23 August 2019

Watching two disturbances for potential development

The wave I mentioned in Wednesday's update near the Bahamas has indeed gotten better organized, and the odds of it becoming at least a tropical depression are higher.  As of Friday morning, it's centered just 40 miles southeast of Miami.  While it won't have time to have a big impact on Florida (aside from rain), places further up the coast into the Carolinas should be paying attention.

So far, the bulk of the rain and thunderstorms associated with it have remained offshore, and some models indicate that may continue, which would leave the Florida peninsula much drier than one might expect with a tropical system so close.  Otherwise, parts of the peninsula could see periods of very heavy rain today and Saturday.

Looking ahead 2-3 days, The European global model ensemble has many members indicating this will become Tropical Storm Dorian off the southeast U.S. coast, but without making a direct impact.  The American GFS global model ensemble generally keeps it weaker, moves it more over Florida, and has very few members indicating a tropical storm will form.  A fair balance would suggest that the Florida peninsula and eastern North Carolina will have higher-than-average chances of heavy rain in the coming days, but no hurricane alarm bells should be ringing.

South Floridians: Remember other visitors this time of year? Issac (8/26/12), Fay (8/19/08), Ernesto (8/30/06), Katrina (8/25/05), Jerry (8/23/95), Andrew (8/24/92), Cleo (8/27/64), Florida (8/26/49).  At least this visitor is quite innocent.

Shifting our attention to a fairly healthy wave in the deep tropics, about 1300 miles east of the Lesser Antilles, we remember that this is the time of year when Africa "wakes up" and we need to start paying close attention to the waves that exit the coast.  This wave left the African coast back on Monday and has been a feature of interest since then.

It's at a very low latitude (below 10°N) and is surrounded by dry air, so it's far from a sure thing that it will develop.  Regardless of development, the wave will move toward the west-northwest, bringing it to the Leeward Islands around Tuesday-Wednesday.  *IF* it does shrug off the dry air in the next couple of days, it will definitely be a feature to pay close attention to.  

By the way, if you're curious, Chantal is still lingering in the far northern Atlantic as a tropical depression.