Summary: October 29, 2019
While the majority of the Intermountain West experienced below average temperatures last week, many spots remained dry. Most of Utah, Arizona, and New Mexico received less than a tenth of an inch of moisture last week, with larger accumulations focused over the Continental Divide and mountains in Colorado, the I-25 corridor, and many locations throughout Wyoming. Month-to-date, the Four Corners region has mostly missed out on the moisture. Monthly climatological contributions indicate that October is an important precipitation month for eastern Utah, and unfortunately, they have not received much.
On a positive note, we’ve had a solid start to the snowpack accumulating season. Although early, it is promising to see percentiles near and above the median for snowpack throughout the IMW as of October 28. The lowest percentiles (which are closer to 50, or near average) are scattered along the central UT mountains and the San Juans in southwest CO.
Streamflows are still in okay condition in the Upper Colorado River Basin as they remain near baseflow. Expect many of the gages to go “offline” as they become ice affected over the coming days and weeks. Soil moisture is showing quite a bit of drying, thanks to a hot and dry summer and lack of monsoon. Since the soils will be freezing and not thawing for the rest of the cold season, moisture doesn’t matter much now. But those dry soils will come into play again during the spring thaw.
Cold conditions will continue over much of the region this week, but warming will return to the southern part of the IMW in early November. While some more precipitation accumulations are expected (mostly over Colorado) this week, there is an increased chance for drier than average conditions returning to the region.