Summary: April 7, 2020
The first week of April in the Intermountain West saw mainly less than 0.50 inches of new liquid precipitation, with the majority of the southern IMW seeing less than 0.10 inches or no precipitation. The main outlier in the dryness was northwestern Wyoming, where Teton and Park counties saw widespread amounts of up to 2 inches.
March precipitation across the IMW was a bit of a mix, with below-normal precipitation through much of Wyoming, Western Utah, central and southeastern Colorado, and northeastern New Mexico. Southern New Mexico and Arizona were the winners with much higher than normal precipitation. Parts of eastern Utah and northeastern Colorado also saw much above normal precipitation for the month of March.
Looking at the longer-term time scales (90-days and greater) of the Standardized Precipitation Index, the pattern of dryness for much of Utah and much of Colorado is persisting and worsening in southern Colorado and western Utah. Northern New Mexico is continuing to see sustained dryness as well. SPIs for the rest of the IMW, Arizona, the rest of New Mexico and much of Wyoming are near or above the normal.
Now that April is here, the focus from snowpack starts to shift gears to see what that snowpack will do with runoff. Currently, the majority of basins in the Upper Colorado River Basin have near and above normal snow to melt off. Most basins in the UCRB normally see peak snowpack this week. The northern basins are at or above the normal peak snowpack while the southern basins are showing up below normal snowpack. Eyes will soon be on the rivers to see what this snowpack does.
Not helping the dryness that was seen in March was the above normal temperatures seen last month with the majority of the IMW region seeing 2 – 6 degrees above normal temperatures, the warmest areas in southeast Colorado and northeast New Mexico. The western portion of the IMW region was near normal.
The outlook for the next week ending Tuesday, April 14 shows a few systems coming through, mainly benefiting Wyoming and Colorado, however, the majority of the region should see some moisture. The 8-14 day outlook is showing favorable chances of above normal precipitation for the entire IMW region.