Tammy Turns North but Will it Head Back South?

Tammy’s future track up in the air as flooding persists today across parts of the Leeward Islands

Monday morning satellite of Hurricane Tammy northeast of Puerto Rico. Credit: NOAA

After skirting the Lesser Antilles of the eastern Caribbean over the weekend – passing over Barbuda as an 85 mph Category 1 hurricane late Saturday upon exiting the islands – Tammy continues to pull away to the north, maintaining its hurricane status over the western Atlantic.

Tammy’s trailing tail of training rains caused dangerous flooding across parts of the Lesser Antilles beginning on Friday, from Barbados in the south to Guadeloupe in the north during the day Saturday. Because the compact center of Tammy mostly grazed the islands to the east, winds on land generally stayed below hurricane strength (74+ mph), except in Barbuda which took a direct hit from Tammy, reporting maximum sustained winds as high as 90 mph (unofficially) Saturday evening.

Though the center of Tammy – now situated about 200 miles north of the Caribbean – is moving away from the islands, heavy rains and flooding will persist through today in its wake for the northern Leeward Islands. The Category 1 hurricane is forecast to have a window for strengthening over the next day or two over the open Atlantic before conditions become more hostile by later this week.

What’s next for Tammy?

The bigger question is what happens with Tammy this weekend and early next week. Some of our computer models show the storm being picked up by a mid-Atlantic cold front and getting ushered northeastward and out to sea. Other model scenarios suggest Tammy gets left behind by the front and retrogrades back westward toward Florida or the mainland U.S. as a notably weaker low-pressure system into the weekend.

Forecast tracks for Tammy through Saturday evening (October 28, 2023) from the European ensemble modeling system. Stronger tracks are indicated by warmer colors (yellow/orange/red), with weaker tracks shown in cooler colors (blues). Forecast models suggest large uncertainty in the long-range track of Tammy or its remnants, with stronger scenarios east and weaker scenarios farther west. Credit: Weathernerds.org

Over 1500 miles exists between possible tracks for Tammy over the next 5 to 7 days, so it’ll take a little time to shake out what happens beyond mid-week. Regardless for South Florida, in the event of a southwestward dive, Tammy or its non-tropical remnants would be accompanied by a potent upper-level low that would both act to impart wind shear over the low-pressure area and inject cooler and drier air from above. The combination would mean a much weaker system if the southern scenarios come to fruition. We’ll monitor the trends, but for now, we don’t anticipate a significant threat even if the ghost of Tammy makes an appearance farther south.

One indirect effect Tammy will have on our weather this week will be strong onshore winds, as South Florida gets sandwiched between Tammy’s low pressure to the east and building high pressure to our north. The brisk east and northeast wind will persist through the workweek, likely leading to a high risk of rip currents from tomorrow onward along Florida’s east coast beaches. Winds should begin to relax into the weekend.

Elsewhere in the Atlantic this week

An area of low pressure tucked away in the far southwestern Caribbean – designated Invest 95L – could become a short-lived tropical depression over the next 24 hours. 95L or what forms from it will be moving quickly inland over Nicaragua by Tuesday so significant development isn’t expected. The main threat regardless will be heavy rainfall and the potential for flooding this week across areas of Central America.