It’s been a soap opera for Hurricane Lee. After rapidly strengthening to a Category 5 Thursday night at an historic pace – a blistering 85 mph increase in maximum winds in 24 hours (tied for the third fastest-strengthening Atlantic hurricane) – Lee hit a wall over the weekend, rapidly weakening back down to a Category 2 by Saturday evening.
After undergoing a quick eyewall replacement cycle early Sunday, Lee found its second wind and by Sunday afternoon had regained major (Category 3) status.
Thus far, the powerful hurricane has managed to avoid any direct entanglements with land, but as it slows and bends northward this week – sparing Florida and the Bahamas – the focus will turn to Bermuda for late week and potential impacts to the far northeast U.S. and the Canadian Maritimes by late weekend.
Will Lee reclaim its Category 5 crown?
Category 5 hurricanes are a rare breed. Only about 4% of all hurricanes and 2% of all named storms ever see winds exceeding 156 mph, the Category 5 threshold. They’re the kind of hurricanes we might expect to see on average every 4 or 5 years. Only 7 hurricane seasons of the 172 for which records exist have ever observed more than one Category 5 hurricane.
Needless to say, it takes an ideal environment to cook up a Category 5 hurricane. Wind shear has been persistent since Friday, but the shear has since subsided and conditions today into tomorrow will support a restrengthening, although it’s unlikely Lee will once again reach Category 5 status.
Its window of opportunity today may additionally be thwarted by what appears to be another ongoing eyewall replacement cycle. Although this may broaden Lee’s expansive wind field, it would also temporarily halt strengthening.
By mid-week, it’ll be moving over a cold wake zone created by Hurricanes Franklin and Idalia over the past few weeks.
Though waters in the deep Atlantic remain at record levels, waters farther north are the rare cool exception thanks to upwelling from the recent spate of big Atlantic hurricanes.
Bermuda in the cone
Lee should make its closest approach to Bermuda sometime late Thursday or Friday. Right now, the center is forecast to pass some 150 miles or so west of Bermuda. This is, however, near the average NHC forecast error 4-5 days out, so residents and visitors to Bermuda should monitor forecast changes carefully in the days ahead.
Regardless, Lee’s growing wind field may be problematic for Bermuda even if the center passes well west later this week.
Is Lee a threat to the Northeast U.S.?
First things first – Lee’s wind field has already begun to expand and will continue to do so this week. This is a big issue for long-period swell reaching the U.S. shoreline, expected to produce battering waves and life-threatening rip currents along much of the U.S. East Coast all week. The coastal concerns from this swell will increase as the week progresses, especially from the mid-Atlantic northward. This week will be a good week to stay out of an angry Atlantic.
Beyond Friday, the forecast gets tricky. The dip in the jet stream that will pull Lee northward will exit stage right and allow high pressure steering to move back in from the east. This will not only keep Lee from accelerating out to sea, but could even allow for a subtle bend back toward the northeast U.S.
For now, models still largely favor the core of the storm remaining offshore most of New England, but residents in the far northeast U.S. will need to watch the trends, especially from Nantucket and the Cape of Massachusetts to coastal Maine.
Lee’s peak winds will be much lower by the time it reaches the waters off New England – likely below hurricane strength – but the broad area of strong winds may act like a nor’easter to the coast if it slides too close. It’s too soon to say much more with confidence. The timing of greatest impacts for the Canadian Maritimes and any impact to coastal New England will be late weekend into early next week.
Whether or not Lee poses a direct threat to the Northeast U.S., dangerous surf conditions will be an ongoing hazard this week.
Another wave we’ll need to watch
This week marks the traditional peak of the Atlantic hurricane season and September is the time of year when long-track, destructive Cabo Verde hurricanes most commonly occur. So we keep a wary eye to Africa, where the seedlings for these notorious hurricanes – known as tropical waves – take shape.
We’ll be following another potent tropical wave this week that’s currently rolling south of the Cabo Verde islands off Africa. Models indicate gradual development and since it won’t be immediately turning out to sea, we’ll need to monitor its progress. For now, the system is no threat to land.
Margot expected to become a hurricane but stay out to sea
Margot continues to spin over the open east Atlantic. Although it’s expected to strengthen into a hurricane this week, it will track northward and stay over open water.
