Last week for the Intermountain West region was dry with the exception of spotty precipitation in northern/central Wyoming, along the Front Range of northern Colorado, and southern New Mexico. Wyoming saw up to 0.25″ in most areas except for the northwest corner where counties such as Park saw up to 1.0” of precipitation and a dry spot with little to no precipitation over the southwest corner. Northern Colorado Front Range, Larimer, Grand, and Eagle counties, received 0.26-1.00” of precipitation. Southern New Mexico saw some spotty precipitation, with much of the area seeing 0.01 to 0.25” and Socorro county seeing over 1.00”. North New Mexico missed out on the moisture this week, along with the rest of the IMW region, receiving less than 0.10″ of precipitation.
Despite the dryness, temperatures were below average for the much of the IMW region. The exception is southern NM/AZ where some counties experienced near normal temperatures. However, most of NM/AZ experienced cooler than average temperatures, some northern counties such as Rio Arriba in NM and Navajo in AZ saw temperature departures of 6 to 9 degrees cooler than average. CO/UT/WY was even cooler with the entire area seeing temperature departures of at least 3 to 9 degrees below average while some areas such as western UT and northern WY were even cooler still with temperature departures of 9 to 15 degrees. This was a nice change from the past few months when the IMW experienced temperatures much above normal with Colorado and New Mexico seeing the warmest September on record.
Streamflows in the UCRB are starting to show the recent dryness with an increasing number of stream gauges showing below normal flows. The driest of the gauges are showing up in the headwaters of the Colorado River. The Basin as a whole is still in good shape with the key gauges seeing flows in the normal region.
Outlook is showing low precipitation probability over the whole IMW for the next couple weeks with below average temperatures in WY/CO/NM. UT and AZ are expected to see above average temperatures. A lack of precipitation and above average temperatures in southern UT and northern AZ is something to keep an eye on in the upcoming weeks.