December 12, 2018 (UT, WY, CO)
- A stormy start to Water Year 2019 has led to above-normal snowpack conditions over most of the region and some general improvement in regional drought conditions. The most drought-stricken areas in southwestern Colorado and southeastern Utah have not seen as much benefit from the early-season storms, and the snowpack is below normal in those basins.
- The snow season has gotten off to a good start for the region, with the majority of basins reporting 110-150% of normal SWE for early December. Southwestern Colorado and southeastern Utah are behind with 70-80% of normal SWE, though these numbers are well ahead of last winter's. The current SWE values at SNOTEL sites in the San Juan Mountains are 3-8 times higher than in early December 2017. In Wyoming, the southern and eastern basins are generally above normal, while the western basins are hovering just below normal.
- October was much wetter than normal overall for Utah and Colorado, and slightly wetter than normal for Wyoming, with below-normal temperatures prevailing in all three states. November was was slightly drier than normal for Colorado and Utah, and overall wetter than normal for Wyoming, again accompanied by below-normal temperatures. Since October 1, many areas in Utah and Colorado have received over 150% of normal precipitation. The 3.83" of precipitation recorded at Las Animas, CO, since October 1 is 230% of normal, and more than was recorded from October through June last water year.
- Since early October, drought conditions have improved by one category or more across many parts of eastern Utah and western Colorado. Exceptional drought (D4) remains entrenched in the Four Corners region, however, and it would require many months of above-normal precipitation to fully relieve the drought conditions there. The 2-month EDDI map shows that evaporative demand since the start of the water year has been normal (white) or lower than normal (blue colors) across the region; the 12-month EDDI map still strongly reflects the unusually high evaporative demand throughout the 2018 warm season.
- Sea-surface temperatures are above normal across much of the tropical Pacific Ocean, and the official emergence of El Niño conditions is very likely this winter (>80% chance). If and when it emerges, the El Niño event is likely to remain on the weaker end of the scale. The CPC seasonal precipitation outlooks for the December-February and January-March periods show slightly enhanced chances for above-normal precipitation for Colorado and southern Utah, consistent with historical tendencies during El Niño events.