April 10 briefing from the Western Water Assessment: March disaster for snowpack

Westwide SNOTEL snow water equivalent as a percent of normal April 17, 2015
Westwide SNOTEL snow water equivalent as a percent of normal April 17, 2015

Click here to go the the Intermountain Climate Dashboard from Western Water Assessment. Here’s an excerpt:

Highlights

  • March was disastrous for the region’s snowpack and the expected spring–summer runoff. Snow conditions and forecasted runoff are now similar to 1977, 2002, and 2012 in many parts of the region, particularly in Utah.
  • March brought a double-whammy of well-below-average precipitation and near-record warmth over most of the region, including nearly all mountain areas.
  • Since early March, the snowpack has significantly declined relative to normal conditions across the region. Most basins are now reporting less than 70% of median SWE, and the majority of individual SNOTEL sites are below the 5th percentile for SWE.
  • The April 1 spring-summer runoff forecasts are lower or much lower than the March 1 forecasts across the region. Most forecast points are now expected to see much-below-average (50–69%), far-below-average (25–49%) or extremely low (<25%) runoff, with Utah seeing generally lower forecasts than Colorado and Wyoming.
  • El Niño conditions have strengthened slightly in the last month and are expected to continue at least through the summer. The wet tilt in seasonal precipitation forecasts for parts of our region is predicated on a typical El Niño influence over the next several months.
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