Summary: March 31, 2020
Even as the engine of human civilization sputters and the gears grind, the natural world motors on. As we advance our calendars into the month of April, days are getting longer at a rapid rate, and temperatures are warming. Snowpack is hitting its peak in the high country, and agricultural lands in the valleys are greening up. Thus, there are a lot of moving parts to this week's summary.
A weather system tracked across the IMW from west-to-east last Wednesday through Friday. This brought generous moisture to northern Utah, with the hardest hit areas receiving over an inch of precipitation. Totals were more modest across the northern Rockies, the valleys, and the eastern plains. However, northeast Colorado did see anywhere from 0.25"-1.00". This was a welcome boon to eastern Sedgewick, Phillips, Yuma, and Kit Carson Counties. Temperatures for the week varied from cooler than normal in the western half of the Intermountain West (IMW), to warmer than normal in the eastern portion. Eastern Colorado and New Mexico were 4-8 degrees above average for the week. This warmth continues a trend in place for much of the month of March. Monthly temperature anomalies were 4-6 degrees above average in SE CO with lots of wind.
By and large, snowpack is in the normal range across the IMW, mostly 90-130 percent of normal. Following a remarkably snowy 2019, and an equally remarkably dry 2018, it doesn't feel quite normal to see normal numbers around peak season. Even the San Juans, which struggled throughout much of the second half of winter, made up ground in the last several weeks, and are now near the normal peak.
Streams and reservoirs are preparing for to receive their annual bounty in the form of snowmelt. While some melting has undoubtedly occured at lower elevations, cooler than normal temperatures over the western half of the IMW mean we haven't seen much snow come off the SNOTEL sites just yet. Streamflows in the San Juans are low, largely due to a hit to base flow during last year's failed monsoon. However, some of these anomalies can be attributed to the fact that snow simply has not begun to melt in the high county. In warm years, it has by this point.
Field reports in eastern Colorado warn of the need for moisture soon. Winter wheat is struggling to green up for some due to lack of moisture, and forage production stands to take a hit. Recent warm and windy weather has exacerbated the situation. The outlook, while favorable other places, is not particularly promising where moisture is needed most. Another storm is expected to impact the IMW mid-week this week, but precipitation will mostly fall north of central Utah and central Colorado. The southeast plains are likely to be in the wind belt. The 8-14 day outlook is promising with increased chances of above normal moisture for the majority of the IMW.
UCRB: The Colorado Climate Center is in agreement with improvements reported in USDM draft #1 to eastern Utah. The Uintah Mountain Range in northeast Wyoming received another 0.50-1.00" of precipitation over the last week, and is above average peak snowpack levels for the water year. Given current water year-to-date precipitation percentiles, the Climate Center recommends these improvements go further into Colorado, covering eastern Moffat County as well.
Eastern Colorado: Reported agricultural impacts from southeast Colorado are concerning at this point. Troubles started back in October, when fields were dry, and winter wheat had to be drilled into the ground. These impacts could have been counteracted with a wet winter, but SPIs and SPEIs for southeast Colorado are near normal over the winter months. March conditions have been poor, with genearlly warm and dry weather and a number of red flag warnings. This has lead to dust events, and in some cases, wheat flying off fields. Forage production will likely take a hit if the rains do not return soon. That said, the area is just now transitioning into the wet season.
Since station data do not support D2 yet, we are going to wait one or to more weeks before calling for expanded D2.
We recommend a degradation from D0 to D1 for northern Huerfano County, and eastern Saguache County. This area is showing D1-level 90-day SPIs, and has been subject to regular red flag warnings as dry, windy conditions persist. Need for irrigation is projected to ramp up much earlier than normal near Walsenburg.
We recommend expansion of D0 in western Pueblo County, and eastern Custer County. Short and long-term SPIs here are a mix of near normal, and much drier than normal.
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