Summary: May 5, 2020
Dryness prevailed through most of the Intermountain West Region in April. Must of western and southern Colorado saw the driest or one of the driest Aprils on record. Northern Utah also got in on the extreme dryness that was April 2020 with the Salt Lake area seeing some of their lowest April precipitation amounts on record. For both Utah and Colorado, this was an inopportune time to see this much dryness since April is still a wetter month of the year. Continuing with the dry theme of the week, eastern Colorado started off the growing season with much below normal precipitation. Some wetter spots in the IMW region included north-central Colorado, northwestern Wyoming, and parts of Arizona and New Mexico, see normal or above-normal precipitation.
The first week of May has seen the dry pattern continue except for northern Colorado and southeastern Wyoming where thunderstorm season has started up. Precipitation amounts ranging from 1.00 to over 2.00 inches has fallen over northeast Colorado and southeast Wyoming. The rest of the IMW saw little to no precipitation.
Typically by this time of year the snowpack season is in full snowmelt form with the occasional May storm that brings a pause to melt and a small increase in the snowpack. This means we have passed the peak snowpack of the year. Most of the IMW saw near normal peaks, with many on the lower end of normal. With little snow in April and a quick warmup, the snowpack is melting quickly.
The quick snowmelt means streamflows are starting to come up. Most of the streams with above normal flows means the snow is melting quicker and earlier than normal. We are seeing above normal flows in the headwaters of the Colorado River and the Yampa River. However, we are also seeing below normal flows on the White, Colorado, Gunnison, San Miguel, and San Juan Rivers. Our three main sites are barely in the normal flow range.
Temperatures for April were not as bad as most years with the dryness we’ve seen. Most of the northern portion of the IMW region saw below normal temperatures and the southern portion saw near normal temperatures, with some isolated warmer spots. One of the areas much above normal is southwestern Colorado and the Rio Grande River Basin, which did not help the lack of snowfall. More recently, the last week’s temperatures across the IMW have been 6+ degrees F above normal.
Little precipitation is forecast to hit our region with small amounts in the higher elevations. The 8-14 day outlook is hinting at chances of above normal precipitation with New Mexico looking dry.