Atlantic Hurricanes during 1998

During 1998, the Atlantic experienced an above average season. Ten tropical storms reached hurricane strength. The hurricane season runs from the beginning of June through the end of November with peak activity during August and September. The 1886 to 1994 Atlantic seasonal average is 8.4 tropical storms with 4.9 reaching hurricane strength.

Coasts and islands are extremely vulnerable to damage from tropical cyclones and hurricanes. These severe storms can have winds that extend inland for hundreds of miles. A combination of factors such as strong winds and storm surge determine the destructive power of a hurricane.

Tropical Cyclone - the general term for all cyclonic circulations originating over tropical waters

Tropical Depression - a tropical cyclone with wind speeds of up to 33 kt

Tropical Storm - a tropical cyclone with wind speed range of 34 - 63 kt

Hurricane - a tropical cyclone with wind speeds greater than 64 kt

In order to track hurricanes and issue warnings, the National Oceanic and Atmospheric Administration's (NOAA) National Hurricane Center (NHC) keeps a close eye on the storms. When a tropical cyclone reaches tropical storm strength, it receives a name. When a tropical cyclone reaches hurricane strength, NHC uses a disaster-potential scale to predict the hazard potential of a hurricane approaching landfall. The Saffir-Simpson scale (see last page for description) assigns hurricanes to one of five categories according to wind speed.

Defense Meteorological Satellite Program Data Archive at the National Geophysical Data Center

This slide set shows satellite views of the 10 Atlantic Basin tropical cyclones which reached hurricane strength in the 1998 season with imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). DMSP operates day/night and dawn/dusk satellites. Daytime images are taken with sunlight striking perpendicular to the storm while dawn/dusk images have sunlight glancing across the top of the storm. Images from the F12 and F14 satellites are daytime images; those from the F13 satellite are dawn/dusk.

Each hurricane is shown in two separate slides showing views in the OLS visible near-infrared band and the OLS thermal-infrared band. The spatial resolution of the imagery used is 2.7 km. Odd numbered slides show thermal infrared images (10.5-12.6 um). Even numbered slides show visible near-infrared images (0.4-1.1 um). The thermal infrared images show the temperatures of the cloud tops, and ocean and land surfaces, while the visible near-infrared images show reflected sunlight during the day and reflected moonlight or man-made lights during the night.

Abbreviations Used: Conversion Factors:

n mi = nautical mile 1 nautical mile = 1.15 miles

kt = knot or 1.85 kilometers

mb = millibar 1 knot = 1.15 miles per hour

um = micron or 1.85 kilometers per hour

Published by the National Geophysical Data Center

National Environmental Satellite, Data, and Information Service

National Oceanic and Atmospheric Administration

U.S. Department of Commerce

For information about the complete DMSP Archive at the

National Geophysical Data Center (NGDC) please contact:

NOAA/NGDC Code E/GC2 Email: ngdc.dmsp@noaa.gov

325 Broadway WWW: http://www.ngdc.noaa.gov

Boulder, CO 80303-3328 FAX: 303-497-6513

Slides 1 & 2 Hurricane Bonnie

Dates as a Named Storm: August 19-30, 1998

Maximum Wind Speed: 100 kt

Bonnie was the first hurricane of the season in the Atlantic Ocean. Bonnie gradually strengthened and reached hurricane status on August 22nd when it was located 200 n mi north of the eastern tip of Hispaniola. The storm headed west-northwest passing just east of Cape Fear, NC before making land fall near Wilmington, NC as a border line Category 2/3 hurricane. The storm then took a northeast to east track and became extratropical on August 30th. Three people died as a consequence of Bonnie and damage reports were estimated at $360 million.

Slides 3 & 4 Hurricane Danielle

Dates as a Tropical Storm: August 24-Sept. 3, 1998

Maximum Wind Speed: 90 kt

Danielle had a long track across the Atlantic Ocean. Although it did not seriously impact land as a tropical cyclone, it battered portions of Great Britain as an extratropical system. Based on satellite data, this rapidly strengthening hurricane reached a peak intensity of near 90 knots around 0600 UTC on August 26th, while centered about 900 n mi east of the Leeward Islands. Sustained winds of 34 knots with gusts to 47 knots were observed at Bermuda on September 2nd. No reports of damage or casualties were made as a result of this storm.

Slides 5 & 6 Hurricane Earl

Dates as a Named Storm: August 31-Sept. 3, 1998

Maximum Wind Speed: 87 kt

A tropical depression became Tropical Storm Earl centered about 500 n mi south-southwest of New Orleans, Louisiana at 1800 UTC on August 30th. Earl reached hurricane status at 1200 UTC on September 2nd, briefly reaching category 2. Earl made landfall as a category 1 hurricane, resulting in significant storm surge flooding in the "Big Bend" area near Panama City, Florida Hurricane Earl was directly responsible for three deaths and $79 million in property damage.

Slides 7 & 8 Hurricane Georges

Dates as a Named Storm: Sept. 15-October 1, 1998

Maximum Wind Speed: 130 kt

Georges originated from a tropical wave, which crossed the west coast of Africa late on September 13th. Georges continued to gradually strengthen over the next several days, reaching hurricane intensity around 1800 UTC on September 17th when an eye feature became evident. Georges was the second deadliest and second strongest hurricane within the Atlantic basin during the 1998 season. Its 17 day journey resulted in seven landfalls, extending from northeastern Caribbean to the coast of Mississippi, resulting in 602 fatalities and $3 billion in property damage.

Slides 9 & 10 Hurricane Ivan

Dates as a Named Storm: September 19-27, 1998

Maximum Wind Speed: 80 kt

A tropical depression became Hurricane Ivan which was the first in a trio of hurricanes to form and then remain over the eastern Atlantic Ocean during the latter part of September. Ivan's hurricane stage occurred rather far to the north at approximately 30N. Its peak wind intensity of about 80 kt was reached on the morning of the 26th, the hurricane was then about 300 n mi. west of the Azores Islands. There were no reports of damage or casualties.

Slides 11 & 12 Hurricane Jeanne

Dates as a Named Storm: Sept. 21-October 1, 1998

Maximum Wind Speed: 90 kt

Jeanne formed from a tropical wave that was slow to emerge from western Africa. Jeanne continued moving toward the west-northwest, strengthening to its estimated peak intensity of 90 knots while located about 580 n mi west of the westernmost Cape Verde Islands. It remained over the eastern Atlantic. It brushed the Cape Verde Islands early in its development, and also caused some gusty winds over the Azores just before losing tropical characteristics. There were no known casualties or damages caused by Jeanne.

Slides 13 & 14 Hurricane Karl

Dates as a Named Storm: September 23-28, 1998

Maximum Wind Speed: 90 kt

Hurricane Karl was one of four hurricanes in existence over the Atlantic basin at one time. According to records at the National Hurricane Center, the last time four hurricanes were in existence in the Atlantic at the same time was on August 22, 1893. It remained over water without any direct effects to land.

Slides 15 & 16 Hurricane Lisa

Dates as a Named Storm: October 5-9, 1998

Maximum Wind Speed: 65 kt

Lisa originated from a tropical wave which moved westward from Africa into the eastern tropical Atlantic Ocean on September 29th. Lisa briefly strengthened to a 65 knot hurricane on October 9th, before merging with an extratropical frontal system in the far North Atlantic. It stayed over the Atlantic Ocean and did not effect land. There were no reports of damage or casualties.

Slides 17 & 18 Hurricane Mitch

Dates as a Named Storm: October 22-Nov. 5, 1998

MaximumWind Speed: 168 kt

Mitch was responsible for over nine thousand deaths predominately from rain-induced flooding in portions of Central America, mainly in Honduras and Nicaragua. This makes Mitch one of the deadliest Atlantic tropical cyclones in history. The 905 mb minimum central pressure and estimated maximum sustained wind speed of 155 knots over the western Caribbean make Mitch the strongest October hurricane (records began in 1886). Mitch moved across the Yucatan Peninsula and southern Florida as a tropical

Slides 19 & 20 Hurricane Nicole

Dates as a Named Storm: Nov. 24-Dec. 1, 1998

Maximum Wind Speed: 75 kt

Late season Hurricane Nicole was a tenacious tropical cyclone that persisted for several days over the northeast Atlantic. Nicole was moving over a region of anomalously warm sea surface temperatures of the order of 2 or 3 degrees. This anomalous feature was probably partially responsible for the intensification of the system. There are no reports of casualty and damage from Nicole.

Saffir-Simpson Hurricane Scale

The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region.

Category One Hurricane:

Wind Speeds: 64 - 82 kt Storm Surge: 4 - 5 ft above normal

Types of Damage: Damage to unanchored mobile homes, shrubbery, and trees. No real damage to building structures. Some coastal road flooding and minor pier damage.

Category Two Hurricane:

Wind Speeds: 83 - 95 kt Storm Surge: 6 - 8 ft above normal

Types of Damage: Roof, door, and window damage to buildings. Considerable damage to vegetation, mobile homes, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center.

Category Three Hurricane:

Wind Speeds: 96 - 113 kt Storm Surge: 9 - 12 ft above normal

Types of Damage: Structural damage to small residences and utility buildings, some curtainwall failures. Mobile homes destroyed. Flooding destroys smaller structures near the coast, larger structures damaged by floating debris. Terrain lower than 5 feet above sea level may flood up to 6 miles inland.

Category Four Hurricane:

Wind Speeds: 114 - 135 kt Storm Surge: 13 - 18 ft above normal

Types of Damage: Extensive curtainwall failures, some complete roof structure failure on small residences. Major erosion of beach areas. Major damage to lower floors of structures near shore. Terrain continuously lower than 10 feet above sea level flooded requiring massive evacuation of residential areas as far as 6 miles inland.

Category Five Hurricane:

Wind Speeds: > 135 kt Storm Surge: > 18 ft above normal

Types of Damage: Complete roof failure on many residences and industrial buildings. Some complete building failures, small utility buildings blown over. Major damage to lower floors of all structures located less than 15 feet above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground up to 10 miles inland.

Storm statistics and storm track information were obtained from operational warnings posted by the Joint Typhoon Warning Center in Guam and compiled by Tom Metcalf at http://www.solar.ifa.hawaii.edu/Tropical/. Due to the operational status of the storm data compiled in this document, typhoon statistics and storm tracks may not agree with data from post-track analyses of the storms.