Thursday, September 9, 2010

La Nina Expected Thru Winter

Cooling of the surface waters of the Equatorial Pacific west of South America continues, and these La Nina conditions are expected to persist through the Northern Hemisphere Winter 2010-2011. Large negative anomalies (cooler than average surface temperatures) started in June, and continue to deepen. In the Fall, Virginia is typically about average for temperatures and drier than normal during a La Nina. That does not bode well for our drought situation right now. So what type of weather typically happens in the U.S. when we have a La Nina Winter setup?
(here's another view of the same information...)
In Virginia, we're right on that borderline of wet versus dry conditions, but there tends to be at least one of the jet streams dipping or tracking right over us, allowing storm tracks to head our way. That may be able to bring us the precipitation we sorely need.