The chances of a tropical or subtropical depression forming in the Gulf of Mexico this weekend are holding at 90 percent, according to the National Hurricane Center.
Forecasters have been tracking an area of low pressure that as of Thursday night was located over the eastern Yucatan Peninsula.
That low is expected to slowly move northward and into the Gulf over the weekend -- and it could develop into the year's first tropical or subtropical system while it's there.
The hurricane center said the low, Invest 90L, continued to look better defined on Thursday night, and that trend is expected to continue through early next week. However the hurricane center noted that its rain and storm activity remained disorganized because of strong upper-level winds.
An Air Force Reserve reconnaissance aircraft could take a closer look at the system on Friday afternoon.
Forecasters said a tropical or subtropical depression could form by Saturday when the system is over the southeastern Gulf.
It is expected to track northward and could impact the northern Gulf Coast starting this weekend.
Tropical depression or not, the system is expected to bring heavy rain to Alabama and other parts of the Gulf Coast, according to the National Weather Service, and that is the main concern.
The National Weather Service in Mobile said there will be an "extreme" flood risk over parts of south Alabama and northwest Florida as the system moves closer.
Forecasters said flooding rains could begin as early as Friday but will more likely start on Saturday into Saturday night.
The weather service said widespread flash flooding will be a possibility in Mobile and Baldwin counties as well as the northwest Florida Panhandle through Tuesday.
There will be a "significant" risk farther inland over south Alabama as well.
Coastal flooding will also be a concern starting on Saturday with the high tide.
The system will also ramp up the surf along the beaches, and there will be a high risk of rip currents starting on Friday and lasting through the weekend, according to the weather service.
Confidence in severe storms and tornadoes is on the low side, the weather service said, and depends on the strength and track of the low.
Wind impacts are still unknown as of Thursday, but forecasters said winds could pick up by late Saturday and be confined closer to the coast. "Right now we are thinking winds of 20 to 30 mph are possible for coastal areas," the weather service said.
A system has to have a closed center of circulation and winds of at least 39 mph to be considered a tropical storm and get a name. The first name on this year's list is Alberto.
The Atlantic hurricane season officially begins on June 1.
Invest 90L continued to appear more organized on Thursday afternoon, forecasters said. (NOAA image)