Summary: June 19, 2018
Last week the Intermountain West saw the remnants of Tropical Storm Bud roll through from southern Arizona, New Mexico and Colorado. Utah and western Arizona remained dry for the week with less than 0.10" of precipitation. New Mexico saw widespread precipitation amounts of at least 0.50" with isolated areas over 1.00". Colorado was a mix of beneficial precipitation, and lack of precipitation. Northwestern Colorado from Moffat to San Miguel counties were on the drier end with less than 0.25 inches. Southwestern Colorado saw some of the best precipitation for quite a while, with amounts of 0.50" to over 1.00". While this was above normal precipitation for this time of year and helped firefighting efforts, it was not enough to put out the fires or make up for the large precipitation deficits this area has seen over the last 9+ months.
Eastern Colorado saw a mix of precipitation amounts. Northeastern Colorado saw widespread areas with at least 0.50" and isolated areas over 1.00". Southeastern Colorado missed out on most of the precipitation with much of the Arkansas Basin seeing less than 0.25". Extreme southeastern Baca and extreme eastern Prowers counties saw amounts of 0.25 - 1.00" last week. This is near or just above normal for a week this time of year. While this precipitation helped the area out, it isn't helping to fill the deficits that have accumulated this winter and spring.
Even with precipitation in southern Colorado SPIs remain low on all time scales, worsening on the longer times. Snotel precipitation percentiles remain extremely low in the San Juan and Sangre de Cristo Mountains, still in the 0 - 3rd percentiles.
Streamflows in the UCRB are continuing to fall and the majority of streamgages are reporting much below normal, including our three indicator sites. Streamflows in eastern Colorado are slightly better, with gages in the mountains showing normal flows, but most gages on the plains are showing below normal flows.
Temperatures remained above normal for the entire IMW region, with the exception of northern Wyoming. Higher temperatures mean higher evaporative demands, which means what rain did fall will be sucked out by the atmosphere faster.
UCRB: Status quo. Despite the 0.50 to 1.00" that fell through southwestern Colorado, the accumulated deficits still warrant the current depiction.
Eastern CO: The USDM Author is suggesting reduction of D3 in Baca, Prowers and Kiowa counties based on recent precipitation. We are fine with reductions in extreme southeast Baca County, but not as far north and west as is suggested. See change map on the right. Since most of the precipitation that fell in eastern Colorado was near normal for a week in June, we don't feel it was enough to make up accumulated deficitsand improve conditions.
There is also a suggestion to trim D1 in Cheyenne County. We are on board with this suggestion given the bullseye of precipitation where the improvements are being suggested. Along with this improvement are reductions of D0 in Kit Carson County and reduction of D2 in Lincoln County. While Kit Carson County hasn't see much precipitation this month, only 0.1 to 0.25", based on precipitation in May, D0 could be removed.
We would like to hold off on the D2 reduction in Lincoln County. There was beneficial precipitation, however it was not enough to recover the deficits accumulated this winter and spring.
Visit the U.S. Drought Monitor