Hurricane Luis Preliminary Report

Excerpts courtesy of the
National Hurricane Center (NHC)
--Written by Miles B. Lawrence

Synoptic History

Luis was a category 4 Cape Verde hurricane that wreaked harm and havoc on the northeasternmost of the Leeward Islands, with an estimated sixteen dead and two-and -a-half billion dollars in damages.

Luis was first detected as a tropical wave and circulation of low clouds on 26 August over the far eastern tropical Atlantic between the coast of Africa and the Cape Verde Islands. The low-level cloud circulation moved westward and is estimated to have developed a weak surface circulation on the 27th near the Cape Verde Islands.

While Luis was developing, there were three other tropical cyclones in the Atlantic, to the west and northwest...Humberto, Iris and Karen. Luis strengthened from a depression to a storm on the 29th, but its deep convection fluctuated for the next two days while there was strong vertical shear nearby. The shear diminished on the 30th; an eye formed and Luis quickly became a hurricane. The intensification process continued for the next two days as Luis moved west-northwestward. A reconnaissance aircraft reached the hurricane late on the 3rd of September and confirmed the satellite intensity estimates of a category 4 hurricane on the Saffir/Simpson scale. Luis was located about 600 n mi east of the Lesser Antilles at this time.

The track heading turned from westward to northwestward on the 5th and the hurricane moved across the northeastern Leeward Islands. The center passed directly over Barbuda and close enough to the northeast of Antigua, St. Barthelemy, St. Martin and Anguilla that the southern portion of the eyewall affected these islands. Luis' sustained winds in the eyewall were as high as 115 knots at this time, just below 120-knot maximum values which had occurred for the previous 48 hours.

Luis was a large hurricane. The inner diameter of the eyewall was 40 n mi as it moved over the islands. In addition to the eyewall conditions described above, Nevis, St. Kitts, St. Eustatius and the northernmost British Virgin Islands experienced hurricane-force wind speeds, while tropical storm conditions affected the remainder of the British and U.S. Virgin Islands and the eastern islands of Puerto Rico.

Luis gradually recurved across the north Atlantic. The center of the hurricane passed about 200 miles west of Bermuda on the 9th of September, causing tropical storm force winds there. Luis became extratropical on the 11th, as it moved over eastern Newfoundland, where high winds and sea conditions were also reported.

Meteorological Statistics

The highest reconnaissance wind speed was 146 knots at 1306 UTC on the 4th at a flight level of 700 mb. A surface pressure of 945 mb was measured at this time. The surface pressure did not reach its minimum value of 935 mb until later on the 7th, at which time aircraft winds were near 120 knots. The ship TEAL ARROW was in the center of the hurricane at 1800 UTC on the 6th and measured a sea-level pressure of 942 mb. The ship reported sustained winds of 64 knots at 1500 UTC and measured 99 knots at 2100 UTC and again at 0300 UTC on the 7th. The highest ship gusts were 125 knots and wave heights to 50 feet were estimated.

The official highest sustained surface wind attained by Luis is estimated to be 120 knots from the 3rd through the 5th while it was approaching the Leeward Islands. This speed is 82 percent of the highest aircraft wind speed of 146 knots. Sustained wind speeds were still at 115 knots as Luis moved over the islands.

Sustained hurricane-force winds were also reported from Antigua, Guadeloupe, St. Barthelemy and Sr. Maartin. The observations of sustained near-surface wind speeds of 105 and 108 knots at Antigua and St. Barthelemy imply that even higher values may have occurred nearby. Since the eye of the hurricane went over Barbuda, it is expected that sustained winds of near 115 knots were experienced there. The winds at Anguilla were likely in the 105- to 115-knot range.

Later and further north, Bermuda reported a maximum sustained wind of 40 knots as the center passed some 200 n mi to the west.

The QUEEN ELIZABETH 2 encountered a rogue wave of 95 feet early on the 11th while located 200 n mi south of eastern Newfoundland and 120 n mi southeast of the center of the tropical cyclone, which is estimated to have had 80-knot sustained winds at that time. A nearby Canadian data buoy reported a peak wave height of 98 feet at about the same time.

On the afternoon of the 8th, ten drifting data buoys were deployed by the U.S. Air Force Reserve 53rd Weather Reconnaissance Squadron some 300 n mi ahead of Luis, along 31 degrees north latitude and from 71 to 66 degrees west longitude. Sustained winds of 72 knots with gusts to 95 knots were measured as the hurricane passed, but this observation was not at the location of strongest winds as indicated by aircraft reconnaissance data. The buoys also measured pressure and air and sea temperature and there was a 3.5 C decrease in sea surface temperature to the east of the center after Luis went by.

Casualty and Damage Statistics

The hurricane killed at least 16 people and caused extensive damage when it moved across the northeastern edge of the Leeward Islands of the Caribbean. Nine died in St. Martin, two in Antigua, two in Puerto Rico, one in Guadeloupe, and one in Dominica. Days later, there was one storm-related death in Newfoundland.

Dollar damage totals are unknown. At Barbuda, where a full Category 4 hurricane was experienced, the damage to structures was estimated at 70 percent along with severe flooding and erosion. The estimate for St. Maartin and St. Martin is 60 percent damage. The prime minister of Antigua was quoted as saying that nearly half the homes on that island were destroyed. A damage estimate for St Maartin, alone, is 1.8 billion dollars. With great uncertainty, the total damage estimate for Hurricane Luis is temporarily set at 2.5 billion U.S. dollars.