Henri (2009)

A tropical wave that left the west coast of Africa on October 1 organized into a broad low on October 4 and became a tropical depression at 0000 UTC on October 6 about 675 nautical miles east of the Lesser Antilles. The system strengthened to Tropical Storm Henri six hours later and moved generally west‑northwestward. Henri reached its peak intensity early on October 7, then encountered stronger upper‑level winds that stripped convection away from the center. It weakened to a depression by 0600 UTC October 8 and became a remnant low about 1200 UTC October 8, moving west‑southwestward and dissipating by October 11 after its circulation was disrupted by the high terrain of Hispaniola.

Henri did not make any landfalls as a tropical cyclone. The circulation degenerated to a remnant low well north‑northeast of Anguilla on October 8 and later dissipated over the eastern Caribbean; there were no reported tropical‑cyclone‑force impacts on land associated with Henri.

The storm’s maximum sustained winds were 45 knots (about 52 mph) at its peak, with a minimum central pressure estimated at 1005 mb. At peak intensity Henri was a moderate tropical storm and never reached hurricane strength.

Observed storm surge and heavy rainfall reports tied directly to Henri are not recorded in the official data; there were no ship or land reports of tropical‑storm‑force winds, no documented storm surge heights, and no significant rainfall totals attributed to Henri in the NHC report. Satellite and scatterometer data were used to construct the best track rather than ground observations.

There were no reported deaths or damage associated with Henri. The storm produced little impact on land because it remained over the open tropical Atlantic and weakened rapidly under strong wind shear.

Notable aspects include that the storm’s formation was not well forecast—genesis was only mentioned about 36 hours before formation and model guidance generally failed to show development—and that NHC intensity forecasts performed very well, correctly anticipating a faster-than-modeled dissipation.