A tropical depression formed from a tropical wave about 525 nautical miles east of the northern Leeward Islands at 0000 UTC 19 September 2021. It became Tropical Storm Peter six hours later and moved generally west-northwestward north of the Leeward Islands and Puerto Rico. Peter was short-lived, lasting until it weakened to a depression by 1800 UTC 21 September and degenerated into a trough early on 23 September about 200 n mi north of Puerto Rico; its remnants later produced a separate non-tropical low east of Bermuda before dissipating near Newfoundland.
Peter did not make any landfalls. Its center passed roughly 100 nautical miles north of the northern Leeward Islands and remained north of Puerto Rico and the U.S. Virgin Islands throughout its life, so no coastal watches or warnings were issued.
Peter’s peak intensity was estimated at 45 knots (about 52 mph) with a minimum central pressure of 1005 mb. The storm maintained that peak (45 kt) from 1800 UTC 19 September through 0000 UTC 21 September before weakening under increasing southwesterly wind shear.
Although the center stayed offshore, Peter’s outer rain bands produced locally heavy rainfall in Puerto Rico. Gauge totals of 3.76 inches were measured at Lares and Morovis; other gauges reported 3.63 inches at Corozal and 3.38 inches at Bayamón. A combined gauge-and-radar analysis indicated isolated areas, especially in Lares municipality, may have received 5 to 6 inches. No storm surge reports of notable heights were reported in the NHC report.
There were no reports of damage or casualties—no deaths or injuries—directly attributed to Peter. Impacts were limited to localized heavy rain and minor flooding in parts of Puerto Rico. The storm was notable for forming later and farther west than some early forecasts expected, and NHC track forecasts had larger-than-average errors at longer lead times as Peter moved farther west than predicted due to the storm’s decoupling by strong shear. NHC intensity forecasts performed well, correctly anticipating the lack of significant strengthening.
Paid members can generate summaries tailored to the counties of their choice. The Peter 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 Peter → (opens at nhc.noaa.gov)| Time (UTC) | Status | Lat | Lon | Winds (kt) | Pressure (mb) | Record |
|---|---|---|---|---|---|---|
| 2021-09-19 00:00 | TD | 16.40 | -52.70 | 30 | 1007 | |
| 2021-09-19 06:00 | TS | 16.80 | -54.40 | 35 | 1006 | |
| 2021-09-19 12:00 | TS | 17.30 | -55.80 | 40 | 1006 | |
| 2021-09-19 18:00 | TS | 17.90 | -57.00 | 45 | 1005 | |
| 2021-09-20 00:00 | TS | 18.40 | -58.00 | 45 | 1005 | |
| 2021-09-20 06:00 | TS | 18.80 | -59.00 | 45 | 1005 | |
| 2021-09-20 12:00 | TS | 19.20 | -60.10 | 45 | 1006 | |
| 2021-09-20 18:00 | TS | 19.50 | -61.20 | 45 | 1007 | |
| 2021-09-21 00:00 | TS | 19.60 | -62.30 | 45 | 1007 | |
| 2021-09-21 06:00 | TS | 19.60 | -63.20 | 40 | 1007 | |
| 2021-09-21 12:00 | TS | 19.80 | -64.00 | 35 | 1008 | |
| 2021-09-21 18:00 | TD | 20.20 | -64.60 | 30 | 1008 | |
| 2021-09-22 00:00 | TD | 20.60 | -65.20 | 30 | 1008 | |
| 2021-09-22 06:00 | TD | 21.00 | -65.80 | 30 | 1008 | |
| 2021-09-22 12:00 | TD | 21.40 | -66.40 | 30 | 1008 | |
| 2021-09-22 18:00 | TD | 21.70 | -66.90 | 30 | 1008 |
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.