Summary: February 12, 2019
Last week was a very climatologically typical winter week for the Intermountain West - low elevations experienced windy days with a couple of small accumulating events, while the high elevations throughout the Upper Colorado River Basin received between half an inch to over 2 inches of moisture. For most of the IMW, temperatures were a bit cooler than average, with much colder than average temperatures in parts of Wyoming.
Since the beginning of the calendar year, snowpack has rebounded in many of the areas of concern. Mountain ranges in southern CO and western WY that had been struggling at the beginning of the winter season have seen a bump. Now, most of the basins in the IMW show near to above normal snowpack, which is a strong indicator of heading toward a better runoff season this spring.
Short-term standardized precipitation index (SPIs) show that developing dryness throughout New Mexico may be a concern and should be monitored closely. A widespread wet signal shows up throughout Utah, though there are still some low lying areas that are drier. And given the water supply concerns at the beginning of the cold season, they are not out of the woods yet, in terms of drought.
The outlook shows a continued active and wet pattern for much of the IMW. High elevations are expected to receive an addition half to 3 inches of precipitation over the next 7 days. And the 8-14 day outlook indicates an increased likelihood of wetter than average conditions to continue, along with colder than average temperatures. The area that may be missing out on all this excitement over the next week will be southeast NM.
UCRB: Some improvements are recommended in northern UT and western CO. Most improvements were limited to areas that received a surplus (above and beyond their average) of half an inch of moisture since the beginning of the month. In these regions of improvement, SNOTEL snowpack sites are mostly above the 50th percentile, water year precipitation is near to above average, and SPIs on all time scales show improvements. In southwest CO, there are no more SPIs below -2 on the 12-month timescale.
We will continue to be conservative with improvements over the region as we wait to see how the snowpack will translate into actual water supply. Reports of recent high wind events, and very dry soils and low streamflows at the beginning of the cold season, are all going to play a role in determining how much of a recovery the region is experiencing. If the time for major improvements comes, it will likely be during the critical snowmelt/runoff season.
Eastern Colorado: Status quo is recommended for eastern CO this week. Much of the region has received little to no precipitation since the beginning of the month. This is a time of year when a larger number of dry days (or very small accumulation days) is common. Some consistent small accumulating events have helped prevent total drying of the soils. Colder temperatures over the next couple of weeks will also help to minimize impacts of dry spells.
Visit the U.S. Drought Monitor