A low pressure area that formed along a front over the central United States moved off the East Coast and became nearly stationary between the Bahamas and Bermuda. The system developed a defined surface circulation and was classified as a subtropical storm on 8 November 2011 about 385 nautical miles southwest of Bermuda. It transitioned to a tropical storm later on 8 November, moved slowly west-northwestward then northward, and turned north-northeast ahead of an approaching trough before becoming post-tropical on 12 November and dissipating after merging with a cold front on 13 November.
There were no landfalls recorded for Sean. The storm passed about 75 nautical miles to the west-northwest of Bermuda at about 1200 UTC on 11 November, producing brief tropical-storm-force conditions there, but its center did not cross the island.
Sean’s maximum sustained winds reached 55 knots (about 63 mph) and its lowest central pressure was 982 mb at 1200 UTC on 10 November. That peak intensity corresponds to a moderate tropical storm; it did not reach hurricane strength.
Observed storm surge and rainfall impacts were minimal in the official record. Marine observations included sustained winds of 37 kt and a gust to 54 kt reported near Bermuda around 0900 UTC on 11 November, and buoy 41047 and several ships reported tropical-storm-force winds. The report does not list specific storm surge heights or substantial rainfall totals at cities or counties.
There were no reports of damage or casualties associated with Sean. The storm’s development from an extratropical low to subtropical and then to a tropical storm, and the relatively small size and brief period of peak winds, limited impacts to marine interests and nearby Bermuda.
Noteworthy items: Sean’s formation was first mentioned about 54 hours before genesis, but a high probability of subtropical or tropical formation was only indicated about 12 hours before it formed. Forecast track and intensity errors from the National Hurricane Center were generally lower than 5-year means and lower than most guidance model errors for this storm.
Paid members can generate summaries tailored to the counties of their choice. The Sean TCR covers impacts across many counties and states — a Pinellas County resident doesn't need the Asheville detail, and a Buncombe County resident doesn't need the Tampa surge data.
Upgrade for county-specific summariesSummary above produced from the National Hurricane Center's official post-storm Tropical Cyclone Report. Read the full report for casualty lists, damage estimates by area, forecast critique, and detailed meteorological discussion:
📄 Read NHC's full report on Sean → (opens at nhc.noaa.gov)| Time (UTC) | Status | Lat | Lon | Winds (kt) | Pressure (mb) | Record |
|---|---|---|---|---|---|---|
| 2011-11-06 00:00 | EX | 28.50 | -70.00 | 45 | 1005 | |
| 2011-11-06 06:00 | EX | 28.50 | -69.20 | 45 | 1005 | |
| 2011-11-06 12:00 | EX | 28.40 | -68.80 | 45 | 1005 | |
| 2011-11-06 18:00 | EX | 28.00 | -68.50 | 45 | 1005 | |
| 2011-11-07 00:00 | EX | 27.90 | -68.60 | 45 | 1005 | |
| 2011-11-07 06:00 | EX | 27.70 | -68.70 | 40 | 1005 | |
| 2011-11-07 12:00 | EX | 27.50 | -69.00 | 40 | 1005 | |
| 2011-11-07 18:00 | LO | 27.60 | -69.30 | 40 | 1004 | |
| 2011-11-08 00:00 | LO | 27.60 | -69.60 | 40 | 1002 | |
| 2011-11-08 06:00 | SS | 27.70 | -69.80 | 40 | 1001 | |
| 2011-11-08 12:00 | SS | 27.80 | -70.00 | 45 | 1000 | |
| 2011-11-08 18:00 | TS | 27.80 | -70.00 | 45 | 999 | |
| 2011-11-09 00:00 | TS | 27.80 | -70.10 | 45 | 999 | |
| 2011-11-09 06:00 | TS | 27.80 | -70.20 | 50 | 996 | |
| 2011-11-09 12:00 | TS | 27.90 | -70.40 | 55 | 994 | |
| 2011-11-09 18:00 | TS | 28.30 | -70.60 | 55 | 991 | |
| 2011-11-10 00:00 | TS | 29.00 | -70.70 | 55 | 987 | |
| 2011-11-10 06:00 | TS | 29.70 | -70.90 | 55 | 984 | |
| 2011-11-10 12:00 | TS | 30.20 | -70.70 | 55 | 982 | |
| 2011-11-10 18:00 | TS | 30.50 | -70.00 | 55 | 983 | |
| 2011-11-11 00:00 | TS | 31.00 | -69.00 | 55 | 984 | |
| 2011-11-11 06:00 | TS | 32.20 | -67.20 | 50 | 987 | |
| 2011-11-11 12:00 | TS | 33.40 | -65.30 | 45 | 991 | |
| 2011-11-11 18:00 | TS | 34.80 | -62.60 | 40 | 995 | |
| 2011-11-12 00:00 | EX | 35.90 | -59.40 | 35 | 1000 | |
| 2011-11-12 06:00 | EX | 38.00 | -57.20 | 35 | 1000 | |
| 2011-11-12 12:00 | EX | 40.00 | -55.00 | 35 | 1000 | |
| 2011-11-12 18:00 | EX | 42.50 | -52.40 | 35 | 1000 |
Source: NOAA National Hurricane Center HURDAT2 best-track database (nhc.noaa.gov/data). Data is in the public domain. Best-track positions and intensities are post-storm reanalysis estimates and may differ from real-time advisories.