RA IV/HC-38/Doc. 3.2 (2), p. 9
WORLD METEOROLOGICAL ORGANIZATION______
RA IV HURRICANE COMMITTEE
THIRTY-EIGHTH SESSION
SAN JUAN, PUERTO RICO, USA
23 TO 26 APRIL 2016 / RA IV/HC-38/Doc. 3.2(2)
(14.III.2016)
______
ITEM 3.2
Original: SPANISH
REVIEW OF THE PAST HURRICANE SEASON
Reports of hurricanes, tropical storms, tropical disturbances and
related flooding during 2015
Report from the Dominican Republic
(Submitted by the Dominican Republic)
1 Introduction
The only impact during the 2015 cyclone season in the Dominican Republic was from Tropical Storm Erika, which hit the south-west of the country on the afternoon of Friday, 28 August.
The maximum rainfall reported was in the south-western community of Polo-Barahona, which experienced 222.5 mm of accumulated rain in 24 hours. According to the Meteorological Service’s national network of weather stations, other localities in the southern part of the Cordillera Central and the south-west of the Dominican Republic also received significant amounts of accumulated rainfall.
Erika was a weak storm, with maximum sustained winds of 41 kph at La Romana International Airport in the east of the country, while the maximum gust was 83 kph, recorded at María Montes de Barahona International Airport, the area where the storm struck. Advisory bulletins issued by the National Hurricane Centre in Miami reported winds of tropical storm intensity north-east of the centre, over Atlantic open waters and outside the territory of the Dominican Republic.
2 Use of alerts and warnings and associated effects of Erika
Fig. 1.- Track of Tropical Storm Erika across the Leeward Islands, adjacent waters south of Puerto Rico and south-west of the Dominican Republic
2.1 Alerts and warnings.- At 4 p.m. on Wednesday, 26 August 2015 (26 20:00 UTC), the Dominican Republic National Meteorological Office, in coordination with the Miami Regional Specialized Meteorological Centre in Miami, issued its first tropical storm alert bulletin for the eastern and northern coastal region between Cabo Engaño and Cabo Francés Viejo.
Fig. 2.- First alert issued by the Dominican Republic Meteorological Service
At 10 a.m. on Thursday, 27 August 2015 (27 14:00 UTC), the National Meteorological Office extended the above alert to the rest of the north coast, from Cabo Engaño to Manzanillo Bay, on the Dominican/Haitian border. At the same time, vessels off the northern coast were warned to remain in port owing to the possibility of eight to 12-foot waves with higher breakers.
Fig. 3.- Extension of the alert to the entire northern coast
At 4 p.m. on 27 August, changes were made to the alerts and warnings: the alert of tropical storm conditions was changed to a warning from Saona Island to Cabo Engaño and from Cabo Engaño to Manzanillo Bay and the alert of tropical storm conditions was from Saona Island to Punta Palenque. The centre of Erika was situated about 300 km west of Guadalupe, Lesser Antilles.
Fig. 4.- The alerts and warnings are changed
At 4 a.m. on Friday, 28 August (28 08:00 UTC), owing to a change in the movement of Erika, when it was situated about 95 km south/south-west of Ponce, Puerto Rico and some 190 km south-east of Saona Island, Dominican Republic, the National Meteorological Office decided to issue a tropical storm warning for the whole of the country’s coastal perimeter, as well as parts of the interior. Tropical Storm Erika remained a weak storm, since its minimum central pressure was around 1007 millibars.
Fig. 5.- Warning of storm conditions for the whole country
During the daytime and through the evening of Friday, 28 August Erika moved near westward, parallel to the south coast of the country, and the warning remained unchanged. Erika touched the Barahona Peninsula at around 7.00 p.m. local time on Friday, 28 August (28 23:00 UTC) moving very rapidly westward at about 33 kph. The maximum sustained wind reported at LaRomana International Airport was 41 kph, with gusts of 83 kph in Barahona. At Las Américas Airport, Santo Domingo, gusts of 81 kph were reported, while at Joaquin Balaguer Airport to the north of the city there were gusts of 74 kph.
Erika continued to move westward, leaving the Dominican Republic before midnight on Friday, 28 August and continuing across the southern part of Haiti until dawn on Saturday, 29 August, when it moved away from the island. The National Meteorological Office ended the tropical storm warning, but owing to the heavy rainfall, particularly in the south-western and southern parts of the country, it maintained a flood alert for Azua, Barahona, Bahoruco, Independencia and San Juan de La Maguana.
Fig. 6.- Chart showing the ending of the warnings
2.2 Associated effects.- The onset of the area of cloud cover and rainfall activity associated with Erika reached the Dominican Republic in the early afternoon of 28 August, affecting the province Altagracia and cities such as La Romana, San Pedro de Macorís and Santo Domingo in the east of the country, as shown on the channel’s infrared satellite image.
Fig. 7.- Infrared image at 1.25 p.m. local time on 28 August 2015
Later, at 3.45 p.m. local time on the same day, the infrared channel image showed the gradual increase in cloud and rain around the central region of the country.
Fig. 8.- Image for 3.45 p.m. on 28 August 2015
At 6.45 p.m. local time on 28 August, strong convection covered most of the Dominican Republic, producing heavy rain in the central, southern and south-western regions of the country.
Fig. 9.- Image for 6.45 p.m. local time on 28 August 2015
The highest accumulated rainfall occurred in localities on the southern slopes of the Cordillera Central, in the South-west and in isolated areas of the border region. The conventional weather station at Polo-Barahona recorded an accumulated value of 222.5 mm in 24 hours. In the regions mentioned above, accumulated rainfall generally varied between 70 and 122 mms.
NATIONAL METEOROLOGICAL OFFICE
DEPARTMENT OF CLIMATOLOGY – DATA PROCESSING DIVISION
ACCUMULATED PRECIPITATION ON 20 AUGUST 2015
TROPICAL STORM ERIKA
PRECIPITATION (mm)
RESEARCH DEPARTMENT
Fig. 10.- Map showing accumulated rainfall resulting from Erika on 28 August 2015. The arrow shows the location of the Polo Station in the far South-west.
2.3 Damage report by the Dominican Republic Emergency Operations Centre
(a) Fallen trees, signs and electricity poles, especially in the eastern region and the city of Santo Domingo. One aqueduct was affected, and a culvert-type bridge in the province of Azua was damaged;
(b) 2,458 homes were affected, 11 homes destroyed, eight communities cut off and 10,545 people evacuated;
(c) Provinces most affected: Santo Domingo (South), San Pedro de Macorís (East), María Trinidad Sánchez (North-east), San Cristóbal (South), El Seibo (East), Bani (South), Azua (South), Valverde-Mao (North-east), San Juan de la Maguana (South-west), Barahona (South-west).
2.4 Images of effects
Fig. 11.- Abnormal swells in Malecón (capital city) region
Fig. 12.- Heavy rain and strong winds
Fig. 13.- Effects of winds
Fig. 14.- Fallen trees
Fig. 15.- Road clearing work
3 Conclusions
· Tropical Storm Erika was a weak cyclone, which caused minimal damage in the Dominican Republic. The rain proved beneficial, as the country had suffered a lack of rainfall for several years, resulting in the need for measures to be taken with regard to water usage.
· Numerical prediction models relating to the track contained many uncertainties, and the official model was most effective for the south of the country. Despite initial predictions of a track across the north of the Dominican Republic, the emergency services were able to make appropriate decisions.
· The uncertainties in the models led to some criticism of the means of communication. Therefore, as meteorological services, we should continue to inform the media and the general public about the performance of these tools.
______