MEC&F Expert Engineers : THANK YOU LORD FOR THE RAIN: Tropical Storm Erika Batters Caribbean; Florida, Bahamas on Alert

Friday, August 28, 2015

THANK YOU LORD FOR THE RAIN: Tropical Storm Erika Batters Caribbean; Florida, Bahamas on Alert


Erika will bring torrential rain, flash flooding, mudslides and gusty winds to many of the northern islands of the Caribbean prior to taking a turn toward the Bahamas and Florida this weekend.
Erika remains a tropical storm spinning about 155 miles east-southeast of Santo Domingo in the Dominican Republic, as of 5 a.m. EDT Friday.
Major Flooding From Tropical Storm Erika Sweeps Roseau, Dominica
Erika's Short-Term Impacts

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The greatest threat to lives and property will be from flash flooding and mudslides across Puerto Rico and the Dominican Republic.
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A general rainfall of 2-4 inches (50-100 mm) is forecast with locally higher amounts. In Puerto Rico and the northeastern part of the Dominican Republic, rainfall of 4-8 inches (150-200 mm) is likely with greater amounts falling on the mountains.
Flash flooding has occurred on some of the Leeward Islands. On the island of Dominica, flooding has led to catastrophic conditions. At least four people are dead in Dominica due to mudslides, the Associated Press reported.
At Canefield, Dominica, 8 inches of rain fell in six hours and received 12.70 inches of rain in 24 hours from Erika. Canefield received 2 inches of rain from Danny, just a few days earlier.
People Swept Away From Erika's Flooding in Dominica
Winds will average between 40 and 60 mph (64 to 95 kph), with higher gusts. Seas will be dangerous for bathers and boaters. Winds of this strength can down trees, cause sporadic power outages and damage roofs and poorly built structures.

As of late Thursday night, Governor Kenneth Mapp declared a State of Emergency and a imposed a curfew for St. Thomas in the U.S. Virgin Islands.
According to the Virgin Islands Emergency Management Agency, this decision was based on the damage inflicted to the trees, electrical lines and poles across the islands due to Erika.
The curfew will remain in place until 5:00 p.m., Friday Aug. 28, or until it is deemed safe to lift it.
Erika Path and Intensity Concerns This Weekend, Next Week
All interests from the Bahamas to Florida and the southeastern United States in general will need to monitor the track and strength of Erika into next week.
Satellite imagery of Erika (Image/NOAA)
At minimum, surf and seas will increase from southeast to northwest across the Bahamas, the north side of Cuba and the southern and eastern coast of Florida this weekend.
"There will be a Perigean spring tide related to a supermoon this weekend, so where there are onshore winds associated with Erika tides will be significantly higher than normal," AccuWeather Hurricane Expert Dan Kottlowski said.
These effects will be greatest along the Atlantic coast of Florida, including the back bays. East to northeast winds may cause some water to pile up.
There are multiple scenarios on the exact track and intensity of Erika once it clears the northern islands of the Caribbean. The possible tracks or window of movement ranges from the system slipping just to the west of Florida to right over Florida to curving to the east.

"Erika will have to survive strong wind shear and the frictional effects of the mountainous islands of Puerto Rico and Hispaniola," Kottlowski said.
Shear is the rapid change in the speed and direction of the wind from the surface of the Earth to the middle layers of the atmosphere.
Should Erika weaken negotiating Puerto Rico and Hispaniola, it could totally fall apart or perhaps struggle to reorganize.
"Waters are warm enough and wind shear is weaker in the stretch from Florida to the Bahamas," Kottlowski said. "So, if it were to survive the gauntlet of Puerto Rico and Hispaniola, it could gather strength."
Should Erika strengthen rapidly, the system could curve along or east of the Atlantic coast of Florida.
How soon Erika makes more of a turn to the northwest and then to the north will determine the extent of impacts in the Bahamas and Florida. If the system survives as far north as Florida, there will be concerns farther north into the Southern states, especially in the Carolinas and perhaps as far west as Louisiana.
There is also the chance the system stalls along the southeastern U.S. coast after negotiating Florida waters.
Which scenario unfolds will depend on the strength of an area of high pressure set to build over the western Atlantic Ocean late this week and into the weekend. This high is the reason for the cooler air pouring into the Northeast late this week.
At this point, the amount of rain, wind and flooding from Erika in Florida and the Bahamas will depend on the exact track and strength of the system this weekend and into early next week.
The last hurricane to hit Florida was Wilma in October 2005.
"This is a good time for residents of the Bahamas and Florida to review hurricane plans," Kottlowski said. "If Erika does indeed target Florida, there will be a big rush to complete preparations this weekend. However, it takes time to do some things such as moving boats from marinas to safety."
Shelves are empty at a Walmart in Coral Springs, Florida, as people prepare for potential Erika impacts. (Twitter Photo/@FallonKlivian)
"Be aware and do things now to mitigate flying debris," Kottlowski continued. "Even if Erika does not threaten, it is better to act on the side of caution now than wait."
The AccuWeather Hurricane Center will continue to provide information on Erika, as well as all other tropical features across all ocean basins.
AccuWeather Meteorologists Kristina Pydynowski, Jordan Root, Brett Rathbun and Alex Sosnowski contributed content to this story.