Oyster Radio: Tropics Update: Friday morning summary on T.D. 7, Ernesto, and Atlantic waves

Summary:

At 5am EDT Friday, Tropical Depression 7 was located about 930 miles east of the Windward Islands, which is approximately 2,300 miles east-southeast of Miami.
Maximum sustained winds remain at 35mph. Although dry air will be near the system for the next few days, conditions appear favorable for some gradual intensification, and it could become Tropical Storm Gordon within the next 24-36 hours. The National Hurricane Center forecast currently has T.D. 7 becoming a tropical storm later today.
T.D. 7 is moving toward the west at 20mph. A quick westerly track should continue through the next 3 days as it is steered around high pressure in the central Atlantic, taking T.D. 7 into the eastern Caribbean Sea on Sunday.
Computer models beyond the 72 hour timeframe disagree on the track, largely due to difference in strength of the system, with a range of possibilities between Mexico to east of the Bahamas.
The official forecast keeps T.D. 7 a weak tropical storm as it moves through the Caribbean, but conditions could become increasingly hostile as it reaches the Windward Islands and some computer models dissipate the system into a tropical wave.

Ernesto has weakened to a tropical depression and should dissipate today as it continues to cross the mountainous terrain of southern Mexico.

Elsewhere, the remnants of Florence, located a few hundred miles north of Puerto Rico, is producing minimal shower activity. Re-development is not expected and the National Hurricane Center has given this system a low (0%) chance of becoming a cyclone again as it moves northwest at 10-15 mph.
A new tropical wave and low pressure system, classified as invest area 93L, has emerged off the coast of Africa. Conditions appear conducive for gradual organization, and there is a 50% chance of it becoming a tropical cyclone within the next 2 days.
93L is moving west-northwest around 20mph and initial computer models have this system becoming a tropical storm within 12-48 hours and moving west-northwest into the central Atlantic before curving northward. The next name on the 2012 storm list is Helene (pronounced “heh-LEEN”).

Florida outlook:

There are no tropical watches or warnings in effect for the United States and no part of Florida is within any error cone or at risk for tropical storm force winds.
Lingering ocean swells from Ernesto will affect the northern Gulf Coast, with wave heights of 2 to 3 feet producing a moderate rip current risk for all Florida Panhandle beaches.
It is too early to tell if T.D. 7 will have any impact to Florida. Computer guidance can be unreliable until a stronger system forms, but there is more confidence in the model tracks that take it south through the Caribbean.
A disturbed weather pattern across the Southeast U.S. will continue to bring high rain chances and the threat for heavy rainfall to much of North Florida through Saturday. A tropical wave over Cuba will also increase rain chances for southern Florida for the next few days.
¼ to ¾ inch of rain is currently forecast for most areas each day, but locally higher rainfall amounts could reach 2-3”, which will exacerbate flooding concerns. Frequent and dangerous lightning is also a high threat. A River Flood Warning is in effect for the St. Marks and Cypress Creek, with a Flood Watch in effect for the Choctawhatchee River.

More information on Tropical Depression Ernesto, Tropical Depression Seven and 93L can be found at www.nhc.noaa.gov.

Briefing slides are attached. Another update will be issued Friday evening.

Oyster Radio