12:00 noon, Friday, February 20, 2015
Over the last few days we have been watching the development of a significant winter storm for Wyoming and Colorado. The biggest change over the last few days is a slight shift of the storm’s main focus to the south and west, and a later arrival of the most intense part.
GENERAL FORECAST FOR COLORADO/SOUTHERN WYOMING
Intermittent precipitation is likely this evening into Saturday morning (possibly starting as rain in the lower elevations). It will be mainly north of I-70 in the mountains, and north of Colorado Springs along the Front Range. It is likely to be a nuisance type, with 0-3 inches of snow, except in the north-central mountains of Colorado and the Laramie Range of Wyoming where roads may get rough in some heavier snow.
From late morning through afternoon Saturday a strong cold front should move from Wyoming and down the Front Range of Colorado and initiate a more serious period of snow Saturday afternoon through midday Sunday. The potential for heavy snow south of Colorado Springs and in the mountains south of I-70 is likely to last well into Monday. An additional 6-12 inches is likely in the lower elevations during this period (except less than 6 in the northeastern Colorado plains east of Greeley and Longmont). 10-20 inches is likely in the mountains with some of the central and southern Colorado mountains perhaps exceeding 20 inches in some locations.
SPECIFICS FOR COLO SPRINGS-DENVER-BOULDER-FORT COLLINS
In a nutshell… relatively minor impacts tonight through Saturday morning, more serious snow with winter road conditions Saturday afternoon/evening through midday Sunday, probably minor impacts Sunday afternoon through Monday but with more uncertainty during this last period regarding another round of heavy snow.
Most likely accumulations:
This evening through Saturday morning 0-3 inches.
Saturday afternoon/evening through midday Sunday, an additional 6-10 inches lower elevations with the most south of a line from Lyons to DIA, 10-16 inches in the mountains.
Sunday afternoon through Monday; this period is the most uncertain depending on the location of the storm to our southwest. 0-2 inches in Larimer and Weld counties, 1-4 inches in the Denver-Boulder area, 3-6 inches in the south Denver suburbs and south. These accumulations do not include a small chance that a period of heavier snow may occur in the Denver-Boulder area late Sunday or early Monday.
3-day totals: 6-10 inches Cheyenne-Fort Collins-Longmont; 8-14 inches Boulder-Denver-Colorado Springs. 10-20 in mountains and Palmer Divide with the heaviest mountain totals are a little more likely south of I-70.
It appears that we won’t warm up too much this time before the next surge of cold air and snow, probably late Wednesday or Thursday.