Drier, Warmer Conditions for Fall and Winter Across Panhandle with La Nina

As we move into the fall with winter fast approaching, La Niña conditions are expected to gradually strengthen and continue through the Northern Hemisphere, according  to the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center. Even though the Texas Panhandle is in dire need of precipitation indicated by the U.S. drought monitor in Figure 1, with the La Niña prediction for the fall and winter we can expect a drier than normal winter with milder temperatures. La Niña occurs when cooler than normal sea-surface temperatures (SST) occur in the eastern tropical Pacific ocean, and has many effects on the United States climate. La Niña causes drier than normal conditions in the Southwest in late summer through the winter, drier than normal conditions in the Central Plains in the fall and in the Southeast in the winter. Also, La Niña winters are warmer than normal in the Southeast and colder than normal in the Northwest. Figure 2 shows the SST anomalies for September 28,2011. The cooler temperatures in blue along the equator and off the coast of Ecuador indicate the presence of La Niña.

Figure 2 from the NOAA Climate Prediction Center.

According to the NOAA Climate Prediction Center, roughly one half of the models predict La Niña to strengthen during the Northern Hemisphere fall and winter, and of these models the majority predict a weak La Niña. Also, historical data of SSTs’ since 1950 shows that a second weaker La Niña has occurred in three of the five multi-year La Niñas. The solid yellow line in Figure 3 below shows the median prediction for the forecasted SST anomalies, which indicates a continuation of La Niña through the fall and Winter. Figure 4 and 5 below shows the monthly seasonal outlook from the NOAA Climate Prediction Center for temperatures and precipitation across United States though June 2012. The EC indicates equal chances of A, N or B. The A means above average, the N means normal and the B means below average.

Figure 3 shows the model forecast SST anomalies from September 2011, which is from the International Research Institute for Climate and Society.

Figure 4 from the NOAA Climate Prediction Center shows the monthly seasonal outlook for temperatures across the US through June 2012.

Figure 5 from the NOAA Climate Prediction Center shows the monthly seasonal outlook for precipitation across the US through June 2012.