the 2005 atlantic hurricane season is the most active on record

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WORLD METEOROLOGICAL ORGANIZATION
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RA IV HURRICANE COMMITTEE
RA IV/HC-XXXI/Doc. 4.2(1)
(09.II.2009)
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THIRTY-FIRST SESSION
ITEM 4.2
NASSAU, BAHAMAS
20 TO 24 APRIL 2009
Original: ENGLISH
REVIEW OF THE PAST HURRICANE SEASON
REPORTS OF HURRICANES, TROPICAL STORMS, TROPICAL
DISTURBANCES AND RELATED FLOODING DURING 2008
(Submitted by British Caribbean Territories1)
INTRODUCTION
The 2008 Hurricane season was extremely active in the Caribbean Basin and caused significant
infrastructural damage and loss of life to a few countries. Six (6) tropical cyclones caused warnings
to be issued for the British Caribbean Territories (BCT) during 2008. Four of the cyclones, Gustav,
Hanna, Ike and Paloma, caused significant impacts due to wind, rainfall and storm surge. However,
two of the systems - Fay and Omar - did not cause any significant damage
FAY (August 16 – 18)
The Cayman Islands were placed under a tropical storm watch on the morning of 16 August
although Tropical Storm Fay was forecast to pass approximately 100 miles (160 km) to the
northwest of the islands. However, due to the cone of uncertainty there was the possibility that the
cyclone could pass with 20 miles (32 km) of Little Cayman and Cayman Brac (Sister Islands). The
watch was upgraded to a warning later that night for the Little Cayman and Cayman Brac, but Grand
Cayman was kept under a watch. All warning and watches were discontinued on the morning of
18 August because the centre of Fay was approximately 260 miles (420 km) north of the Sister
Islands and moving further away. Cayman Islands experienced little or no damage from Fay.
GUSTAV (August 26 – 30)
The Cayman Islands were placed under a hurricane watch on 26 August while Gustav was a
category 1 hurricane with its centre still over Haiti. The centre of Gustav was forecast to pass just to
the north of the Sister Islands. Gustav curved southward after its centre moved from Haiti and then
westward on 28 August and made landfall on eastern Jamaica. Gustav weakened to a tropical storm
while over Jamaica on 29 August but regained strength to a category 1 hurricane once it returned to
the open waters. The Sister Islands (Little Cayman and Cayman Brac) began to experience tropical
strength winds from midday and hurricane force winds began later that night, decreasing to tropical
storms winds at 0600UTC on 30 August.
1
The British Caribbean Territories (BCT) - a Member Territory of the WMO - comprise Anguilla, the British
Virgin Islands, the Cayman Islands, Montserrat, the Turks and Caicos Islands
RA IV/HC-XXXI/Doc. 4.2(1), p. 2
Gustav passed through the Cayman Islands as a category 1 hurricane and at its closest approach to
any of the three islands, the centre was 12 miles (19 km) to west of Little Cayman. The highest winds
speeds measured during Gustav’s passage were 63 mph (100 kph) in Cayman Brac and 59 mph
(95 kph) in Grand Cayman. There was 9.77 inches (248 mm) of rainfall as measured at the Gerrard
Smith International Airport in Cayman Brac, which led to low-lying flooding. The winds from Gustav
caused minor damage to buildings and brought down some utility poles. In Little Cayman, there were
waves with heights of 15 to 20 feet (4.6 to 6.1 metres) and a 2 to 4 feet (½ - 1 metre) storm surge.
HANNA (August 31 – September 3)
Tropical Storm Hanna, which was moving westward on 30 August, turned towards the south on 31
August. On 1 September, Hanna strengthened to a category 1 hurricane as its centre passed
within 15 miles (24 km) of Providenciales in the Turks and Caicos Islands. An amateur radio
operator measured winds of 40 to 50 mph (64-80 kph) with a gust of 78 mph (125 kph) and 8 inches
(203 mm) of rainfall in Providenciales. Hanna continued predominantly southward and weakened
over Great Inagua (Bahamas) to a tropical storm on 2 September. It reached its southernmost point
on 3 September, within approximately 7 miles of the ÎIe de la Torture off the north coast of Haiti, and
then moved eastward and finally northward in a counter-clockwise loop. Hanna made landfall on
North Caicos during the night of 3 September as a tropical storm.
On the island of Providenciales, there was widespread damage to property. Also twenty boats and
two aircrafts were severely damaged by the winds. Middle Caicos measured 13 inches (330 mm) of
rainfall over the three days. The newly-built causeway which linked Middle and North Caicos was
ravished by the heavy waves. There was also widespread flooding on the other islands.
RA IV/HC-XXXI/Doc. 4.2(1), p. 3
IKE (September 5 – 7)
Three days after Hanna left the Turks and Caicos Islands, Hurricane Ike appeared, developing into
one of the season’s major hurricanes. Ike crossed directly over the TCI on 5-6 September as a
category 4 hurricane with estimated winds of 135 mph (217 kph) with its centre passing within
25 miles (40 km) of Grand Turk during the night of 5 September. The highest measured wind speed
was 92 mph (148 kph), but this was on Providenciales, which was more than 60 miles (97 km) from
Ike’s centre. Ike produced primarily wind damage in the Turks and Caicos Islands, with 95% of the
buildings being damaged and over 700 persons lost their homes.
After Ike’s passage to the south of the Turks and Caicos Islands, it impacted on the northeast coast
of Cuba on 7 September and exited Cuba’s south-eastern coast on 8 September. Ike passed within
112 miles (180 km) of Little Cayman and Cayman Brac. In Cayman Brac the highest wind speed
measured was 38 mph (61 kph).
Hurricane Ike and the Turks and Caicos Islands (Inset)
Damage sustained from Hurricane Ike in the Turks & Caicos Islands
RA IV/HC-XXXI/Doc. 4.2(1), p. 4
Damage sustained from Hurricane Ike in the Turks & Caicos Islands
OMAR (October 15 – 16)
Omar had it genesis from a tropical wave in the central Caribbean Sea. Its initial movement was
towards the southeast but it turned towards the northeast and passed between the British Virgin
Islands and Anguilla on the night of 15 October (16th UTC) as a category 3 hurricane. There were
reports of damage due to the swells generated by Omar on the sheltered coastlines in some islands
of the Eastern Caribbean. However, since Omar was accelerating as it moved through the Virgin
Islands and Northern Leeward islands, the swells generated by Omar did minor coastal damage in
these islands. Two heavy barges also ran aground in Montserrat due to the swells, but the primary
impact was from rainfall, which caused flooding and landslides in the British Virgin Islands, Anguilla
and Montserrat.
PALOMA (November 6 – 8)
An extensive area of cloudiness and showers centered over the southwest Caribbean associated with
a broad area of low pressure was nearly stationary for sometime, this cloudiness developed into
Tropical Storm Paloma. Paloma moved predominately northward which caused the Cayman Islands
to issue a hurricane watch on 6 November. The storm eventually became a hurricane later that
night. While still south of the Cayman Islands, Paloma started a small turn towards the east and
continued intensification. Grand Cayman started to measure tropical storm force winds just after
midday on 7 November, while the Sister Islands started to feel the effects of storm force winds two
hours later. The centre of Hurricane Paloma’s closest point of approach was 33 miles (53 km) south
of Grand Cayman, 12 miles (19 km) south of Little Cayman and 7 miles (11 km) south of Cayman
Brac. This occurred during the night of the 7 November for Grand Cayman and predawn hours from
Little Cayman and Cayman Brac.
RA IV/HC-XXXI/Doc. 4.2(1), p. 5
Hurricane Paloma and the Cayman Islands
The highest measured wind speed in Grand Cayman was 42 mph (68 kph), with a gust of 59 mph
(95 kph), while in Cayman Brac the highest wind speed measured was 151 mph (243 kph). The
anemometer which measured this wind speed in Cayman Brac was 240 feet (73 metres) above mean
sea level. Minimal damage was experienced over the eastern districts of Grand Cayman as well as in
Little Cayman. Cayman Brac experienced extensive damage, especially to wooden structures with
numerous utility poles destroyed. Wave heights of 15 to 25 feet (4.6 to 7.6 metres) with a 4 to 8 foot
(1.2 to 2.4 metres) storm surge were noted over the Sister Islands. Rainfall totals of 17.77 inches
(451 mm) were measured in Cayman Brac for 8 November which resulted in widespread flooding.
In Grand Cayman 6.05 inches (154 mm) of rainfall was measured at the Owen Roberts International
Airport for the 24 hours period ending at 1200UTC on 8 November. This resulted in localized flooding
of low lying areas.
Polama’s wind damage and flooding in the Cayman Islands
RA IV/HC-XXXI/Doc. 4.2(1), p. 6
CONCLUSION
Despite the countries of the Cayman Islands and the Turks Caicos Islands being impacted by two
hurricanes during 2008, there was no loss of life. In fact the Cayman Islands which have been
impacted by two (2) major hurricanes during the past four (4) years had not experienced any loss of
life from these systems. This has been attributed this to the pre-hurricane season planning which
encompasses all stakeholders.
From an operational point of view, the major lessons from Omar were the forecasting and warning of
the swell and wave action on the western, usually sheltered coasts in the Lesser Antilles. From
recent experiences with Hurricane Lenny in 1999, which moved in a generally easterly direction in the
Caribbean Sea, and from other tropical storms and hurricanes that moved in a similar northerly track
to Omar, the primary cause of damage comes from the swells and waves. Therefore, even when
winds and rainfall may not be expected to produce significant damage, the sea is likely to produce
significant damage to the ports and other facilities facing the Caribbean Sea.
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