News & Updates

Originally published in the May 2015 SW Climate Outlook

Precipitation: In the past 30 days, most of New Mexico and much of central Arizona recorded well above-average precipitation (Fig. 1). Climatologically, this is one of the drier times of year for the Southwest, so any substantive precipitation during this timeframe is generally unexpected but welcome, as it helps tamp down fire risk. Water year observations since October 1 demonstrate the persistent and ongoing drought, with most western states, including Arizona, recording large areas of below-average to well below-average precipitation (Fig. 2). New Mexico and the eastern side of Colorado, Wyoming, and Montana have benefitted from some late season storms, but that rainfall on the other side of the Continental Divide, does not necessarily help the water situation in the Southwest.  (read more)

Image Source - NOAA/NWS - Advanced Hydrologic Prediction Service

Image Source - NOAA/NWS - Advanced Hydrologic Prediction Service

This was originally published in the April 2015 Southwest Climate Outlook

Strong signals in early 2014 stalled, delaying El Niño’s onset until last month, when ocean-atmosphere coupling and an additional Kelvin wave indicated more favorable conditions. Despite this late start, El Niño continued for a second consecutive month. Recent increases in sea surface temperature (SST) anomalies (Fig.1 - 2) and ongoing convective activity associated with El Niño-favorable conditions indicate we might be witnessing a two-year El Niño event. These forecasts rely on projections during a time of increasing uncertainty, and the so-called “spring predictability barrier” continues to make it difficult to anticipate how seasonal changes will help or hinder El Niño. (read more)

Precipitation: In the past 30 days, most of the southwestern U.S. received below-average precipitation (Fig. 1). The winter wet season is wrapping up, and instead of above-average precipitation (as many of the El Niño influenced seasonal forecasts suggested), water year observations since October 1 show below-average precipitation across much of Arizona and portions of New Mexico. The situation is direr in other western regions, with California, the Pacific Northwest, and the Intermountain West recording significantly below-average winter precipitation (Fig. 2). (read more)

This presentation will focus on ongoing work to better understand the effects of temperature on water supplies in the upper Colorado River basin. Overall, spring and early summer temperatures explain only a small portion of the variance in water year streamflow in the basin. However, in a subset of years (both warm and cool), temperatures appear to have a stronger influence on streamflow than might be anticipated, given the precipitation. The presentation will also touch on the challenges associated with incorporating the input of water resource management partners, a central component of the project design. (read more)