After an unusually dry finish to the spring, the start of summer has been tinged green -- on the weather maps -- as we've sat on the northern fringes of a developing tropical system in the southern Gulf of Mexico. That tropical system, while impressive-looking on satellite tonight, it still fairly disorganized, with most of the deep convection to the east of a difficult-to-pinpoint area of low pressure. This is because wind shear remains strong, for now, across the central and southern Gulf; this wind shear is prolonging, but not blocking, the path to Debby. By late Saturday, we will likely have our fourth named storm of the season.

Throughout the day, the center of low pressure (at one point, multiple centers) has danced around on the western periphery of the storm's cloud shield. While more difficult to detect at night, since we don't have visible satellite imagery available, it appears as shear relaxes the center is tucking itself closer to the deep thunderstorm activity, a sign that the system -- designated Invest 96L by the National Hurricane Center -- is about to become better organized. The system will drift to the north and northwest over the next 24 hours with drift being the opperative word; steering currents are collapsing and, once in the central Gulf, the system's motion will slow to a crawl if not stop altogether.

This is important for a couple of reasons. First, Invest 96L will likely stall over some of the deepest, warmest waters in the entire Gulf of Mexico. This is a recipe for strengthening as upper level wind relaxes. Secondly, that stall will mean a cold front moving into the southeast and, eventually, north Florida later this weekend will essentially be able to act like a straw and suck tropical moisture our way.

There are still many details to hash out, especially beyond this weekend (after the stall, where does soon-to-be Debby go?), but there is some clarity for the next couple of days:

• Saturday: Invest 96L moves into the central Gulf and, by day's end, likely becomes a depression or Tropical Storm Debby. Here at home, it's a day very much like what we saw Thursday and Friday, with scattered showers and storms favoring our western counties by late in the day. Saturday is not a washout, but it is wet, with a 60% chance of showers and storms.
• Sunday: What should be Debby by Sunday begins to intensify over the warm water of the Gulf of Mexico. At the same time, a weak front moving into north Florida doesn't "capture" the storm and pull it east, leaving the low spinning over the central Gulf. However, the system is weak enough that the moisture field is very broad and lots of tropical moisture is pulled in our direction. Plan on more of an all day rain on Sunday with at least 80% coverage of showers and storms, both early and late.

Beyond Sunday, there are lots of question as to where the system goes and it's just too soon to say with any certainty. We generally favor a track that drifts Debby westward into the Gulf but if a second front moving into the southeast is strong enough, it will have the chance to capture the system and bringing it back to the east. We will know much more tomorrow night as the system becomes better organized in the Gulf.

In the meantime, plan on a pretty wet weekend!

Brian Monahan