Regions of Colorado

Denver sits on the hinge between the plains and the Divide, and the forecast changes with the ground under it — upslope storms that wrap moisture back into the foothills and bury the city, the costliest hail corridor in the country, Chinooks tearing downslope off the mountains, and an I-70 climb where the weather turns over every thousand feet.

Boulder sits at the exact spot where the plains hit the wall, and everything here follows from that. Upslope storms stall against the Front Range and drop their heaviest snow on this county, the 2013 flood came out of these canyons, and the Chinooks and the Marshall Fire wind run downslope through town at highway speed.

Nothing here is far from the mountain. Pikes Peak stands 8,000 feet over Colorado Springs and writes the weather for everything under it — upslope snow that piles on the west side while the plains stay bare, hail that made this the costliest corridor in the country, summer lightning above treeline on the Peak, and the burn scars that turn a thunderstorm into a flood warning.