Prepared by David F. Zierden and Melissa Griffin
Florida Climate Center
The Florida State University
Tallahassee, FL

Winter cold returns in January after a warm December. The roller-coaster ride of unseasonably warm periods followed by chilling cold temperatures continued over Florida this past month, which is typical of the winter season in this state. Temperatures during the first two weeks of January ran generally normal to above normal, with several days of afternoon highs in the high 70's to low 80's during the first week. No significant cold fronts passed through during this time. Beginning on January 14, a large-scale pattern set up with high pressure ridging in the western United States and deep troughing over the eastern U. S. This pattern brought a series of cold fronts and arctic air masses to the area that kept temperatures well below normal over the next 10-12 days.

The coldest temperatures of the year occurred during this time coinciding with an unusually strong arctic air mass that settled over the region on January 20-23. Strong northerly winds on the night of January 20 brought freezing temperatures as far south as Fort Pierce and Okeechobee that night and early the next morning. Florida Automated Weather Network (FAWN) stations at Immokalee, Palmdale, and Belle Glade recorded temperatures of 30, 31, and 32 degrees respectively. On the next night (January 21-22), the very dry high pressure center settled over the state calming winds and setting the stage for a classic radiational freeze event. Radiational freezes can be very damaging, as temperatures drop quickly after sunset leading to extended periods of freezing temperatures. This evening/early morning brought the coldest temperatures since 1997 to some parts of the state and since 2001 to others. Temperatures in the teens to low 20's covered most of inland Florida as far south as Polk County. Elsewhere in south Florida, freezing temperatures were recorded across many locations and as far south as Dade County, with the coldest pockets occurring in lower elevations and over sandy soils. Curiously, no official records for daily low temperatures were broken during this event.

Warm temperatures returned again in the last week of January, with several locations in central and south Florida recording record daytime high temperatures on January 29th and 30th.

Table 1: January average temperatures and departures from normal for selected cities (degrees F.).

January generally drier than normal. Generally drier than normal conditions persisted across Florida in January. Rainfall deficits for the month ranged from over 4 inches in Tallahassee to around 1.5 inches in south Florida. The driest areas right now are around the southeast coast of Florida, where rainfall totals for the month of January were less than half an inch. The West Palm Beach area had perhaps the driest January on record, only record 0.11 inches of rainfall. The only significant widespread rainfall event was on January 29-30, where much of central and north Florida saw 1-2 inches prior to the passage of a cold front.

Table 2: January precipitation totals and departures from normal for selected cities (inches).

Other weather and climate impacts. In a broader scope, it appears that the tropical Pacific Ocean has fallen back into the La Ni%ntilde;a phase (colder than normal waters along the equator in the eastern and central Pacific). La Ni%ntilde;a is known to bring warm and dry winters to Florida and the Southeast and is likely responsible for the relatively dry weather thus far this winter. On the other hand, temperature patterns have not been typical of La Ni%ntilde;a recently. The dramatic swings between warm and cold, along with the outbreaks of cold arctic air are more reminiscent of winters during the neutral phase.

Florida was relatively free of any severe weather in the past month.

Impacts on agriculture and forestry. The freezing temperatures of January 21st and 22nd have had the largest impact on agriculture this month. The citrus regions relied heavily on the use of irrigation for cold protection of fruit and vegetation. Strawberry growers around Plant City and Dover also tried to protect fruit and plants with irrigation and coverings, but some damage was reported to fruits and to blooms. Some fields may lose a harvest cycle due to flower damage. Other vegetable growers reported significant damage, especially to sensitive crops like bell peppers and tomatoes. The tropical fish industry, centered around the Tampa and Lakeland area, suffered losses up to 20% to 30% in uncovered ponds.

The dry weather superimposed on the peninsula's typical dry winter season has forests and fuels dangerously dry for wildfire potential. The Florida Division of Forestry reports that portions of central and south Florida have Keetch-Byram Drought Index (KBDI) values over 700 corresponding to a severe threat. Also, recent freezes have browned up smaller fuels and vegetation which will only add to the threat.

Figure 1: KBDI values from radar-derived precipitation estimates (Courtesy of FL DOF).

Prepared by David F. Zierden and Melissa Griffin
Florida Climate Center
The Florida State University
Tallahassee, FL

December warms after a cold fall season. After a cold beginning to the fall season, where temperatures from late October through November averaged around 5 degrees below normal, a warm pattern set in for the month of December. Average temperatures ranged from 1 to 2 degrees above normal in central and south Florida to 3-4 degrees above normal over north Florida. The coldest temperatures of the month occurred after a fairly vigorous cold front passage on December 2nd and 3rd, with freezing temperatures reported as far south as Ocala on the morning of the 2nd. The second half of December was quite warm for the entire state with only one notable cold front passage on or around December 22. With the exception of this date, almost all other days in the second half of December have seen daily temperatures warmer than normal, up to 10 to 12 degrees warmer in most cases. A record low temperature for the date was set at Sarasota-Bradenton with a recording of 39 degrees on the morning of December 3. Numerous record high temperatures were set or tied across north Florida between December 19th and 25th.

Table 1: December average temperatures and departures from normal for selected cities (degrees F.).

December generally drier than normal. Nearly all locations in Florida recorded below normal rainfall during the month of December. Departures from normal ranged from 1 to 3 inches for the month. The state experienced one major rain event on December 10th and 11th from a low pressure system that developed in the northern Gulf of Mexico and moved slowly inland across the Panhandle. Precipitation totals from this system were heaviest at Okaloosa County where totals from 4 to 6 inches were reported and in Jackson and Holmes counties, where totals reached 6 to 8 inches. The remainder of the state generally saw totals between half and inch to one inch. One daily record for rainfall was set at Fort Myers with 1.83 inches accumulating on December 11.

Table 2: December precipitation totals and departures from normal for selected cities (inches).

Figure 1: Radar-derived rainfall totals for the month of December (inches)

Other weather and climate impacts. Much of December was free from any severe or high impact weather events, with a few minor exceptions. The heavy rain event mentioned above did result is some minor flooding of small rivers and streams in areas around Tallahassee and the western Panhandle. The same system was also responsible for scattered reports of wind damage across north Florida and Pinellas County. Otherwise, the freezing temperatures seen across north Florida on December 2nd and 3rd were not overly damaging and well within the range of expected weather for this time of year.

In a broader scope, it appears that the tropical Pacific Ocean has fallen back into the La Niña phase (colder than normal waters along the equator in the eastern and central Pacific). La Niña is known to bring warm and dry winters to Florida and the Southeast and is likely responsible for the warming (and drier) trend seen in the second half of the month.

Impacts on agriculture. The unseasonably warm second half of December has slowed chill accumulations over much of the area. Chill accumulation over the winter is important to flowering fruit crops such as blueberries, peaches, and strawberries and promotes proper fruit setting. Chill accumulation was ahead of normal during the colder period of late October through the first week of December, but has slowed considerably during the recent warm spell. The warmer temperatures have enhanced development of other crops, namely winter vegetables and winter wheat. Winter forages for cattle were doing well with the warm temperatures in areas of north Florida that have received adequate rain. Dry and warm conditions in the citrus belt have producers irrigating more.

Prepared by Melissa Griffin, Preston Leftwich, and David F. Zierden
Florida Climate Center
The Florida State University
Tallahassee, FL

Average temperatures were mainly above normal in January. Average temperatures were above normal for most of the state, with the exception of Orlando (Table 1). Departures from normal ranged from -0.8°F at Orlando to a staggering 6.8°F at Pensacola. The warmer temperatures have the public and some media outlets calling this "The Year Without a Winter." Unlike the Januarys of 2010 and 2011, there was very little cold air that made it into Florida. There were two strong cold fronts that passed through the state at the beginning of the month, leading to record low temperatures being tied and broken on the 3rd and 4th (Appendix). For the rest of the month, most of the state experienced warmer than normal temperatures that are typically reported with La Niña conditions, and various record high temperatures were tied and broken at the end of the month (Appendix).

Table 1: January average temperatures and departures from normal (° F) for selected cities.

Rainfall totals below normal statewide in January. Rainfall totals were below normal statewide in January (Table 2). North Florida and the Panhandle had 2 inches or more below typical rainfall amounts for the month, which compounded the drought problems that have been lingering since October 2010. The month was the driest on record at Orlando and was the 4th driest on record at Jacksonville. Though rainfall was scarce across the state, there were a few daily precipitation records that were broken during January (Table 3). Areal patterns of monthly rainfall relative to normal are depicted in Figure 1.

Table 2: January precipitation totals and departures from normal (inches) for selected cities.

Table 3: Daily rainfall records (inches) broken during January (compiled from NOAA, NWS).

Figure 1: A graphical depiction of the monthly rainfall departure from normal (inches) for January is given in the figure below (courtesy of NOAA, NWS).

La Niña continued during January. La Niña conditions continue to be present across the equatorial Pacific, with sea surface temperatures (SST) at least 0.5°C below average for the region. The atmospheric circulation anomalies and winds are consistent with La Nintilde;a. The current La Nintilde;a is forecasted to continue through the winter of 2011/2012 into the spring, with the possibility of a return to neutral conditions by the summer. The Climate Prediction Center continues to predict warmer than normal temperatures and below normal precipitation through May.

Hazardous weather. A variety of hazardous weather events took place in January. Portions of northern Florida were impacted by high winds from a passing cold front at the beginning of the month. Dense fog was reported in the Panhandle on the 7th and 8th, with visibilities below 0.25 miles. Another passing cold front brought high winds to most of the state with wind gusts of at least 40 mph reported from locations near Pensacola, Jacksonville, and Tampa; while a 58 mph wind gust was recorded near Key West. Storm damage was reported with a vigorous squall line that moved through portions of the Panhandle on the 26th. Reports of trees being felled were received from both Walton and Leon Counties. An EF-1 tornado passed through Port Charlotte on the 27th, damaging a few homes and an apartment complex along its 0.75 mile path.

January also marks the beginning of the wildfire season in Florida, though there have been fires actively burning since fall 2011. Smoke from the Olive Fire, which has burned about 1,000 acres in Putnam County since Thanksgiving 2011, combined with fog to cause visibility problems and accidents at the beginning of the month. Towards the end of the month, the Payne's Prairie wildfire reduced visibilities along portions of US 441 and Interstate 75 and may have been the cause of a deadly accident that took 10 lives in the early morning hours of the 29th. On the 30th, another wildfire in Baker County was reported, causing travel headaches for motorists travelling on Interstate 10 just west of Jacksonville.

Agricultural and other impacts. Freezing temperatures on the 4th-5th caused damage to crops in the interior portions of the state. Fruit and vegetable growers reported freeze damage to snap beans and flowering squash plants. Green beans in Palm Beach County suffered significant damage, with about half of the crop destroyed. Another cold snap the following week led to the use of sprinklers in order to protect the strawberry crop, while the sugarcane crop was assessed for damage. The continued dryness across the state compounded the effects of existing low soil moisture levels.

At the beginning of January, about 91% of the state had designated drought conditions; by the end of the month, every part of the state was experiencing drought, with about 86% of the state in moderate drought. The Panhandle continues to be plagued with extreme drought, with some of the areas that had seen improvements in December drying out once again. Manatee, Sarasota, De Soto, and Hardee Counties went from abnormally dry to severe drought during January. Continued La Niña conditions through the remainder of winter and into spring will mean decreased precipitation, and water restrictions remain in place in South Florida (the water level of Lake Okeechobee is now 13.31 ft) and restrictions in other areas could go into effect.

Figure 2: Drought conditions in Florida as of January 24, 2012 (courtesy of U.S. Drought Monitor).

Appendix: Daily maximum and minimum temperature records (° F) tied or broken during January (compiled from NOAA, NWS).

Prepared by Melissa Griffin, Preston Leftwich, and David F. Zierden
Florida Climate Center
The Florida State University
Tallahassee, FL

Average temperatures were well above normal in February. Average temperatures were well above normal across the entire state (Table 1). Departures from normal ranged from 2.6˚F at Miami to 4.5˚F at Pensacola. There was only one strong cold front that passed through the state around the middle of the month, leading to record low temperatures being tied and broken on the 12th and 13th (Appendix). For the rest of the month, most of the state experienced warmer than normal temperatures, which are typically reported with La Niña conditions. Various record high temperatures were tied and broken at the end of the month (Appendix). Some of the record high temperatures were in the upper 80s, with Melbourne reporting a record high of 90˚F on the 24th.

Table 1: February average temperatures and departures from normal (° F) for selected cities.

Rainfall totals varied statewide in February. Rainfall totals varied statewide in February (Table 2). Most stations saw below normal rainfall, while some stations saw slightly above normal rainfall for the month. Portions of Holmes, Jackson and Washington counties in the Panhandle saw rainfall totals approximately 3.00” above normal. Heavy rains impacted The Keys and coastal Dade County at the beginning of the month, and the middle of the month brought heavy rains to portions of the Panhandle (Table 3). Areal patterns of monthly rainfall relative to normal are depicted in Figure 1.

Table 2: February precipitation totals and departures from normal (inches) for selected cities.

Table 3: Daily rainfall records (inches) broken during February (compiled from NOAA, NWS).

Figure 1: A graphical depiction of the monthly rainfall departure from normal (inches) for February is given in the figure below (courtesy of NOAA, NWS).

La Niña losing steam in the Pacific Ocean. La Niña conditions have peaked across the equatorial Pacific. Equatorial sea surface temperatures (SST) were at least 0.5˚C below average in the central Pacific, but have warmed considerably across the east-central and eastern Pacific Ocean in the last couple of weeks. The atmospheric circulation anomalies and winds are still consistent with La Niña, but the La Niña is expected to transition to neutral conditions during March-May 2012. The Climate Prediction Center continues to predict warmer than normal temperatures and below normal precipitation through May.

Hazardous weather. A few significant weather events took place in the month of February. On February 18 and 19, a line of strong thunderstorms pushed through the Panhandle and portions of North Florida. Heavy rain was reported in many locations, with some storm spotters across the Panhandle reporting up to 7.00” in localized areas and flood conditions in portions of Holmes and Walton Counties. High winds accompanied the line of storms with wind gusts ranging from 45 mph to 60 mph from a variety of locales, such as Jacksonville, Daytona Beach, Gainesville, Orlando and DeFuniak Springs, while trees were reported down in Marianna and Flagler Beach. A rapidly moving cold front brought high winds to central Florida on the 22nd, with wind gusts up to 50 mph reported in Orlando and Tampa. Another cold front moved through Florida on the 24th, causing downed trees in Tallahassee and Marianna, while the Jacksonville International Airport reported a 40 mph wind gusts as the front passed.

There were a few fires reported during February. A small wildfire in Pasco County forced some homes to be evacuated on the 8th. On the 11th, a wildfire in Hillsborough County caused parts of I-75 to be closed due to low visibility caused by smoke. The No-Go Fire in Brevard County grew to engulf 1800 acres of the St. John’s Wildlife Refuge on the 23rd.

Agricultural and other impacts. Freezing temperatures on the 12th and 13th caused damage to crops in the interior portions of the state. But for the most part, the above average temperatures across the state have aided the development of winter wheat. The episodes of windy conditions throughout the month have helped to deplete topsoil moisture. Fruit orchards and vegetable fields have been frequently irrigated to combat the drought conditions, while trees were also being hedged and topped. Statewide, producers were busy preparing fields for spring planting.

Since the beginning of February, the drought conditions have gotten worse in some areas. The area of extreme drought expanded from just a few counties in the Panhandle to include most of North Florida and the Big Bend region. At one point during February, the National Drought Monitor had Gadsden, Leon, Jackson, Jefferson, Washington, and Calhoun counties under D4 drought designation, signifying an exceptional drought. Rains during the 18th and 19th eased those areas back into an extreme drought classification. The rest of the state has seen below normal precipitation as well, leading to the expansion of severe drought along the Sun and Space Coasts. Even though La Niña is forecasted to transition to neutral conditions during the next three months, current predictions still have most of the southeastern U.S. experiencing warmer than normal temperatures and below normal precipitation.

Figure 2: Drought conditions in Florida as of February 28, 2012 (courtesy of U.S. Drought Monitor).

Appendix: Daily maximum and minimum temperature records (° F) tied or broken during February (compiled from NOAA, NWS).