Imelda Strengthens Over the Bahamas as U.S. Threat Lessens
Bermuda now in the path of Imelda, which could bring hurricane conditions later this week
Tropical Storm Imelda formed Sunday afternoon just east of the southern tip of Andros Island in the northwestern Bahamas and continues to strengthen near Great Abaco Island in the northern Bahamas – about 200 miles east of southeast Florida – on Monday.
Winds were gusting to tropical storm strength in the northwestern Bahamas Monday, where tropical storm warnings remain in effect. Though wind reports in the Bahamas have been largely lackluster, with most gusts so far mostly below 50 mph, Treasure Cay north of Great Abaco Island did gust to 83 mph Monday morning.
Hurricane Hunter airplanes investigating Imelda early Monday also found pressures continuing to fall at its center – indicating strengthening – into the upper 980s (millibars). These are low pressures for a mid-grade tropical storm, but winds take time to catch up to falling pressures so expect the winds to start ramping up today. Thankfully for the northern Bahamas, Imelda will be pulling away as it strengthens.
Dogleg right
In golfer’s parlance, Imelda’s cone now resembles a dogleg right, a sizeable shift from forecasts only a few days ago.
NHC’s 5-day forecast point from 5 AM Friday is about 625 miles west of the same forecast hour valid in its forecast from Monday morning. NHC’s average 5-day forecast error (over the past 5 years) is about 200 miles, so if Monday’s forecast verifies, that’s about triple the average error. Imelda has been a forecast challenge, to say the least.
As we discussed from the beginning, Imelda’s forecast was complicated by a possible interaction with Hurricane Humberto to the east. Although a true Fujiwhara dance – where the two systems rotate around each other – won’t happen, they’re close enough that Humberto’s large circulation will drag Imelda quickly eastward with it by tomorrow and Wednesday.
The positive weekend forecast trend south and east continued into early Monday. Tropical Storm Watches were discontinued Sunday afternoon for east-central Florida as tropical storm conditions should stay well east of Florida today and Tuesday as Imelda passes by to the east.
Unfortunately for Bermuda, the shift puts the archipelago in the crosshairs of a what could be a significant hurricane threat late Wednesday or early Thursday. As Imelda gets a boost from the jet stream and begins to transition into a powerful extratropical storm while it nears Bermuda, it could develop an especially dangerous and rare sting jet – a narrow band of violent and destructive winds along the back side of the cyclone that quickly descends to the surface.
These sting jets a very difficult to predict, but it’s worth noting for Bermuda, as sting jet winds can be particularly destructive when they hit.
Rains ahead of Imelda for the Carolinas
Meanwhile back here stateside, the plume of tropical air ahead of Imelda has already spread into the Carolinas, bringing widespread showers along a stalled cold front. Though the tropical tap will continue into Tuesday, the threat of widespread flooding continues to lessen for the southeast U.S. as Imelda makes its sharp turn much farther south and east than earlier forecast.
The main concern for the U.S. will be the threat of dangerous surf and marine conditions from both Imelda and Humberto this week, from Florida to the mid-Atlantic.
Humberto holding strong
Humberto continues to impress, with Hurricane Hunters finding a solid Category 4 hurricane Monday morning despite increasingly hostile wind shear and an eyewall replacement cycle taking a toll on its robust core.
With environmental conditions becoming less conducive ahead, Humberto is expected to gradually weaken as it hooks northeast well west of Bermuda tomorrow. Despite its center expected to stay about 200 miles west of Bermuda on Tuesday, with tropical storm winds extending about that far from its center, gusty winds could still reach Bermuda, and a Tropical Storm Watch is in effect there.
As we mentioned in Sunday’s newsletter, Humberto is only the third hurricane of the 2025 hurricane season, but the second Category 5 hurricane and third Category 4 or 5 hurricane this year. This is the highest percentage of Category 4 or 5 hurricanes to total hurricanes to-date in the satellite record.
This season also has recorded the fewest hurricanes to-date since 2013, though each hurricane has hit major (Category 3 or stronger) status. We’ll see if Imelda can (hopefully) buck the trend.
Good for us that Humberto is pulling Imelda away from the US but I hope neither storm causes serious harm to Bermuda.
Already too many major hurricanes this year though they have pretty much stayed out to sea. hope there aren't any more strong ones this year. Would like to think there wouldn't be any more at all this year but October seems to be a big month for them.
every day we thank you for your cogent explanations, helping us understand what is happening. you and all your colleagues are heroes, trying to keep us all safe. THANK YOU.