ll have some thunderstorms that produce just heavy rain. Sometimes they’ll be thunderstorms that will contain larger hail, and then some thunderstorms will become tornadic."