A broad area of low-pressure associated with a tropical wave
crossed Dakar, Africa on 30 August. The Dakar vertical-time
section during that period showed a well marked cyclonic wind
shift below 700 mb and a 55-knot easterly jet at 550 mb. Surface
observations indicated that a 1005 mb low associated with the wave
moved just south of the Cape Verde Islands on the 31st. Although
the system had a well defined low- to middle- level circulation,
satellite images indicated that the deep convection was minimal.
The low-pressure area continued moving westward and during 3
September, it crossed an array of NOAA drifting buoys.
Data from these buoys helped to determine that the system had become a
tropical depression at 1200 UTC 3 September.
The depression continued almost due westward around the
periphery of a strong high pressure ridge with no significant
change in strength. Satellite images suggest that for the next
couple of days, deep convection was rather intermittent and not
well organized. In fact, on 6 September, the first reconnaissance
flight into the system found a broad circulation and only a few
squalls. As the depression approached the Lesser Antilles, upper-
level winds became more favorable for strengthening and satellite
images showed an increase in deep, organized convection. It is
estimated that the depression reached tropical storm status at 0600 UTC 7
September. An early reconnaissance flight on that day
reported peak winds of 62 knots at flight level and a minimum
pressure of 1001 mb confirming the strengthening of the system.
Hortense moved over Guadeloupe, where the pressure dropped to
998 mb and produced sustained winds of 46 knots with gusts to 70
knots. It also produced torrential rains. The tropical cyclone moved
westward into the eastern Caribbean and encountered a fast
eastward moving upper-level short wave. This increased the
vertical wind shear which temporarily inhibited strengthening. In
fact, high resolution visible satellite images clearly showed that
the low-level center of the tropical cyclone became exposed during
the morning of the 8th. A new burst of deep convection developed
over the center later in the afternoon and a gradual
intensification began. By then, the short-wave had moved out of the
area and the shear had relaxed. Hortense became a hurricane at
0600 UTC 9 September.
After slowing down just to the south southeast of Puerto Rico,
Hortense took a jog toward the northwest and the center moved over
southwestern Puerto Rico. Fixes from the San Juan WSR-88D radar indicate that the
eyewall of Hortense reached the coast near Guanica about 0600 UTC on the 10th
and moved over the southwestern tip of the island for about 2 hours.
Hortense moved through the Mona Passage and weakened slightly
while the circulation was interacting with land. The center passed
very close to Punta Cana, on the eastern tip of Dominican Republic
where a calm was felt and the pressure dropped to 988 mb. The
hurricane continued on a northwesterly track and the center moved
just east of the Turks and Caicos Islands. Hurricane conditions
were observed in some of these islands. Thereafter, Hortense
briefly reached category four status with a peak intensity of 120
knots and 935 mb minimum pressure at 0000 UTC 13 September.
A developing trough along the eastern United States forced the
hurricane to turn northward with an increase in forward speed. A
weakened Hurricane Hortense rapidly crossed eastern Nova Scotia on 15 September and
became extratropical while moving just south of Newfoundland later on that day.
Hortense was a wet hurricane. It produced about 10 inches of
rain in Guadeloupe and dumped between 15 and 20 inches of rain over
Puerto Rico and the U.S. Virgin Islands with possibly higher
amounts in the mountains. The Dominican Republic
also experienced torrential rains with a maximum of 19.25 inches in the
town of San Rafael de Yuma.
There are unconfirmed reports of gusts to 95 knots in the
southwestern tip of Puerto Rico about 0800 UTC 10 September. These
strong winds may have been a local effect caused by the Venturi
effect (acceleration between walls). Residents of the southwestern
portion of Puerto Rico reported calm winds and that the "stars were
out" as the eye crossed the area. Peak winds of hurricane force
were reported over the Dominican Republic, and hurricane force
winds were registered in Grand Turk and Nova Scotia.
Hortense was upgraded to a category four hurricane of 120 knots based on a
report from a hurricane hunter plane of 123 knots at 700 mb in the northeast
quadrant at 2130 UTC followed
by 128 knots in the southeast quadrant at 2220 UTC. The plane also
reported a minimum pressure of 935 mb, a closed eyewall of 11 n mi
in diameter and an excellent stadium (outward slope of the
convective clouds in the eyewall) effect at 2323 UTC. In addition,
satellite objective T-numbers were of the order of 6.5 on the
Dvorak scale, corresponding to an intensity 127 knots and a
pressure of 935 mb. Visible satellite images revealed a spectacular
cloud pattern with a clearly distinct eye during that time.
Hortense devastated portions of Puerto Rico but most of the damage was not
done by winds or storm surge. Instead, torrential rains produced flash
floods and mud slides which killed at least 18
people. A preliminary report from FEMA indicates that nearly 11,463 homes
were severely damaged by Hortense and
agricultural losses were of the order of 127 million dollars. In addition,
there was significant inland flooding in the low-lying areas as well as
serious coastal flooding in Nagabo, Guayanilla and Ponce.
Three people were killed and 21 reported missing in the Dominican
Republic and there was significant damage primarily in the
northeastern portion of the country. A school and one church were
demolished by winds or falling trees, numerous houses were damaged
and several electrical poles went down. There was a 9-foot storm
surge along the northeast coast. Roads were blocked due to flooding
both from the storm surge and from torrential rains. In Samana, 80
percent of the agriculture was damaged.