A storm system has been spinning off the coast of California for a few days and is starting its run toward Colorado early Wednesday. The storm will move across the state without a connection to cold Canadian air. Conditions often vary widely across the state in this scenario, and Thursday should be no exception.
After another very pleasant day with highs in the 50s and 60s on Wednesday, the storm begins to move into the state late this evening. By midnight clouds will be on the increase locally as snow begins to fall over the higher terrain of the western slope with rain or a rain/snow mix on the valley floors.
By Thursday morning as the day gets underway, some of our local mountain areas, the San Luis Valley, and the Upper Arkansas River valley will have snow showers around. For the cities on the Front Range and the plains, the day will look a little bit different with clouds moving in.
Temperatures will be cooler across the region with the storm moving from west to east across the state through the day. But without the attachment to cold air, we expect mainly mid-20s to mid-30s for our local mountain communities and 40s and 50s east of the Rockies.
The storm brings instability with it and it’s possible a flash of lightning or rumble of thunder occurs once or twice with the snow over the mountains. In the late morning and early afternoon, an broken line of thunderstorms should develop from the Pikes Peak Region arcing to the southeast across the plains. At elevation in the Pikes Peak region this is likely to mean areas of rapidly changing conditions with bursts of snow producing low visibility and quick accumulations of heavy, wet snow. Don’t be surprised if you hear thunder here too.
As the afternoon heads toward evening, the storm circulation strengthen over the eastern plains. The transition to the backside of the storm will drop the snow elevation for the last few hours of daylight and into the evening, likely bottoming out at about 5,500′.
The wind gets strong as this happens with evening and overnight gusts between 30 and 50mph east of the mountains.
Areas that receive snow are likely to see deteriorating travel conditions and in some cases the changes may be quite rapid. Roads may quickly slush up or become snow packed, visibility may drop to near zero, and even though it will be a heavy and wet snow, the wind may blow it around.
The storm will quickly exit the area early Friday morning.