La Nina may be returning
Cooling waters in the eastern Pacific have some scientists thinking that La Nina may be returning. The definition of a La Nina is when the 3-month running mean temperature anomaly in the equatorial Eastern Pacific cools below -0.5°C for five consecutive months. In January the 3-month running mean as of January 1 was -0.4°C, so conditions are still considered neutral. Some of the computer models are predicting that La Nina will return before May, and if that happens, it will have effects on our weather in the Carolinas.
It would be unusual if a La Nina did develop, because our last La Nina just ended in May, 2008. There have only been two instances since 1950 where separate La Ninas developed two years in a row.
The last La Nina occurred from mid 2007 through mid 2008, and it coincided with severe drought across the Southeast. One of the characteristics of a La Nina is dry weather in our part of the world, and if a La Nina does develop, expect another dry summer. A La Nina can also bring an active hurricane season. When a La Nina develops in the Pacific, wind shear weakens in the tropical Atlantic, making it easier for tropical systems to develop and strengthen.
Based on the potential for a La Nina, NOAA’s Climate Prediction Center has released their three month forecast for precipitation for February through April, and it calls for below normal rainfall in the Southeast.
Posted by
on 02/10 at 06:52 PM
