The system in the western Gulf of Mexico is slowly beginning to consolidate. A circulation is forming in the southwestern Gulf, which is expected to eventually organize into a tropical depression tonight or tomorrow as it pulls to the north.
The eventual system will be a combination of the disturbance we’ve been following near the southern Mexican coast and a weak disturbance with its accompanying moisture that has trekked across the ocean. They will meet later today, and the combination is expected to become a depression.
High pressure is pushing into the Gulf from the Atlantic, and the flow around the high will provide the oomph to move the combo system toward Louisiana or Mississippi. The bad weather will begin tomorrow in the form of heavy rain and gusty winds.
The upper-level winds are forecast to continue to be fairly hostile, so a strong storm is not expected in the northern Gulf. The upper winds will be blowing over the system from the southwest to the northeast, which will push the gustiest thunderstorms to the right-front side and ahead of the circulation. This is why the weather at the coast will deteriorate well before the center crosses the coastline.
The contrast in pressure between the potential depression or storm and the high-pressure system of the Atlantic will create gusty winds on the east (right) side of the system. There will not be much bad weather on the left side of the circulation as the system comes ashore – likely on Saturday.
There is some chance the winds could get strong enough to cross into tropical-storm range. If wind speeds of at least 40 mph are found anywhere related to the circulation, the system would be named Tropical Storm Claudette.
Because the strongest winds over the water will be blowing directly onshore, and the northern Gulf coast is so vulnerable to storm surge, some Gulf water rise is expected along the coast. Broadly, the biggest threat appears to be from heavy rain, however.
There has been unusually heavy rain across the Louisiana coastal sections already this spring, and a foot of rain could fall with this system in some locations.
As high pressure builds across Florida into the Gulf, it will bring drier air with it, which will include some Saharan dust. Rain chances in South Florida will dramatically diminish over the weekend, though the skies will likely be milky from the dust.
Elsewhere in the tropics, nothing is expected to develop into next week.