Hurricane Chris Preliminary Report

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

Synoptic History

Chris originated as a tropical wave that moved across the African coast and into the eastern tropical Atlantic on 11 August. Moving westward, the wave acquired significant convection and signs of rotation on the 15th and became a depression on the 16th, midway between Africa and the Lesser Antilles.

The depression strengthened to a tropical storm by the 17th and to a hurricane on the 18th, while moving toward the northwest at 10 to 15 knots. This strengthening occurred even though there was evidence of vertical shearing from an upper-level low located to the northwest. Chris remained a hurricane for almost two days before the strong vertical wind shear significantly disrupted the circular symmetry of the cloud pattern and caused weakening.

The weakening storm turned northward on the 20th and northeastward on the 21st, moving on a trajectory around the western periphery of a persistent subtropical high pressure ridge anchored over the central north Atlantic Ocean. The center passed about 75 n mi east of Bermuda late on the 21st, but maximum winds were only 35 knots at this time and these winds were on the east side of the center. Sustained winds at Bermuda remained below 15 knots.

Accelerating northeastward, Chris strengthened again to 45 knots while staying ahead of a cold front. By the 24th, the storm merged with an extratropical baroclinic zone southeast of Newfoundland and shortly lost its identity.

Meteorological Statistics

The maximum flight level wind measured by reconnaissance aircraft was 61 knots at 700 millibars midday on the 20th. This was the first aircraft into Chris and, based on satellite intensity estimates, weakening had already begun. The central sea-level pressure by then was up to 1009 millibars. Dvorak estimates give a minimum pressure of 979 millibars and a maximum one-minute surface wind speed of 70 knots on the 19th.

There were several ship reports which were useful in determining Chris' wind speed: 

ship name       date/time     lat     lon      wind    pressure
unknown          17/1200      11.5    42.1    200/45   
unknown          17/1500      11.2    42.5    210/58    1001.0
unknown          17/1800      11.5    42.8    210/52    1010.0
Star Eagle       22/1800      37.5    60.5    210/34    1014.0
Adabelle Lykes   22/2100      37.1    58.2    190/40    1017.0

Casualty and Damage Statistics

There were no casualties or damage from Chris. However, Bermuda received 2.83 inches of rainfall from the passage of Chris.