Drier Air or Wetter Weekend?
It has looked like summer across much of Florida this week, but that is all about to come to an end. I’ll get to that in a bit, but first I want to take a look at the pattern that we have been under for a little more than a week state wide. Interesting picture below showing the imbalance of rainfall over the last seven days. The image shows the percent of ‘normal’ rainfall over the last week with the warm colors showing less than normal and the cooler colors showing more rainfall than normal. This does not include today’s rainfall, but it does show that high pressure has been anchored down to our south and the beginning of the sea breeze in north Florida. Since high pressure remains in place to the south (through tonight), clockwise winds have been pushing storms in central and south Florida toward the east coast over the last week. In north Florida, the sea breeze has kept the severe weather away from the coast line. After the sea breeze pushes through an area, the area becomes too stable to support many showers and thunderstorms, and thus blocking any strong to severe weather from the coast line. You can see this effect in north Florida as the thin red line of below normal rainfall from Cedar Key to Apalachicola and almost to Pensacola Beach.
Shifting to the upcoming weather, and a cold front is on the way!…well, more like a dry front. The front is currently located from Perry to Jacksonville, and will be pushing into central Florida before sunrise and into south Florida by late afternoon. This isn’t really the most welcome weather feature in Florida since much of the state is in a drought, but a few showers can be expected overnight along the west coast and in south Florida tomorrow afternoon. We might be able to wring out a 30% chance around Tampa Bay and up to 40% along Alligator Alley and South Florida.
The unfortunate side effect of this wind switch (It’s hard to call this a cold front!) is the dry air that it will bring down the interior of the state, effectively slowing the start of the rainy season. The rainy season generally begins in late May to early June from south to north, and varies quite a bit from year to year. I do think that the rainy season will begin on time or just ahead of schedule this year because of all of the heat in place.
The ‘front’ is already pushing drier air into the southeastern US seen in black and darker greens in the image below, with dew points dropping into the 40s and 50s. The dew point is the most accurate measure of the amount of juice in the air, and the lower it is the drier it is outside. Dew points could drop into the 40s in north FL, and into the 50s across the I-4 corridor. This will limit shower activity around most of the state to less than 20% for the early parts of the weekend. This dry air will not stick around for long in May, and rain chances will be back up to 30-50% by early next week.
This is a reminder that hurricane season in the north Atlantic begins in just three weeks! Get your supply kits ready once again, including food and water for every person in your family including pets for at least 3 days, clothes for everyone for a week, and something to keep you occupied when the power and internet goes out.
On April 27th, I graduated with a Bachelor’s degree from the Florida State University in meteorology. This makes me an official Meteorologist after five years of being in school. I wanted to thank the people at Florida State and at St. Petersburg College as well as my new families in Phi Theta Kappa and the American Meteorological Society/National Weather Association for everything that I could not have done without your support and for everything that you will do for students like me in the future!