Friday, August 28, 2015

Tropical Storm Erika Soaks Puerto Rico, Hispaniola; Struggling to Survive as It Continues West

August 28,2015

Highlights

  • The center of Tropical Storm Erika is near Haiti, still very poorly organized.
  • Tropical storm warnings continue in the Dominican Republic, Haiti, the Turks and Caicos, and the central and southeast Bahamas.
  • Deadly, destructive flooding has been reported in Dominica, in the Lesser Antilles, Thursday. Strong wind gusts were reported in St. Croix and St. Thomas, westward to the Dominican Republic.
  • Erika has brought locally heavy rain and gusty winds to drought-suffering Puerto Rico and Hispaniola.
  • There is potential for Erika to dissipate as a tropical cyclone over the mountains eastern Cuba.
  • Erika's future track and intensity late this weekend and beyond remains highly uncertain regarding potential U.S. impact, which could occur somewhere along eastern Gulf Coast and/or Florida.
(MORE: Follow Tropical Storm Erika With Our New Interactive Storm Tracker)

Current Status

Erika Watches/Warnings

Current Wind Shear Analysis

Puerto Rico/Virgin Islands Radar

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Erika Struggles, But Still Soaks the Caribbean

Tropical Storm Erika is really struggling to remain marginally organized as it battles a hostile environment in the Caribbean Sea. Erika continues to face an uphill climb to maintain its identity as a tropical cyclone over the next day or so.
(MORE: Heart of the Hurricane Season is Here)
Satellite imagery continues to show Erika's convection (thunderstorms) displaced east of the center of circulation. At the same time, the center of circulate is ill-defined and has continued to trend south of previous National Hurricane Center forecasts. This is a common characteristic for a struggling tropical system, as Danny did the same thing earlier this month.
Land interaction with the higher terrain of Haiti and the Dominican Republic has effectively ripped apart Erika's circulation. Pico Duarte on the Dominican Republic is over 10,000 feet and Haiti has several peaks over 7,000 feet.
Strong westerly to southwesterly wind shear in the area has been consistently very strong, compared to average, in the Caribbean Sea this hurricane season, so far. If anything, Erika will be moving into an environment of higher wind shear over the next day or so.
The result is that Erika has been hobbling through the Caribbean the past few days and it is uncertain how much longer the storm will remain classified as a tropical cyclone. The official National Hurricane Center forecast now weakens Erika to a tropical depression later Saturday.
But that doesn't mean there may not be serious impacts. Regardless of Erika's tropical status and organization, locally heavy rain and flash flooding will continue to be threats through at least the end of this weekend.
A band of torrential rain resulted in deadly flash flooding on the island of Dominica in the Lesser Antilles, Thursday. Roads were washed out, homes were damaged and an airport flooded.
(MORE: Flooding Hits Dominica)
Canefield Airport near the capital of Roseau, Dominica, picked up 12.64 inches (322.4 millimeters) of rain in a 12-hour period ending just before 2 p.m. EDT Thursday.
Bands of locally heavy rain currently over Haiti will shift to to parts of Cuba and the possibly the Bahamas by Saturday.
Despite the long-term Caribbean drought, rain rates of several inches per hour could trigger flash flooding and mud/rockslides. Historically, some of the highest death tolls with Caribbean tropical cyclones have occurred in these situations.
The National Weather Service in San Juan, Puerto Rico, said some parts of the island had already picked up 3 to 4.5 inches of rainfall in Erika's rainbands as of early Friday morning.
(INTERACTIVE: Caribbean Radar)
Tropical storm force winds were reported across portions the U.S. Virgin Islands on Thursday, with that shifting west on Friday. Barahona in the Dominican Republic was gusting up to 52 mph as of late Friday evening. The highest measured gust so far in the Caribbean was 62 mph at St. Croix Thursday evening. St. Thomas registered a gust to 48 mph. The peak gust in San Juan, Puerto Rico, on Friday was only 33 mph. Some gusts to 50 mph were measured over the higher terrain of Puerto Rico Friday, according to NWS-San Juan.
Erika may continue to produce tropical storm force winds, mainly in gusts, primarily on the east and north sides of its circulation.

Erika's Possible Steering Pattern Ahead

Projected Path

Rainfall Outlook

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

An Uncertain Future: U.S. Threat?

As it stands, the forecast continues to contain a large amount of uncertainty with Erika. The system may not survive the hostile environment in the vicinity of Cuba on Saturday.
One complicating factor with the intensity forecast continues to be land interaction. Based on the tendency for Erika to continue on more of a westerly track, a substantial period of time with land interaction over Cuba appears likely. This may ultimately be the end of Erika, if it cannot survive past Saturday.
For now, potential impacts in the Bahamas from Erika are focusing on the southern and western most islands, with eastern Cuba taking more of a direct hit. No new warnings have been issued west of the Bahamas as of 11 p.m. Friday, mainly due to the challenging intensity forecast.
(FORECAST: Nassau | Turks & Caicos)
The potential U.S. impact remains somewhat uncertain. Here are the two most possible scenarios:
  • Florida still in the cone: Assuming Erika continues on a west to west-northwest track and survives the hostile environment on Saturday, it could pass near the Florida Keys on Sunday. In this scenario, Erika would have very little time to re-strengthen over the warm water north of Cuba, and would primarily be a heavy rain threat over the Florida peninsula, perhaps for several days. In this scenario, even if the center of what's left of Erika (as it may or may not stay a named storm) remains west of Florida entirely, the eastern side of the system would still likely impact the Sunshine State.
(FORECAST: MiamiDaytona Beach)
  • Westward wobbles: If Erika remains disorganized, it may tend to stay on a westward heading, instead of turning north of Cuba. In this scenario, Erika may dissipate entirely to a tropical wave sometime Saturday. The steering currents would tend to still bring the remnants of Erika into the Gulf of Mexico by Sunday into Monday. While a track over the Gulf may typically imply strengthening, upper-level shearing winds would be fairly hostile in this scenario. As a result, it is entirely possible that the system would never regain tropical status and would probably have only minimal impacts on the eastern Gulf Coast.
Regardless of the scenario, locally heavy rainfall could still be possible across western Florida and perhaps northwestward into the Florida panhandle.
All interests in The Bahamas, Cuba, Florida and the rest of the eastern Gulf Coast should continue to monitor the progress of Erika. The past few days have proven that even a weak tropical system can still cause significant destruction, particularly in terms of flash flooding.
(MORE: Expert Analysis | Hurricane Central)
Check back with The Weather Channel and weather.com for the latest updates on Erika.
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