I’ll Follow the Sun … to Tampa

By April, you are likely to be thinking that it’s been a long cold lonely winter. If you’ve booked your ticket to ride to our 2014 AAG annual meeting in Tampa, then a good day sunshine may very well be on the horizon. Florida’s peninsular shape, concave and convex coastal segments and location between the Gulf of Mexico and the North Atlantic Ocean all play an essential part in the development of the state’s weather (Stowers and Tabb 1987). Spanning latitudes 25-30° N, most of the state experiences humid subtropical conditions according to the climate classification developed by Köppen. When the rain comes, they run and hide their heads from an average of 46.3 inches in Tampa (Hillsborough County) and 50.8 inches in St. Petersburg (Pinellas County) each year (NWS Data). For two months of the year, the average high temperature in Tampa is above 90°F with relative humidity above 50 percent, yet Sunshine State weather in April tends to feel fine with an average high at just 81° F.

However, tangerine trees and marmalade skies can give way to damaging winds and heavy rains, leaving many with a need to fix the holes where the rain gets in. Florida is not a stranger to thunderstorms. In fact, lightning occurs so frequently within Florida that the state is considered the lightning capital of the United States with over fifty strikes per square mile per year (Mogil and Seaman 2008). Cloud-to-ground lightning often streams helter skelter across the landscape as the state’s highest flash densities occur in West-Central Florida around Tampa Bay. This is due to the collision of sea breeze boundaries in this area of the state, especially during June-August. Spectacular offshore lightning displays at night can be triggered by land breezes. So come to Florida and join the local hockey fans who enjoy a fantastic “Lightning” display.

Tornadoes have occurred in every state. However, some may be surprised to learn that Florida was ranked third in average annual tornadoes per state 1991-2010 according to data from the National Climatic Data Center (NCDC). Florida had an average of 66 tornadoes reported annually during that period, including 105 in 2004 alone. April 2014 marks 49 years since an F4 tornado moved across Pinellas and Hillsborough Counties and continued across the peninsula causing upwards of 3300 injuries with 11 deaths. It is the only F4 tornado occurring in Florida since 1950 according to data from the Storm Prediction Center. Fortunately, no other April tornadoes have caused the wind to be high within Hillsborough County where our meeting will be held. Water spouts are also a common occurrence along Florida’s coastline. A 15-year study by Golden (1977) found that the Florida Keys experienced the greatest frequency of water spouts from Texas to Maine. But when you talk about destruction, Tampa Bay had the highest number of damaging cases.

The severe weather phenomenon most often associated with Florida is the hurricane. While Tampa has not experienced a landfall in many years, the state of Florida has not been so fortunate. Florida experiences twice as many landfalling hurricanes as the next prevalent state, Texas. After using a GIS to plot the tracks of all tropical cyclone during 1851-2011 (Figure 1), it can be seen that 269 have crossed the boundary of Florida, yielding an average of 1.67 landfalls per year and many a wild and windy night. Fortunately for AAG attendees, no Florida landfalls have occurred during April. Unlike some other national events held in Tampa e.g. the 2012 RNC, the AAG invites its members to Tampa before hurricane season starts!

When considering the impacts of these various weather phenomena, one must also consider the number of people who have come together to live in the Tampa Bay area. Population growth from 1950 – 2010 was 390% for Hillsborough County and 475% for Pinellas County. Neighboring Polk and Pasco Counties experienced growth of 385% and 2165%, respectively under their blue suburban skies. The implications of this growth are staggering in terms of the number of people left to make ends meet and millions of dollars involved if disastrous weather should strike the Tampa Bay area. Given the shallow bathymetry of the bay, the infrastructure built along and near its shores, and the high population density in the area, the costs of Hurricanes Andrew, Katrina, or Sandy could easily be surpassed if a similar storm hit Tampa.

Yet before the arrival of hot weather and hurricanes, April is a great month to be outdoors and follow the sun in Tampa. According to the NCDC, the average high and low temperatures for the week of the AAG conference approximate 80° and 61° F, making for a fab forecast. Unfortunately for those who like to watch endless rain pouring into a paper cup, April is the second driest month receiving only 2.03 inches of rainfall on average. If you do wear a raincoat, you may be standing solo in the sun as April is tied with May as the sunniest month of the year, with 75% of possible sunshine occurring. Sun, sun, sun, here it comes! With sunshine at its highest, temperatures at their most pleasant, and severe weather occurrences at their lowest, the weather is sure to please please you during the 2014 AAG annual meeting in Tampa. We hope you will enjoy the show.

Dr. Jennifer Collins
University of South Florida