It’s St. Patrick’s Day (link) and everyone wants to be “wearin’ the green.” So, too, it seems, do weather maps. Florida’s weather maps from yesterday and today have far too much green on them. In weather circles, green is the initial code color for precipitation. As rainfall rates increase in intensity, yellows and reds are added to the greenish landscape.
Yesterday, heavy thunderstorms locked in across north Florida, deluging places like Tallahassee and Panama City with some three to six inches of rain (Fig. 1). Tallahassee reported thunderstorms in progress for nine consecutive hourly observations (Fig. 2).
Earlier in the day, a line of heavy thunderstorms developed across the Gulf Coast states and moved to the east and southeast. By the time it arrived over the Florida Panhandle, it had moved into a region in which upper level winds were parallel to the alignment of the line of storms (Fig. 3). This kept the thunderstorm area locked in place. The system basically sat over the same area for hours, as new thunderstorms replaced older, dissipating storms. The event is described as, “training,” because the storms moved along the line of the thunderstorms, much like railway cars move across a stationary railroad track.
Today, the line of thunderstroms is slowly moving to the southeast and was almost to the Tampa area at 10:00 a.m. E.D.T. (Fig. 4). The line is expected to continue moving southward, arriving into parts of southwest Florida by the dinner hour. With a very warm and humid air mass (dew points above 70 degrees) in place to the south of the line of thunderstorms, isolated air mass storms could spring up during the afternoon.
Some of the thunderstorms that move into the southern half of the Florida peninsula could reach strong to severe levels. In addition to the usual list of storm parameters (lightning and heavy rainfall), strong, gusty winds to 50 miles an hour or more could occur with some of the thunderstorms (Fig. 5). Due to the instability of the air mass and the high dew points, strong storms should continue into the overnight hours.
The front and its associated rain and thunderstorm area will be slow to clear south Florida (Fig. 6). It won’t be until Tuesday afternoon, before skies are expected to begin brightening; by Tuesday night, clear skies should become established across the area.
Don’t look for much in the way of cooling with this front. Daytime highs will continue to reach and top 80 degrees. Nighttime lows (thanks to lower dew points) will dip to the low and mid 60’s for a few days.
© 2014 H. Michael Mogil