As mentioned the past couple of days, how well the storm handled hostile conditions in the Atlantic in the last 24-36 hours would be critical in determining how 99L would impact our weather in south Florida. It didn’t handle the dry air and shear well and it remains disorganized Friday morning.
The disturbance continues to move northwest toward south Florida with arrival in our area later this weekend into Monday of next week. The chances of this tropical wave showing any type of significant development before it reaches south Florida are low given less than ideal conditions in the past day or so and only marginally favorable conditions through this weekend.
The system will move through the area as a typical tropical wave, with an increase in easterly breezes especially on Sunday, and higher rain chances from Sunday into the first part of next week. Nothing more than that.
As far as your weekend plans, proceed as you normally would. Saturday will see a typical mix of sun and clouds and scattered to numerous showers and storms with the greatest coverage during the afternoon. On Sunday, as the tropical wave approaches, easterly winds will increase a bit particularly over Collier Co. Speeds will be generally in the 10-20 mph range and expect a higher chance of showers and storms given the increase in moisture that these systems usually bring. High temperatures may be held down a few degrees due more clouds. Seas will increase well offshore especially over the Gulf.
Confidence is high that the weak storm system will make it into the eastern Gulf early next week. We will continue to be on the east side, which is the more moist side. A continuation of numerous showers and storms can be expected for at least the first couple of days of next week. These storms will be heavy rain producers and can easily drop an inch or two of rain in short order. Localized flooding issues may occur in areas that see persistent rain.
As far as what it will do once it gets into the Gulf still remains highly uncertain. Most of the computer model guidance keeps 99L weak with very little development through mid-week. With water temperatures fairly high in the Gulf and no chance for land interaction and lighter wind shear than its been experiencing, it may have a chance to intensify once its in the Gulf for a few days, which obviously would pose a potential threat to the northern Gulf Coast. It will likely be another evaluate and wait approach for them.
So to summarize, Saturday will see partly to mostly cloudy skies and scattered thunderstorms. On Sunday as the tropical wave approaches, clouds will increase and winds will pick up a bit particularly over southern sections of the region and over the open waters of the Gulf. Showers and storms will be more numerous all of which will produce very heavy rainfall that could lead to localized flooding issues. This will continue into Monday, Tuesday and possibly Wednesday until the system gets far enough away from us to have little influence. Impacts in our area are not expected to be significant.