FLHurricane.com: Ian Lounge

Invest 98L's surface center has arguably remained more over northernmost South America, than over the Caribbean, and this land interaction coupled with debilitating outflow from Hurricane Fiona have been preventing the trof from developing, thus far. However, with the continued pull to just north of west, along with Fiona moving away, the likelihood of tropical cyclogenesis is easily pegged at 70% within 2 days and 90% within 5 days.

But we have questions.

It appears that many models have initialized 98L a little too far over open water. This may result in a rightward track bias. There remains a possibility that 98L tracks further west than currently advertised by whatever consensus currently exists. This is not a baseline scenario, but can not be ruled out.

Additionally, operational GFS this season has proven to have a high development and intensification bias in the western Caribbean. Unsurprisingly, even early runs of GFS on 98L have predicted a sub-940hPa Major. While definitely far more realistic a possibility than earlier in the season, one could say likely, it does yet cast doubt on the aggressive runs GFS has put out so far, and also puts even more into question the forecast of a more right-leaning track, including the Florida peninsula, as a less robust cyclone may not pull so far to the right. Even if the system were to Major, if it doesn't major soon enough, this could still be more of a concern from Texas to the Florida panhandle than the Florida peninsula.

Realistically, this far out and without a solid cyclone yet to forecast off of, even Mexico is still in play, however unlikely.

These caveats aside, the baseline and more likely outcome is for the fledgling to really take off somewhere between the central and western to northwestern Caribbean in an environment of moderate to very low shear and high to very high ocean heat content, with long-range modeling still suggesting a tug into the central to eastern Gulf of Mexico.

Some Sep 22 0z runs
GFS - May have a reasonable initialization. Probably TD by late Thursday night/Friday morning. Tropical storm by Saturday night while in the central Caribbean. Hurricane by Monday morning in the northwestern Caribbean. Cat 2 or better on approach to northeastern/eastern Yucatan Tuesday morning (the 27th). Crosses northern Yucatan during the day Tuesday as high-end Tropical Storm to Hurricane. Becomes a sizeable and powerful Cat 2+ hurricane in the central Gulf mid to late next week on approach to Louisiana, with a landfall in central Louisiana early Sunday, October 2nd.

HMON - Looks to have initialized too much over open water. TD by later this morning or early afternoon (Thursday, 22nd). Tropical Storm by Sunday morning while in the west-central Caribbean. Hurricane by Monday morning in the northwestern Caribbean. End of this model's run as a Cat 2 on approach towards the northeastern Yucatan.

HWRF - Initialized a bit much northeast, over water and already organizing. Tropical Storm as of this hour in the extreme southern Caribbean, with the cyclone then seeming to struggle until it reaches the west-central Caribbean. Hurricane by midday Sunday in the western Caribbean. Majors in the northwestern Caribbean Monday morning. Cat 4 by Monday night. Deepening Cat 4+ near 20.5N 85W at the end of this model's run predawn Tuesday the 27th.

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