December 8, 2017 (UT, WY, CO)
- The snow season has gotten off to a slow start in Utah and Colorado, especially in the southern portions of those states. Many SNOTEL sites are observing their lowest or 2nd-lowest SWE on record for early December. In Wyoming, by contrast, the snowpack is near normal or above normal in nearly all basins. The outlook through December 17th is for very dry and warm weather across the region.
- The ongoing weak La Niña event is expected to persist into early spring. Historically, weak to moderate La Niña events are associated with below-normal March-May precipitation for Utah and Colorado. This tendency, given the current state of the snowpack, strongly tilts the odds towards an overall below-normal snow season for most of Utah and Colorado.
- October was moderately dry for Colorado and Wyoming, and very dry for Utah (5th-driest October on record). November was moderately dry for Colorado and Utah, and overall wet for Wyoming. Since October 1, the southern two-thirds of Utah, and far southwestern Colorado, have received less than 25% of normal precipitation.
- October temperatures were slightly below normal in Wyoming, and near normal in Utah and Colorado. Last month, Utah and Colorado had their warmest November on record, with most locations running 6-10 degrees F above average, while Wyoming had its 8th-warmest November.
- Since early October, drought conditions have emerged and/or worsened across Utah and western Colorado due to well-below normal precipitation. As of December 5th, 53% of Utah is in D1, with another 31% in D0; in Colorado, 17% is in D1, and 16% in D0; and in Wyoming, only 2% is in D1, and 12% in D0.