Southwest Climate Outlook - February 2016
Originally Published in the Feb 2016, CLIMAS Southwest Climate Outlook
Precipitation: Over the past 30 days, precipitation totals were mostly below average for most of Arizona and much of New Mexico (Fig. 1). Since early January, we have seen persistent warm and dry conditions, linked in part to a ridge of high pressure. Similarly, over the last 90 days, precipitation has been average to below average across much of the Southwest (Fig. 2). However, if we shift our focus to the water year (since Oct. 1), we see precipitation totals much closer to average, and even above average across much of New Mexico (see El Niño Tracker, for more details).
Temperature: Temperatures in January were near average for most of Arizona and New Mexico, but much warmer in February, with much of the region recording above-average temperatures (Fig. 3). The same high-pressure ridge that limited our opportunity for incursions of moisture has facilitated these above-average temperatures, including record-warm days across the region in early February.
Snowpack and Water Supply: Warmer temperatures and below-average precipitation have reduced our previously impressive snow water equivalent (SWE) values back to near average (90–110 percent of normal) across much of the Southwest, with values dipping as low as 50–75 percent of normal across portions of southern Arizona and New Mexico (Fig. 4). This warm-up and dry-out is likely to taper at some point this season, but it remains to be seen how much additional winter precipitation will fall. Given past strong El Niño events, it is reasonable to expect at least some additional precipitation from now into spring.
Drought: Long-term drought conditions persist across much of central and eastern Arizona and the western edge of central New Mexico (Fig. 5). We saw a few runs of average to above-average precipitation, which helped mitigate some of the short-term drought conditions, but multi-year droughts, such as those we experienced during much of the 21st century, will require more sustained above-average precipitation over multi-year periods to fully recover.
El Niño Tracker: We are in the middle of a strong El Niño event, forecast to remain in place through spring 2016. Outside of El Niño’s influence, winter conditions for the Southwest are relatively dry, but the extended hiatus in winter storm activity over the last month is longer than expected. The forecast models for the remainder of February look warm and dry, but this pattern should break eventually, resulting in more winter precipitation events and likely a higher than average cumulative precipitation total by the end of our cool season (see El Niño Tracker).
Precipitation & Temperature Forecast: The February 18 NOAA-Climate Prediction Center three-month seasonal outlook continues to predict above-average precipitation for most of the Southwest this winter, centered on Arizona, New Mexico, and West Texas (Fig. 6, top). Temperature forecasts are split, with elevated chances for above-average temperatures along the West Coast and the Pacific Northwest and increased chances for below-average temperatures centered over Texas and into New Mexico (Fig. 6, bottom).
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