November 6, 2012

October saw the dryness of the 2012 water year continue, with nearly all of the region drier than average since October 1 except for scattered areas in southern and western Wyoming and extreme northeast Utah, according to the HPRCC Water Year Precipitation map. Portions of northwest Colorado, southern Colorado, and central and southern Utah saw less than 25% of average precipitation for the month. The latest US Drought Monitor, released November 1, shows nearly all of the region still classified in severe (D2) or worse drought conditions. There was little change in the drought conditions across the region during September.

We are still very early in the snow season, and the long-term average SWE for November 6 at many SNOTEL sites is less than 1". Thus the percent-of-average data reported in the Current Basin Snowpack map from NRCS may not be a reliable measure of conditions. That said, examining only reports from the high-elevation/high-accumulation SNOTEL sites confirms the impression from the map that the snowpack is above-average in northern Utah, and generally below average in the rest of the region, with Colorado basins being well below average except in the north-central mountains.

Compared to early October, there are now more stream gages across the three states reporting below-normal (yellow) and much-below normal (brown) current streamflows, especially in western Colorado and northern and eastern Utah. Four gages in Colorado and one in Wyoming are showing record-low flows for the date (November 5).

The latest monthly and seasonal Climate Outlooks released on October 18 by NOAA CPC continue to show equal chances (EC) for above-normal or below-normal precipitation for the October through January period, reflecting the likelihood of either ENSO-neutral or weak El Niño conditions during this period, as seen in the IRI's mid-October ENSO Prediction Plume. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures, consistent with the long-term trend towards warmer conditions. [The preceding text is unchanged from the October 23 briefing]. The latest CPC Seasonal Drought Outlook released November 1 projects that the drought conditions across our region will persist through at least January 2013.