Isaac (2006)

A tropical depression formed from a tropical wave in the central Atlantic on 27 September 2006 about 810 nautical miles east-southeast of Bermuda. The system became Tropical Storm Isaac on 28 September and slowly organized while moving generally west-northwest. Isaac strengthened to hurricane strength on 30 September and reached its peak on 1 October while located about 285 nautical miles east of Bermuda. After peak intensity the hurricane turned north-northeast, accelerated, weakened, and became extratropical on 3 October after passing southeast of Newfoundland.

Isaac did not make landfall. The center passed about 35 nautical miles southeast of the Avalon Peninsula of Newfoundland late on 2 October, and tropical-storm-force conditions affected parts of the southern Avalon Peninsula that day. Tropical storm watches and warnings were issued for the Avalon, Burin, and Bonavista peninsulas as Isaac approached, and the warnings were discontinued once conditions eased.

The storm’s maximum sustained winds peaked at 75 knots (approximately 85 mph) and the minimum central pressure was 985 mb, making Isaac a Category 1 hurricane at its strongest. Best-track data show sustained winds reached 75 kt around 0000–0600 UTC on 1 October before gradual weakening began.

Storm surge and rainfall were modest where Isaac affected land. Observations from Newfoundland included a reported storm surge of about 1.0 ft at Cape Race. Rainfall totals over the warned areas were generally one inch or less due to the cyclone’s rapid forward motion. Notable wind reports included sustained 40 kt with 52 kt gusts at Cape Race, a private station gust of 41 kt at Cape Pine, and buoy 44138 reporting sustained 45 kt with 56 kt gusts about 60 nmi east of the center.

There were no reported deaths or damage associated with Isaac. The most significant impacts were marine and coastal—strong winds reported by ships, buoys, and offshore oil platforms—but land impacts in Newfoundland were limited. Forecasts issued before genesis gave early notice of potential development; official track errors were below average at 12–48 hours but larger than average at longer ranges, mainly because Isaac unexpectedly accelerated north-northeast ahead of a deep trough.