Danielle (2010)

A tropical depression formed about 450 nautical miles west-southwest of the Cape Verde Islands around 1800 UTC on 21 August 2010. It became a tropical storm the next day and moved generally westward across the central Atlantic. After a period of moderate shear, Danielle rapidly strengthened into a hurricane on 23 August and continued west-northwestward and northwestward before recurving northward and then northeastward well east of Bermuda. Danielle weakened as it turned into cooler waters and lost tropical characteristics, becoming post-tropical on 30 August and fully extratropical on 31 August; the remnant low dissipated a few days later on 3 September east-southeast of southern Greenland.

Danielle did not make any landfall as a tropical cyclone. A Tropical Storm Watch was issued for Bermuda on 27 August but was withdrawn on 28 August when the hurricane recurved to the east of the island chain. The storm remained over open ocean throughout its lifespan.

The highest estimated sustained winds were 115 kt (about 132 mph) at 1800 UTC on 27 August, and the minimum central pressure at peak intensity was 942 mb. At that time Danielle was a high-end Category 3 to Category 4 strength on the Saffir–Simpson scale (the report lists peak intensity as 115 kt, Category 4 strength over the central North Atlantic).

Storm surge impacts on land were not reported in the NHC report because Danielle stayed offshore. The most significant coastal effects were long-period swells and strong rip currents along parts of the U.S. East Coast and Florida. Notable marine reports included ship WCZ552 recording a near-center pressure of 974.1 mb and a peak wind of 64 kt about 20 nautical miles east-southeast of the center on 30 August. Rainfall totals on land are not highlighted in the report, as the cyclone remained far from major landmasses.

One death was associated with Danielle: a 47-year-old man drowned in rough surf at Seagull Park in Satellite Beach, Florida. Lifeguards rescued 68 people in Brevard County and several dozen in Volusia County from hazardous surf and rip currents. No other direct storm-related damage or fatalities were reported; the primary impacts were marine and coastal dangers from swells and rip currents.

Noteworthy items include relatively good foreknowledge of Danielle’s genesis (the precursor disturbance was mentioned in forecasts up to 48 hours before formation) but above-average track forecast errors at some lead times due to difficulty locating the system early and in predicting the timing and sharpness of its recurvature. Intensity estimates relied on reconnaissance aircraft measurements (flight-level winds to 119 kt and SFMR winds to 101 kt) and satellite analyses to determine the 115 kt peak.