MEC&F Expert Engineers : Coast Guard advises mariners, public to be cautious of incoming tropical wave 99L

Wednesday, August 24, 2016

Coast Guard advises mariners, public to be cautious of incoming tropical wave 99L



August 24th, 2016 

SAN JUAN, Puerto Rico — The U.S. Coast Guard advises mariners, recreational boaters, swimmers, surfers and the general public in Puerto Rico and the U.S. Virgin Islands Wednesday to remain vigilant, exercise good judgment and make any preparations in anticipation to an incoming tropical wave.

“We advise citizens and boaters to make preparations and monitor official weather updates as this tropical wave moves through the area,” said Capt. Robert Warren, Coast Guard Sector San Juan commander and Captain of the Port San Juan. “Swimmers, recreational boaters and the general public should exercise caution and stay away from shoreline rocks until weather and surf conditions normalize. We will continue to monitor the winds and sea conditions in our area of responsibility.”

The Coast Guard requests that the public not call Coast Guard facilities for weather information, but that they listen to weather broadcasts and track internet updates through: http://www.nhc.noaa.gov/ and http://ift.tt/1pH3DKW

Here are a few tips to help mariners protect themselves, their families and their vessels:

• Do not go out to sea in a recreational boat if you know bad weather is approaching.

• Contact local marinas to ask for advice about securing your vessel. Marina operators are knowledgeable and can advise you on the best methods for securing your boat.

• Take action now. The effects of a tropical wave can be felt well in advance of its arrival and can prevent the safe completion of preparations.


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Recon crew finds 99L not organized enough to be TD or TS yet
By Mark Sudduth | August 24, 2016 - 12:56 PM | 99L, Atlantic Basin
 

Visible satellite image showing a fairly disorganized tropical wave moving through the NE Caribbean Sea

The value of the Hurricane Hunters is priceless. Their work and dedication is without equal in the weather world. Today, they proved it again with the flight in to invest area 99L. The data indicates that while the overall structure of the tropical wave has improved some, it’s not quite enough to name it a depression or a tropical storm.

Instead, we have a broad area of lower air pressure and plenty of general turning in the cloud motion. However, there is some fairly strong wind blowing over the top of the system and this is injecting dry mid-level air while also pushing any deep thunderstorms away from the weak low level center.

We can see this in the satellite image I have included here. Notice that the clouds are not symmetric in appearance but rather pushed off to the south and southeast. While there is clearly a weak circulation nearing Puerto Rico, it has yet to completely close off and become well defined. It may take another day before that happens which is generally what the models that develop this system indicate.

So for now, we still have a tropical wave but it is bringing with it strong winds and periods of heavy rain for portions of the islands of the NE Caribbean Sea. This will continue to spread WNW towards the Turks and Caicos and eventually the southeast Bahamas.

For what it’s worth, the latest GFS model run indicates once again that 99L will remain a weak system and never really impacts Florida. I do not understand why this is the solution the model is coming up with but it cannot be dismissed completely. We just don’t know – despite the insistence of the very reliable ECMWF or Euro model that this will become a hurricane and enter the Gulf of Mexico. Once I get a look at the latest output from this morning’s ECMWF run, I will post an update here, followed by a thorough discussion in my afternoon video blog. If you have our app, Hurricane Impact, be sure to check the video section later today for that update.

M. Sudduth 1pm ET Aug 24