Thanks go to Rob Molleda, the Warnings and Preparedness Meteorologist at the National Weather Service (NWS) Office in Miami, FL for preparing yet another annual summary of extreme and unusual weather events for our part of the world for 2012. You can read other recent annual summaries for our area at the following links:
The following is designed to clarify some of Molleda's entries and add a little extra meteorology into the discussion.
While the tropical Atlantic was very active in 2012 (19 named tropical systems, a few of which I still question their tropical mis-classification), Florida escaped landfalls from hurricanes and was only directly visited by two tropical storms (Beryl and Debby). Still, south Florida was affected by several storms that passed over Florida’s nearby offshore waters.
Event #1 – Tropical Storm Isaac brought torrential rainfall, and localized flooding, mainly to East Coast counties, even though Isaac passed closer to Naples. This was likely linked to an intense rain band that locked onto the East Coast due to coastal and ocean interactions.
Isaac’s passage by southwest Florida also ran contrary to many hurricane safety rules. As the storm approached, offshore winds pushed water away from the coast, resulting in very low water levels. Once the storm passed by and winds started blowing parallel to and onshore, water levels rose and quickly reclaimed beach areas. This pair of images (Fig. 1 and Fig. 2) was taken approximately 12 hours apart at Vanderbilt Beach, a western facing beach in North Naples, FL. The first image was taken on the evening of Sun., Aug. 26 and the second on the morning of Mon., Aug. 27.
High water continued along the west coast beaches for several days after Isaac’s closest passage due to the persistent winds and fetch over the Gulf of Mexico.
Event #2 – Hurricane Sandy brought large, long-period, swells to Florida’s southeast coast. The ensuing beach erosion and flooding was significant! Swells peaked Sat., Oct. 27th and Sun., Oct. 28th. Breaking waves were estimated to have ranged from 10 feet at the Miami-Dade County beaches to around 20 feet, perhaps even higher, at the Palm Beaches. Floodwaters swamped parts of coastal highway A1A in Fort Lauderdale, causing road closures that lasted for several days.
Event #3 – Tropical Storm Debby didn’t bring heavy rainfall or coastal flooding to our area, but her trek nearby in the Gulf of Mexico led to a two-day spate of twisters. Of 10 confirmed twisters observed over southern Florida on Sat., Jun. 23 and Sun., Jun. 24, eight occurred in a four-hour period during the late morning and early afternoon of Jun. 24. This was the greatest number of observed tornadoes in a single day in southern Florida since Hurricane Isbell in October 1964.
Most of the tornadoes were of the weak, short-lived variety. One, however, tracked for 16 miles as it moved to the north-northeast just east of Marco Island.
The most significant damage I saw involved the snapping of the top of a large Australian pine tree. This tree variety, not native to the local area, is highly susceptible to high winds. In this case, the tree fell onto a car, totally destroying the vehicle (Fig. 3). Two members of a family, who usually wait out the rain before heading into their home, opted to go inside on this day. Had they not done this, there would likely have been two fatalities. Sadly, however, the family had purchased automobile insurance online to save money and not added comprehensive coverage to their policy. As a result, the damage to their vehicle was not covered.
Based on this scenario, a good New Year’s resolution might be to double-check your auto and home owner’s insurance policies with an insurance professional.
Event #4 – It was a very wet year in south Florida, except for areas along or near coastal Collier County. Parts of Miami-Dade and Palm Beach counties received excessive, nearly record-breaking, annual rainfall; other places (such as West Palm Beach-PBI) logged record-breaking monthly rainfall. The 22.66 inches that fell at PBI in August topped records dating back to 1888.
Miami received 86.94 inches of rain in 2012 (2nd wettest since 1911). The NWS Miami Office on the Florida International University campus, recorded 99.42 inches. Juno Beach logged 101.79 inches. Typically, south Florida locales receive 45 to 60 inches of rainfall annually.
Naples, however, received a scant 37.93 inches (it’s seventh driest year since records began in 1942); Immokalee’s 37.23 inches was its fifth driest since records began in 1970. At both of these sites rainfall was deficient by nearly 14 inches (25%). Fort Myers, on the other hand, received 10 percent below average rainfall. Community lake levels at the start of the dry season across much of Naples and Collier County were much lower than average (Fig. 4).
Event #5– Baseball sized hail is not a common visitor to Florida and is even less likely to occur in south Florida. Yet, on Friday, June 15, intense afternoon thunderstorms produced hail the size of baseballs in two separate south Florida locales – the Coral Gables area and rural Hendry County.
According to the NWS, this was only the fifth time since 1955 that hail this size or larger was reported in south Florida.
Overall for the year, south Florida had more than its fair share of severe weather. There were 24 individual reports of large hail (one inch in diameter or greater) and 50 reports of thunderstorm winds of 58 mph or greater.
Looking ahead to 2013 … Although our area didn’t make the national headlines for the “top weather stories of 2012” – 28,400 hits (Fig. 5), or the “top 10 weather stories of 2012” – 82,900 hits, we still had our share of extreme and unusual weather events, as usual.
I predict we'll have a similar year in 2013!
© 2012 H. Michael Mogil