Potential For Tropical Storm Imelda Increases As Tropical Storm Humberto Strives For Hurricane Strength
Humberto could become the season's next major hurricane, but the interest area set to become Imelda could be a threat to the Bahamas and U.S. Here's what you need to know in our latest forecast update.
Humberto To Become Hurricane
Tropical Storm Humberto is forecast to become a major hurricane in the central Atlantic, but the next system expected to develop, which would be named Imelda, may become a larger threat to parts of the Southeast U.S. and Bahamas as the Atlantic hurricane season shifts into a higher gear following Hurricane Gabrielle.
There is still a lot of 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 strange wild card from this pair of systems.
Tropical Storm Humberto Will Become A HurricaneTropical Storm Humberto is located about several hundred miles northeast of the Leeward Islands. It's moving toward the northwest and is no threat to neither the Leeward Islands nor the rest of the Caribbean.
The storm is gaining strength and is forecast to become the season's third hurricane this weekend. Humberto could be of some threat to Bermuda early next week, but is unlikely to be a direct U.S. threat.
 Projected Path
Future 'Imelda' An Increasing Concern For The U.S.A tropical wave currently in the Turks and Caicos Islands — designated as Invest 94L — will continue wringing out showers with locally heavy rain and gusty winds to the Dominican Republic, Haiti and the Turks and Caicos Islands. This activity will then spread to eastern Cuba and the Bahamas this weekend.
(MORE: What An 'Invest' Means In Hurricane Season)
This tropical wave brought widespread rainfall of 1 to 4 inches across Puerto Rico, with the heaviest totals being reported across the southern parts of the territory. No surprise that this heavy rainfall brought some flood and landslide reports across Puerto Rico highways, with one car being washed out with people still inside.
It's this weekend, when this system is near the Bahamas, that we expect it to develop into Tropical Storm Imelda.
 NHC Development Chance
Most computer forecast models draw Imelda northward through or near the Bahamas through Sunday.
Beyond that, there appear to be two main scenarios emerging:
1. Imelda could continue moving north and move into either Georgia or the Carolinas as either a tropical storm or hurricane early next week.
2. Imelda could stall off the Southeast coast for a day or two early next week before either being pulled east away from the coast, possibly toward Bermuda, or being absorbed by Humberto.
As of Thursday evening, models have started to trend towards the Southeast by mid-week next week.
 Spaghetti Models
As usual for late September, there is plenty of deep, warm ocean water that could fuel development in this area.
So, there is potential for future Imelda to grow into a hurricane, possibly a stronger hurricane, if it can develop a solid core of thunderstorms without getting sheared by upper-level winds.
 Ocean Heat Content
Early Look At Possible ImpactsEven if Imelda 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, due not only to Imelda but also to Humberto churning up the ocean.
Imelda could also draw close enough to produce strong wind gusts along parts of the Southeast coast, even if it never makes a landfall, as Hurricane Erin did in August.
Also, we expect some areas of locally heavy rain in parts of the Southeast — including the Carolinas and Virginia — Friday through the weekend, not associated with future Imelda.
Despite some ongoing drought, this rain-soaked ground could enhance the flash flood threat if Imelda makes landfall or is close enough to spread bands of heavier rain into those areas.
All interests in the Bahamas, the U.S. East Coast from Florida to North Carolina and Bermuda should closely monitor the progress of this forecast.
A Weird PossibilityOne factor in this forecast is that both Humberto and Imelda 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.
If this interaction happens in this case, it could help keep Imelda from making landfall and, if Humberto is strong and large enough, could even cause the storm to absorb Imelda.
We'll keep an eye on this possibility and spell out what it could mean for you if this "dance" becomes more imminent. |
