Tropical Storms Humberto, Imelda Ahead: What It Could Mean For US, Bahamas

Humberto Forms: Coastal Threats For US, Bermuda

Tropical Storm Humberto has formed in the Central Atlantic and Imelda is likely to follow soon. Humberto is likely to remain away from the mainland United States, but the interest area we are watching for Tropical Storm Imelda could pose a larger threat to parts of the Southeast U.S., the Bahamas and Bermuda as the Atlantic Basin’s active period continues following Hurricane Gabrielle.

There is still considerable uncertainty as to the details of how this will all shake out into next week, so please check back with us at weather.com for important updates in the days ahead as the forecast gradually becomes clearer.

Here’s our latest thinking, including a potentially weird wild card to the forecast.

Newly-formed Tropical Storm Humberto To Near Bermuda

Formerly-named Invest 93L is several hundred miles east of the Leeward Islands.

Models suggest that it will strengthen into a Category 2 or 3 hurricane that could be of some threat to Bermuda early next week, but is unlikely to be a U.S. threat.

Bigger Concern For The U.S. East Coast

A tropical wave currently moving through the northeast Caribbean — designated as Invest 94L — will bring showers with locally heavy rain to Puerto Rico and the Virgin Islands through early Friday, then Hispaniola, eastern Cuba and the Bahamas.

(MORE: What An ‘Invest’ Means In Hurricane Season)

From here, the system will head westward across the Dominican Republic, Haiti and the Turks and Caicos in the next couple of days.

This system, which would be named Imelda, is most likely to form by this weekend when it’s somewhere near the Bahamas.

There is a lot of uncertainty in the forecast for this system.

Some computer forecast models pull this system north near or over and western Bahamas and off the Southeast U.S. coast from Florida to North Carolina early next week. It may either stall offshore for a few days or landfall some time Monday – Tuesday. It may either be a tropical storm or hurricane at that time.

Hurricane Hunter reconnaissance aircraft missions around this system are beginning this afternoon, according to the NHC. This first flight is to determine how favorable the environment is around the system and what steering patterns are in place to narrow this forecast down.

Most of the models eventually shove this system eastward into the Atlantic by mid-late next week, but that eastward shove could propel it toward Bermuda, meaning it could be the second system to affect Bermuda in just a few days’ time next week.

Even if this system doesn’t ever make a landfall in the U.S., days of onshore winds are likely to generate dangerous high surf, rip currents and at least some coastal flooding up and down the Eastern Seaboard from Florida to New England next week.

All interests in the Bahamas, the U.S. East Coast (especially from Florida to North Carolina) and Bermuda should closely monitor the progress of this forecast.

As usual for late September, there is plenty of deep, warm ocean water that could fuel tropical development in this area, as was the case with Hurricane Gabrielle.

A Weird Possibility

One other outcome suggested by some computer models is that both systems could be close enough to each other to do a kind of circular dance, what meteorologists call the Fujiwhara effect.

Sometimes the larger system can grab hold of the smaller one and absorb it. Other times, both systems can creep closer and spin around each other before going on their own paths.

This happened in recent years most often in the Pacific Basin, including last year with tropical storms Emilia and Fabio.

We’ll keep an eye on this possibility in the coming days and spell out what it could mean for you if this “dance” becomes imminent.

Check back with us at weather.com for the latest on these systems.