Hurricane Dennis (1999)

Infobox Hurricane
Name=Hurricane Dennis
Type=hurricane
Year=1999
Basin=Atl
Image location=Hurricane Dennis (1999) GOES.jpg


Formed=August 24, 1999
Dissipated=September 7, 1999
1-min winds=90
Pressure=962
Da

Inflated=-1
Fatalities=4 direct
Areas=Bahamas, North Carolina, Virginia, Maryland, Pennsylvania
Hurricane season=1999 Atlantic hurricane season

Hurricane Dennis of the 1999 Atlantic hurricane season was a Category 2 hurricane that was erratic in both track and intensity. Although it never made landfall as a hurricane, the storm was responsible for producing hurricane force winds along the North Carolina coast along with beach erosion. The hurricane caused $157 million in damage, and killed four people. The heavy rains from Dennis also set the stage for destructive flooding from Hurricane Floyd about two weeks later.

Meteorological history

A tropical wave moved off the African coast on August 17. The wave continued west-northwestward, not organizing until the 21st when an increase in convection occurred. A low-level circulation slowly developed as it passed north of the Lesser Antilles, and on August 24 it was upgraded to Tropical Depression Five while located around 220 statute miles east of Grand Turk. It moved to the west-northwest, and later on the 24th it strengthened into Tropical Storm Dennis.

Located at the eastern end of an elongated trough, Dennis was affected by westerly shear. Despite the unfavorable conditions, the storm intensified, and reached hurricane status on August 26 over the Bahamas. Due to the trough, Dennis moved very erratically, varying between a fast forward speed to a near drift in its developmental stages. After passing through the Bahamas, the shear decreased, and Dennis was able to reach Category 2 strength on the 28th.

A mid-latitude trough brought Dennis north and northeastward, causing it to parallel the Florida through North Carolina coastlines. While east of Florida on August 28, Dennis peaked at 105 mph (170 km/h) winds, though the wind field never resembled a classical tightly wound hurricane. The eye wall was around convert|35|mi|km wide, and at some occasions Reconnaissance Aircraft did not even report an eye. This may be because some upper level shear remained. Dennis weakened as it continued northeastward, but still brought hurricane force winds to the North Carolina coast on August 30.

Hurricane Dennis became involved with a cold front, which caused vertical shear and cool, dry air to impact the circulation. A ridge of high pressure to its north caused Dennis to stall, leading to the cyclone's weakening to a tropical storm on September 1 as a result of the unfavorable conditions. On the 1st and 2nd, with disorganized convection and a large wind field, Dennis resembled a subtropical cyclone or even an extratropical storm, but it retained its warm core as it drifted southward over warmer waters. Dennis restrengthened as it turned to the west-northwest, andmade landfall near Harkers Island, North Carolina on September 5 while just below hurricane strength. The storm rapidly weakened over land, and turned northward through Virginia. It became extratropical on September 7, and was absorbed by a larger extratropical low on the 8th over Canada.

Impact

Dennis left $157 million (1999 USD) in damage and four deaths in North Carolina, Virginia and the northeastern United States. The heavy rain from Dennis staged a catastrophic flood disaster wrought by Hurricane Floyd about two weeks later.

Bahamas

Dennis brought tropical storm and hurricane force winds to the Bahamas. In Grand Bahama, a weather station reported winds of convert|40|mi/h|km/h|abbr=on while other areas reported winds between 70-75 mph. A 976 mbar reading and storm tides 1-3 feet above normal occurred as the center of the storm moved across Abaco Island on August 28. The only official rainfall total from the Bahamas was convert|4.4|in|mm at Eleuthera and Abaco. [http://www.nhc.noaa.gov/1999dennis.html Dennis 1999 report] ] Dennis caused moderate damage across the Bahamas. On Abaco Island, the rain caused heavy flooding and storm surge washed out roads. Dennis also caused considerable damage to trees and boats. [http://www.hurricanecity.com/dam/dam1999.htm Hurricane City.com] ] However, there were no reports of deaths or injuries and damage totals from the Bahamas are unavailable.

outheastern United States

When Dennis was offshore the storm brought winds up to convert|35|mi/h|km/h|abbr=on with gusts reaching to convert|40|mi/h|km/h|abbr=on to Jacksonville, Florida. In St. Augustine, a weather station reported a convert|35|mi/h|km/h|abbr=on gust. Rainfall from Dennis was minimal, amounting to only convert|0.11|in|mm at Jacksonville International Airport. Dennis also brought storm tides between 6-8 feet in some areas and there was only minor beach erosion. The strong rip currents brought by Dennis caused one fatality. [ [http://www.usatoday.com/weather/huricane/1999/atlantic/wdrptjax.htm CNN Report from Florida] ]

The state of Georgia reported convert|35|mi/h|km/h|abbr=on wind gusts and only a trace of rain. [http://www.usatoday.com/weather/huricane/1999/atlantic/wdrptchs.htm CNN report from Georgia and South Carolina] ]

In South Carolina, numerous weather stations reported winds between 40-55 mph and gusts reaching hurricane force. Rainfall up to convert|1.2|in|mm fell in some areas while buoys offshore reported tides convert|2|ft|m above normal. Minor to moderate beach erosion was reported from Charleston to Colleton County. Damage in South Carolina was limited to downed trees and scattered power outages. [http://www.usatoday.com/weather/huricane/1999/atlantic/wdrptchs.htm CNN report from Georgia and South Carolina] ]

North Carolina

On August 30, Dennis brought tropical storm force winds with gusts up to hurricane force to the North Carolina coast. In Oregon Inlet, there were convert|60|mi/h|km/h|abbr=on winds, while Cape Hatteras and Wrightsville Beach reported gusts between 90-100 mph. A weather station reported convert|90|mi/h|km/h|abbr=on wind gusts and a barometric pressure reading of 977 mbar. When Dennis made landfall on September 4, it brought tropical storm force winds to much of eastern North Carolina. convert|45|mi/h|km/h|abbr=on winds were reported in Cherry Point, North Carolina. Storm tides 3-5 feet above normal were reported along the North Carolina coast. Because Dennis was a slow moving storm, it produced heavy rains across eastern North Carolina. The highest rainfall total was convert|19.13|in|mm in Ocracoke, while rainfall between 3-10 inches was reported elsewhere. The rain was beneficial as it broke a prolonged dry spell, but it also staged the catastrophic flood disaster caused by Hurricane Floyd a month later. The heavy rains caused significant flooding that left $60 million dollars (1999 USD) in structural damage and $37 million dollars (1999 USD) in agricultural damage — totaling $97 million (1999 USD). In addition, Dennis caused two indirect deaths when two cars collided during the storm. The heavy rains knocked down power lines near Wilmington, North Carolina, leaving 56,000 residents without electricity.

Virginia

In Virginia, winds up to convert|50|mi/h|km/h|abbr=on with gusts up to convert|75|mi/h|km/h|abbr=on were reported at Langley Air Force Base, and tides were reported 2-4 feet above normal. 1-3 inches of rain fell across much of southeastern Virginia, and an F2 tornado spawned by Dennis touched down in Hampton, damaging several structures and injuring fifteen people, six of them seriously. Damage from the tornado was $7 million (1995 USD). The tropical storm force winds also knocked out power to 22,500 residents in southeastern Virginia. In all, Dennis left $97 million (1999 USD) in damage across southeastern Virginia.

Name "Dennis" used again in 2005

Despite the damage, the name Dennis was not retired and was re-used in 2005. However, the name Dennis was retired after the 2005 storm and replaced by Don for the 2011 season.

ee also

* List of tropical cyclones
* List of Atlantic hurricanes

ources

* [http://www.nhc.noaa.gov/1999dennis.html Hurricane Dennis of 1999]
* [http://www.cnn.com/WEATHER/9908/31/storms.02/Hurricane Dennis weakens (CNN.com)]
* [http://www.wunderground.com/hurricane/at199904.aspHurricane Dennis track]

Notes