James Spann: Tropical depression expected to form in Gulf, bring heavy rain to Alabama

RADAR CHECK: We have a number of slow-moving showers and storms on radar this afternoon across the southern two-thirds of Alabama; heavier storms are generating lots of lightning and very heavy rain. These storms will slowly fade tonight.

FRIDAY/SATURDAY: Expect no real change in our weather. It will be warm and very humid, and we will deal with scattered showers and storms. They form in random places, and there is no way of knowing far in advance when and where they will pop up; you just have to keep an eye on radar trends. Most of the showers and storms will come during the afternoon and evening hours, but we can’t rule out a late-night or morning shower in this air mass. Away from the storms, we will have a mix of sun and clouds with highs in the 80s.

Beyond Saturday, the weather will all depend on a tropical system moving up from the Gulf of Mexico.

TROPICAL UPDATE: The National Hurricane Center now is showing a 90 percent chance of tropical depression/storm formation in the Gulf over the next five days. Models are coming into better agreement; most take it toward the Mississippi coast on Monday, with a slow journey northward through inland parts of Mississippi Tuesday and Wednesday.

The system will most likely be a minimal tropical storm (called Alberto) at the time of landfall; the main threats will involve rain and flooding, and not wind.

NORTH/CENTRAL ALABAMA: I’m not totally sure we will see much of a change in the weather Sunday; it will be warm and humid with scattered showers and storms. But rain coverage should increase Monday and into Tuesday and Wednesday of next week as the tropical system lifts northward. Rain could be heavy at times, and flooding is a real possibility for the first half of next week, with rain amounts of 3 to 5 inches.

THE GULF COAST: National Weather Service Mobile has already issued a flash flood watch for Mobile and Baldwin counties, and and for Escambia, Okaloosa and Santa Rosa counties in Florida. Also, a coastal flood watch is in effect along with a high surf advisory.

The weather Saturday on the coast won’t be too bad, with about two to four hours of sun, along with scattered showers and storms. However, rain will increase Sunday and Monday with only a limited amount of sun as the tropical system approaches. Here are the key points if you have a beach trip planned:

  • The disturbance in the Gulf is not expected to be a hurricane. There’s a fair chance it will be a lower-end tropical storm, meaning the main threat is from rain and flooding instead of wind.
  • NWS Mobile is now forecasting 6 to 12 inches of rain for the Alabama and northwest Florida coast Saturday through Tuesday, with potential for isolated amounts of more than 12 inches. This, needless to say, will bring a very significant risk of flooding.

  • There will be a high danger of rip tides along the coast through Memorial Day; red flags are already flying. Do not get into the waters of the Gulf; the risk is simply not worth it.
  • A few isolated, short-lived tornadoes will be possible along and east of where the tropical system moves onshore, mainly Monday.
  • Weather should begin to improve on the Gulf Coast Monday night and Tuesday as the system moves farther inland.
  • As is the case with every tropical system, keep alert for potential forecast changes in coming days.

REST OF NEXT WEEK: The tropical system should dissipate across the Gulf Coast states by the middle of next week, and showers and storms should become fewer in number by Friday. Highs through the week will be in the 80s.

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For more weather news and information from James Spann and his team, visit AlabamaWx.

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