Visualization of surface winds, with reds indicating stronger winds. The approximate center of the low pressure is marked with a red “L”. (earth.nullschool.net)

A tropical disturbance we’ve been watching closely for the past five days in the Caribbean has strengthened and has formed into Tropical Depression Three — the third tropical cyclone of the 2016 season.

It is now centered over the northern tip of the Yucatan Peninsula, poised to enter the southern Gulf of Mexico on Sunday afternoon. If conditions remain favorable, it could strengthen into Tropical Storm Colin, especially as it crosses over into the warm waters of the Gulf.

Colin would be the earliest third tropical storm on record by a full week if it forms on Sunday.


Visible satellite image from 9 a.m. EDT today. The center of the low pressure is located west of the bright, high cloud tops. (NASA)

Like Bonnie, global forecast models picked up on this potential storm about 10 days ago, impressively. Models are also in excellent agreement on the future track of this system — northward for another day, then a trough over the southeast U.S. picks it up and steers it to the northeast toward Florida later on Monday.


(NOAA)

Thanks to the hefty wind shear, the system is not expected to strengthen into a hurricane. Even so, this storm shouldn’t be dismissed. Even minor storm surges generated by onshore winds can flood low-lying areas during normal astronomical high tides. Minor storm surge could be a concern from Cedar Key down to the Tampa Bay area.

The biggest impact will be very heavy rain over a period of a few days. The latest 5-day rainfall forecast shows a large portion of the state receiving at least 2 inches, and central Florida could locally see much higher amounts.


Rainfall forecast from Sunday morning through Friday morning. (NOAA)

If we take a look through the records, this area of development and track is fairly typical. The map below shows tracks of all tropical storms and hurricanes that hit Florida during June. They usually do form in the western Caribbean and head north then northeast to reach the state.


Tracks of all tropical storms and hurricanes that hit Florida during June.