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Tropical Storm Erika
Status: Closed
| Type of posting | Posting date(EST): | Summary | Downloads |
|---|---|---|---|
| Pre-Landfall 1 | 8/28/2015 8:30:00 AM |
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Pre-Landfall 1 | Summary
Posting Date: August 28, 2015, 8:30:00 AM
Deadly Tropical Storm Erika Drenches Leeward Islands, Puerto Rico
With drenching rain, Tropical Storm Erika caused flooding, landslides, building collapse, and at least four deaths as it passed over parts of the Leeward Islands Thursday and moved toward Puerto Rico. Wind has not been a major concern with Erika—the fifth named storm of the Atlantic hurricane season—but the storm’s soaking rains have wreaked damage on the islands and continue to be a threat, notably to Puerto Rico, as it proceeds toward Florida.
Substantial damage occurred in Dominica, where four people were reported killed, three of them in a mudslide in the southeastern part of the island. The Caribbean Disaster Emergency Management Agency has reported 25 to 30 people missing. Villages have been inundated with water, and the heavy precipitation has resulted in numerous landslides and mudflows, which have undermined buildings, damaged vehicles, and washed out roads and at least one bridge. At the flooded airport, aircraft were damaged and the runway was strewn with storm debris.
Current Conditions
The Virgin Islands and Puerto Rico will experience tropical storm conditions, with heavy rain, in the early part of Friday. Parts of the Dominican Republic and Haiti should experience tropical storm conditions later in the day, followed by the Turks and Caicos Islands tonight. Saturday Erika is forecast to approach the central and northwestern Bahamas during the day and evening.
Rainfall estimates from Erika range from four to eight inches in most regions, although some areas of the Virgin Islands, Puerto Rico, the Dominican Republic and Haiti, the Turks and Caicos Islands, and the southeastern and central Bahamas could see up to 12 inches. Flash floods and mudslides are possible in those areas.
At present, tropical storm force winds extend outward up to 150 miles (240 km) to the north and east of the center, although some weakening should occur today as Erika moves over Hispaniola.
Tropical Storm Erika on August 28, en route to Hispaniola. (Source: NASA)
Meteorological Summary and Forecast
Winds from Erika are still relatively weak and wind damage in the Caribbean is not a major concern. In addition, tropical storm force winds are only on the right side of the disorganized asymmetrical system. The bigger issue from Erika is heavy precipitation. In the Caribbean, flooding can be a key driver of loss, even from storm systems with relatively weak winds that do not make landfall.
Erika’s forecast track has shifted to the west, and the storm is no longer considered likely to hit Florida as a hurricane. The system is now expected to pass over Hispaniola, whose high mountains tend to weaken or destroy passing storms. There is a distinct chance that the storm will not survive its passage. If it does survive, it will still be in a strong wind shear environment, limiting its intensification potential.
Beyond Saturday, the forecast is highly uncertain. If Erika does survive the next few days, it is unclear which track the system will follow, as it is highly dependent of its intensity when exiting this hostile environment. A stronger Erika could follow a path more to the east, which could result in track along the east coast of Florida, and a possible move toward the Carolinas, while a weaker Erika could mean a possible direct impact to Florida. The forecast models have shown a large spread beyond 48 hours.
Exposure at Risk
Caribbean residential building stock is dependent on exposure location—urban or rural—within an island, and regional differences. Older urban structures across the Caribbean exhibit a wide variety of construction materials, but the majority of new residential buildings are made of masonry, reinforced concrete, or both. There are diverse roofing practices across the Caribbean, with the most common type for residential structures being timber with metal roof covering, applied with corrugated or standing seam.
Most commercial structures in the Caribbean are low- to mid-rise, comprising of one to six stories. Small apartments, hotels, offices, and other low-rise commercial properties are usually masonry, or reinforced or block concrete. As with residential buildings, there is regional variability.
The unique concrete “bunker” style construction used for both residential and non-residential structures in Puerto Rico should limit any wind damage there to poorly built buildings. Despite similar building types and stock across the Caribbean, there is a wide range in building code type, use, and enforcement.
