Seasonal Drought Outlook

 (through January 2013)
Data Source(s): NOAA-CSClimate Prediction Center (CPC)

This summary is partially excerpted and edited from the October 18 Seasonal Drought Outlook technical discussion produced by the NOAA-Climate Prediction Center (CPC) and written by forecaster A. Allgood.

Drought is expected to persist or intensify in Arizona and most of New Mexico in coming months (Figure 10). The NOAA-Climate Prediction Center (CPC) seasonal precipitation outlook calls for equal chances that rain and snow amounts will be above, below, or near average in the Southwest. The drought forecast for Arizona and New Mexico is in part based on the inability to forecast precipitation with very much confidence this year, which is, in turn, related to the uncertainty in the El Niño Southern Oscillation (ENSO) forecast. ENSO currently is projected to evolve into an El Niño, which typically would enhance rain and snow in the Southwest, but the signal of ENSO has been waning in recent months, leading to increased uncertainty about expected winter precipitation.

In California, drought is expected to improve in many regions as a result of recent precipitation and the expectation for more rain and snow. The November–January period historically is wet throughout much of California, and coastal regions receive more than 50 percent of their annual rainfall during this period. Even though California is also influenced by ENSO, the forecast for improved drought conditions is based more strongly on the historical occurrence of rain during coming months.

In the Rocky Mountains, 28-day streamflows remain generally below average across the central Rockies. The CPC 6–10- and 8–14-day forecasts indicate enhanced chances of below-average precipitation for the central and southern Rockies, while the monthly and seasonal outlooks depict equal chances for above-, below-, or near-average conditions. Based on current conditions and the outlooks, drought persistence is expected in the Rockies, but CPC states that confidence in this forecast is low.
 

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