Hurricane Danielle (1998)

Hurricane Danielle

Category 2 hurricane (SSHWS/NWS)
Danielle as a Category 2 hurricane on September 1
Formed	August 24, 1998
Dissipated	September 8, 1998 (extratropical after September 3)
Highest winds	1-minute sustained: 105 mph (165 km/h)
Lowest pressure	960 mbar (hPa); 28.35 inHg
Fatalities	None reported
Damage	$50,000 (1998 USD)
Areas affected	Eastern Seaboard, Northeastern United States, Canadian Maritimes, British Isles
Part of the 1998 Atlantic hurricane season

Hurricane Danielle resulted in minor damage throughout its duration as a tropical cyclone in late August and early September 1998. The fourth named storm and second hurricane of the annual hurricane season, Danielle originated from a tropical wave that emerged off the western coast of Africa on August 21. Tracking generally west-northwestward, the disturbance was initially disorganized; under favorable atmospheric conditions, shower and thunderstorm activity began to consolidate around a low-pressure center. Following a series of satellite intensity estimates, the system was upgraded to Tropical Depression Four during the pre-dawn hours of August 24, and further to Tropical Storm Danielle that afternoon. Moving around the southern periphery of the Azores High located in the northeastern Atlantic, quick intensification to hurricane status occurred early on August 25. By 0600 UTC the following day, Danielle reached an initial peak intensity of 105 mph (165 km/h), a Category 2 hurricane. Increased wind shear from a nearby trough encroached on further development later that day, and subsequently led to slight weakening. By 1200 UTC on August 27, despite continued unfavorable conditions, Danielle reached a second peak intensity equal to the first. Weakening once ensued late on August 27 in addition to the days following, and Danielle was a low-end Category 1 hurricane by August 31 as its forward speed slowed.

As the cyclone reached the western periphery of the ridge that steered it across the Atlantic for much of its existence, it began yet another period of intensification, and once again attained a peak intensity as a Category 2 hurricane. Passing northwest of Bermuda, Danielle weakened to Category 1 hurricane strength, but for a final time intensified into a 105 mph (165 km/h) tropical cyclone thereafter. As the cyclone passed over increasingly cool sea surface temperatures and became intertwined in a baroclinic zone, it began to undergo an extratropical transition. At 0000 UTC on September 4, Danielle was no longer considered a tropical cyclone, despite retaining hurricane-force winds. Several days later, the remnants of Danielle merged with a larger extratropical low and became indistinguishable. As a tropical cyclone, it produced heavy rainfall in Puerto Rico and the Lesser Antilles, leading to flooding. Tropical storm-force winds were observed in Bermuda even though the cyclone passed well northwest of the island. During Danielle's transition to an extratropical cyclone, it produced light rain and led to minor beach erosion in Newfoundland. The larger extratropical low that merged with the system resulted in large waves off the coast of the United Kingdom, leading to major beach erosion and coastal flooding. Overall, no fatalities were reported with the system and it caused an estimated $50,000 (1998 USD) in damage.