A shifting in the seasonal weather pattern began to appear over Florida during the month of October when the polar jet stream began to dip farther down into the south bringing multiple cold front passages in the month of October. The majority of these frontal passages were weak, and high pressure ridging aloft in some cases weakened the cold fronts before they could pass into the southern half of the state. Due to this fact, the majority of the state saw below-average rainfall amounts with the largest deficits seen over the Atlantic coastal areas. Above-average rainfall was primarily seen in the Florida panhandle where the cold fronts had the most strength providing the greatest lifting for rainfall; the largest surpluses for rainfall in October were seen in the FFS District-1 area of the western panhandle. During October, the majority of the state saw above-average to slightly above-average temperatures excluding the southern parts of the state which saw near-average to average temperatures.
Zonal-westerly to southwesterly jet-stream flow kept Florida relatively moist this November with many areas of the state experiencing above-average rainfall. This type of jet stream pattern over Florida is synonymous with an El Niño event, such as what is currently being experienced. Like October, multiple weak cold fronts made their way through the state, usually dissipating by the time they reached south Florida. Moister conditions caused many parts of the state to see wetter, more-unstable conditions than October, as well as humid conditions in the lower atmosphere behind cold front boundaries. The Florida panhandle and Big Bend areas saw the greatest rainfall surpluses from widespread rainfall from frontal passages. The Florida peninsula, especially the southern area, saw the majority of their surplus rainfall from a combination of frontal influences as well as localized boundaries such as sea breezes. In November, above-average temperatures were seen throughout the state.
Despite a similar jet stream pattern to November over the state in December, below-average rainfall has been seen in the majority of the state. The only areas that have seen above average rainfall has been in FFS Region 4 with the greatest surpluses seen in eastern areas of FFS Districts 16 and 18 due to the low-level convergence from the sea breeze and remnant frontal boundaries as well as unseasonably warm, moist conditions which has provided the state with above-average temperatures so far this December.
Long-Range Weather Outlook
Looking ahead at this coming January through March, the NOAA Climate Prediction Center (CPC) is currently forecasting below-average temperatures for the entire state. This below-average temperature outlook for the next 3 months for Florida is likely a response to the El Niño conditions currently occurring in the equatorial Pacific. Climate models are suggesting that average to above-average temperatures will occur in January while average to below-average temperatures have the greatest chance of occurring in February and March.
Additionally, the CPC is forecasting Florida to have a very good chance for above-average precipitation totals over the next three months, with the greatest chances occurring in northeast Florida and over the Florida peninsula. This rainfall outlook for Florida reflects the current El Niño event as well. Looking at the climate outlooks month by month, it appears that Florida is expected to receive above-average rainfall for each month. The majority of the rainfall events this winter will most likely come from surface low pressure systems in the southeast which are common during the winter months of an El Niño event due to the eastward shifting of the jet stream.
The current El Niño event in the equatorial Pacific is strong and is forecasted to remain strong over the next three months, which is reflected in the temperature and precipitation outlooks for Florida. Currently, SST anomalies greater than 2°C are impacting the majority of the eastern and central equatorial Pacific. The peak of these anomalies is forecasted to occur over the next month or so, before a trend downward toward El Niño-neutral conditions is expected in the late spring to early summer of 2016.
Summary and Fire Potential Outlook
Overall, the state of Florida has seen a moderately wet November with humid conditions and above-average rainfall which has helped the state experience relatively low statewide KBDI averages over the last several weeks. These wet conditions are expected to continue over the next three months due to the above-average precipitation forecast given by the CPC. This fact, along with a below-average temperature outlook over the next three months, is evidence of the atmosphere responding to the strong El Niño conditions in the equatorial Pacific that are expected to continue over the next few months.
These conditions in the Pacific are expected to continue up until late spring/early summer at which point conditions will become primarily neutral. Rainfall events over the southeast U.S. during an El Niño year usually stem from surface low pressure systems that are influenced by the eastward shift of the jet stream. These low pressure systems will likely be the driving force for the above-average rainfall that is expected to occur over the next three months. Below-average temperatures and above-average rainfall could likely decrease the number of days for optimal prescribed burning conditions, but will also lessen the chance of any severe wildfire activity.
The next seasonal outlook will be the first week in April 2016.
Drought Outlook (NOAA)