By David Emory Stooksbury
University of Georgia
Atmospheric-oceanic patterns have a major influence on the type of winter we have in the Southeast. The best known large-scale atmospheric-oceanic pattern is El Nino. Under the El Nino pattern, much of Georgia has a wetter-than-normal winter.
The opposite pattern is called La Nina. During a La Nina winter, much of the Southeast is drier than normal.
Both El Nino and La Nina patterns tend to keep extremely cold air from making it from Canada into the deep South. Thus, damaging freezes are less likely during El Nino and La Nina winters.
No protectionThis winter, though, the atmospheric-oceanic system is in the neutral pattern. It's neither El Nino nor La Nina. During winters with the neutral pattern, extremely cold air from Canada is usually able to invade the Southeast.
This extremely cold air can cause significant freeze-related damage. Between periods of very cold air, the Southeast should have periods of relatively warm air.
Across extremely south and coastal Georgia, the likelihood of temperatures below 20 degrees this winter is at least one and half times greater than we would expect during an El Nino or La Nina winter.
Across much of Georgia, the probability of temperatures below 14 degrees is at least one and half times greater than we would expect during an El Nino on La Nina winter. Temperatures around 14 and below can cause extreme damage to Georgia winter crops, especially onions.
Maps and detailed expectations concerning the extreme freeze probabilities may be found on the Web at www.coaps.fsu.edu/climate_center/frz04.html.
The extreme freeze probability analysis and maps were produced by the Southeast Climate Consortium. The consortium is an outreach and research cooperative between the University of Georgia, Florida State University, University of Florida, University of Miami and the University of Alabama at Huntsville.
(David Emory Stooksbury is the State Climatologist of Georgia and a professor of engineering and atmospheric sciences in the University of Georgia College of Agricultural and Environmental Sciences.)
(David Emory Stooksbury is associate professor of Biological and Agricultural Engineering at University of Georgia's College of Agricultural and Environmental Sciences.)