SECC Summer Climate Outlook
Date updated: May 21, 2008
Current Conditions
Southeast dries out quickly. A fairly strong La Niña (colder than normal waters in the eastern and central tropical Pacific, opposite of El Niño) developed last fall and reached its peak intensity in February of 2008. La Niña usually brings warmer than normal temperatures (2 to 5 degrees F) and drier conditions (30% to 50% less than normal) to Florida and coastal Alabama and Georgia in months of November through March. Fortunately, this past winter was somewhat atypical for La Niña as far as rainfall is concerned. Florida saw fairly close to normal rainfall amounts this winter, while north Alabama and north Georgia remained on the dry side.
More recently, the latter half of April and the first half of May brought a 30 to 40 day stretch with little rainfall, especially over the peninsula of Florida. This stretch dried upper layers of the soil and vegetation quickly and has led to an outbreak of wildfires in east central and south Florida. However, such dry stretches are not unusual in the spring and wildfires are a fairly common occurrence in Florida during this traditional peak wildfire season. According the U.S. Drought Monitor, drought conditions have eased a little over the hardest hit areas of North Alabama and North Georgia, but have intensified over peninsular Florida.
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In other areas, water resources remain strained in North Alabama, North Georgia, and South Florida. For more information on the ongoing drought conditions, including a statement by the Georgia State Climatologist, see the following links.
For more detailed information on recent weather, please see the resources below:
- U.S. Drought Monitor
- Georgia Drought Statement
- Southwest Florida Water Restrictions
- South Florida Water Restrictions
For more detailed information on recent weather, please see the resources below:
- Florida Automated Weather Network
- Georgia Automated Environmental Monitoring Network
- Alabama Office of the State Climatologist
- Southeast Regional Climate Center
- NWS Radar-derived Precipitation Totals
Climate Outlook
Normal patterns should set in as summer begins. La Niña has weakened considerably since February and the Pacific Ocean is now close to what could be considered Neutral conditions. Regardless of the state of the Pacific, La Niña has very little impact on summer climate patterns in the Southeast. Summer climate in the Southeast is characterized by hot, humid conditions and convective thundershowers. Coverage and frequency of these afternoon thunderstorms is higher in Florida and extreme South Georgia, but more "hit and miss" in the remainder of Georgia and Alabama. While normal summer rainfall is not enough to make up for the long term deficits, these rains may mitigate drought effects in selected areas.
Over much of inland Alabama and Georgia, this is the time when evapotranspiration begins to exceed normal rainfall, thus ending most meaningful recharge of surface and groundwater until the following winter. Summer does bring frequent afternoon thundershowers, but the scattered nature of these convective render them insufficient for large scale recharge for the most part. Given that we are entering this critical period with enduring deficits in river flows, lake, reservoir, and groundwater levels, drought will likely remain a critical issue in North Alabama and North Georgia.
Over Florida, the onset of the summer rainy season is usually anywhere from mid-May to early June. The summer rains effectively end the wildfire season in the state, but potential for large fires will continue until rains begin in earnest. The wildfire season rarely lasts past mid-June. Unlike Georgia and Alabama, summer is the season for recharge in Lake Okeechobee. Last summer's rains were not sufficient to bring Lake levels back to normal, so we are entering the season with near-record low levels once again.
The tropical season greatly affects rainfall amounts and coverage during summer in the Southeast. One or several strikes by tropical systems, whether a hurricane or just a weak storm or depression, can bring beneficial rainfall that is a normal component of the climate. This season is forecasted to be active again, so let us hope for a good dose of tropical rainfall that was missed out on last year.
Reasons for optimism? If La Niña continues, May and June actually bring patterns that favor more rainfall than normal over Alabama, western Georgia, and the Florida Panhandle, on average from 5% to 10%. While this forecast can be viewed with optimism, there is less confidence in forecasting using La Niña climate shifts at this time of year. Sea surface temperatures reach their peak departure from normal in the winter months and are in the process of returning to normal by the summer. Also, the active jet stream has migrated north to its summer position, so the tropical Pacific has less influence on it and corresponding weather patterns. As far as temperatures go, La Niña does not favor any significant shifts in average temperature during the spring and summer seasons. For more detailed information on El Niño/ La Niña climate shifts in your particular county, please refer to the Climate Risk Tool at AgClimate:
La Niña nearly over, or is it?
More information on El Niño/La Niña
Right now, portions of the western and central Pacific Ocean (near the equator) are still cool enough to be considered a weak La Niña. Areas further east and near the coast of South America have sea surface temperatures that are close to normal. The atmosphere above the tropical Pacific is also still displaying La Niña characteristics, mainly stronger than normal trade winds and reduced cloudiness over the central Pacific. Atmospheric conditions related to La Niña often persist for a couple months after sea surface temperatures return to neutral conditions, so expect La Niña to impact the climate of North America through June or July.
What will happen in the Pacific Ocean later in 2008 is much less certain. Some El Niño/La Niña prediction models show a continued decay of La Niña well into the summer, while others predict a return of La Niña in the fall of 2008. Multi-year La Niña's have happened in the past, most recently in 1998-2000. Even a switch to El Niño is possible later this fall, though not as likely as Neutral conditions or a return to La Niña. Keep in mind that these long range predictions are quite uncertain, especially at this time of year when the dynamics of the Pacific are not well understood.
Click here for our El Niño Discussion.
Wildfire Season
Widespread heavy rains across south Alabama, South Georgia, and Florida in March and early April eased wildfire concerns earlier this year. Since then, Florida and the Southeast have seen very little or no rainfall in over 30 days. Florida is now well into the spring dry season when brush and forests dry due to rising temperatures and normally light rainfall.
The drying of Florida and the Southeast has led to recent wildfire activity in Florida. Brush and forest fires in Volusia and Brevard counties destroyed nearly 40 homes and caused closures of I-95. A large brushfire in the Everglades near Miami has burned an excess of 30,000 acres and is still not contained. Keep in mind that wildfires are a normal fixture of Florida's climate in the late spring. The peninsula is generally fairly dry throughout the winter season and vegetation and fuels continue to dry through the spring until the summer convective rains set in. While the recent wildfires are alarming, they are really not unusual for this time of year. The summer rains effectively end the wildfire season in the state, but potential for large fires will continue until rains begin in earnest. The wildfire season rarely lasts past mid-June.