The National Hurricane Center warned Monday that a low-pressure system in the southwestern Gulf is organizing and will likely become a tropical depression during the middle or latter part of the week, drifting toward the U.S. Gulf Coast.
In its Monday morning outlook, the NHC said a trough of low pressure in the southwestern Gulf is producing disorganized showers and thunderstorms. Environmental conditions are only "marginally conducive," but gradual development is becoming more likely. The official numbers: a 30% formation chance through 48 hours, rising to 70% through seven days — with some later updates pushing the seven-day odds to 80%.
Models have been sniffing around this area for days, and the NHC has designated the system Invest 92L, meaning future advisories will include tracking maps and spaghetti models. If it earns a name, it would be Isaias — pronounced ees-ah-EE-ahs — the ninth named storm of the Atlantic season.
Forecasters broadly agree on the steering: the system drifts eastward over the next few days, then turns northward toward the U.S. Gulf Coast. Meteorologist Matt Lanza of TheEyewall.com said a track north or northeast seems reasonable, "putting Louisiana through Florida on some notice — not likely Texas."
The highest-confidence forecast, however, is not about wind. "I think what we are most confident in at this point is a heavy rain event for the Gulf Coast and Florida," Lanza said.
AccuWeather's outlook puts numbers on it: the most likely intensity is a tropical depression or tropical storm, with only a 15% chance of reaching hurricane strength. But the rainfall could be serious — four to eight inches across the northern Gulf, from New Orleans to the Florida Panhandle. Impacts could begin as early as Friday as a surge of tropical moisture brings heavy rain and flooding risks through the weekend.
The timing is bad. The Florida Panhandle just took a soaking this past weekend from an unrelated stalled front: up to 7 inches of rain in some areas, with flash-flood concerns around Tallahassee. The National Weather Service warned that another 6 inches could fall Monday evening. On already saturated ground, additional tropical rainfall raises the inland flooding risk considerably.
This Atlantic season has been unusually quiet: as of 8 a.m. Monday, the basin had produced eight tropical storms and not a single hurricane. Forecasters credit an increasingly potent El Nino, which has been killing embryonic systems and shortening the lifespans of the ones that do form.
That makes this Gulf system a contrarian — developing against a strong El Nino headwind. How far it gets remains uncertain. For Gulf Coast residents, the advice is simple: check the NHC update daily this week. The wind may stay modest, but the rain is coming.