After its center passed within 65 miles (105 km) of Bermuda around 00:00 UTC on September 19, the system encountered stronger wind shear and drier air.

However, peak surface winds of around 110 mph (180 km/h), with higher gusts, caused widespread damage to trees, roofs, crops, and power lines, most notably on the western end of the island chain.

As many as 600 buildings suffered roof damage, while 27,900 customers were left without power; though most of the network was quickly repaired, some electric outages persisted for at least 10 days.

On September 4, the wave encountered a mid- to upper-level trough of low pressure several hundred miles east of the Lesser Antilles.

As the trough became negatively tilted, or oriented northwest-to-southeast, strengthening anticyclonic flow on its east side promoted periods of enhanced convection close to the tropical wave.

These convective bursts, largely driven by diurnal cycles, led to the development of a broad surface low on the morning of September 12 as the disturbance turned north-northwest through the Turks and Caicos Islands.

[2] Observations from ships and nearby islands early on September 13 indicated that the low-level center had become better defined, and satellite imagery depicted the formation of a narrow curved spiral band in the disturbance's northeastern quadrant.

Based on this evidence, the NHC estimated that a tropical depression formed around 18:00 UTC on September 13, approximately 85 miles (137 km) east of Eleuthera in the Bahamas.

[4] By 00:00 UTC on September 16, Humberto intensified into the season's third hurricane as it temporarily stalled about 175 miles (282 km) east-northeast of Cape Canaveral, Florida.

[1] The hurricane developed a large eye, 35–40 miles (56–64 km) in diameter, surrounded by very cold cloud tops, a hallmark of intense thunderstorm activity.

By 00:00 UTC on September 20, the system had become devoid of organized deep convection, marking its transition to an extratropical cyclone while located 575 miles (925 km) south-southwest of Cape Race, Newfoundland.

The post-tropical cyclone continued to produce a large area of gale-force winds until it merged with an even larger extratropical low around 18:00 UTC on September 20.

[8] At 03:00 UTC on September 13, a tropical storm watch was issued for the east coast of the Florida Peninsula between Jupiter Inlet and the Volusia–Brevard County line.

[13] "The Causeway", a route connecting the airport to the territory's population centers, was closed as a precautionary measure shortly after a public curfew took effect at 21:00 UTC on September 18.

Grand Bahama International Airport in the northwestern part of the country reported ten-minute sustained winds of just 29 mph (47 km/h) as the storm passed to the east, and rainfall totals were light.

[9] Though unconfirmed, localized tornadic activity in Humberto's right-front quadrant may have been responsible for instances of isolated damage hours before hurricane-force winds spread across the islands.

[28] The lowest air pressure recorded in Bermuda was 970.4 mbar (28.66 inHg), and the highest waves in the seas off the territory's northern coast were analyzed near 42 ft (13 m).

[9] Analysis of observations from a buoy located 9 mi (14 km) off the northwestern coast indicated that parts of Bermuda experienced sustained winds near Category 3 intensity.

Elevated stations registered even more powerful winds; at 290 ft (88 m) above sea level, the Maritime Operations Centre on St. George's Island measured gusts to 144 mph (232 km/h).

[1][9] These intense winds caused extensive damage, particularly to trees, roofs, and power lines; the worst effects were concentrated in western areas.

A man attempting to ride out the storm on his yacht was briefly imperiled when the vessel broke free from its moorings and eventually wrecked on an island in the Great Sound.

[10] In the wake of the hurricane, fallen or low-hanging trees and power lines left some Bermuda roads impassable, so officials advised residents to remain indoors.

[9] Government offices, businesses, and most ferry routes resumed normal operations on September 20, while public schools remained closed for an additional day while building evaluations were underway.

[40] As a consequence of an ongoing slate tile shortage caused by the inability of local quarries to meet demand, permanent roof repairs were delayed for many residents.

[9][41] Premier of the British Virgin Islands Andrew Fahie expressed that his government was prepared to help Bermuda cope with the effects of hurricanes Humberto and Jerry.