Note, this story was updated at 11am ET on Saturday with key forecast data. The questions highlighted below remain unanswered.

As of Saturday morning, Hurricane Irma is moving westward, with its center just inland over the northern coast of Cuba. It is nearing the western periphery of a ridge of high pressure, which should force it into a northwest turn soon. Although the forecast models have been struggling with precisely when this turn is likely to occur, we have pretty high confidence it will turn west-northwest later today, and then northwest tonight. The Florida Keys will be hit very hard later today and Sunday.

The more westward track over Cuba has weakened the storm’s maximum winds to 125mph, and additional weakening is possible before Irma moves back into the Straits of Florida later today or tonight. This movement will also keep the center of Irma away from the greater Miami area, sparing the heavily populated southeastern coast of Florida from the worst effects of winds and storm surge. Hurricane force wind gusts are still likely, but they will probably not cause widespread damage in Miami.

With that said, Irma remains an extremely dangerous hurricane for parts of Florida, and it should restrengthen tonight and Sunday in the waters between Cuba and Florida. Here are some of the key questions that meteorologists are considering regarding the storm today; the answers will ultimately determine where its most devastating effects occur.

Cuba weakening

Part of Irma's center moved over the northern Cuban coast on Friday night, and this interaction with land weakened the hurricane from 160mph winds to 125mph winds by Saturday morning at 11am ET. Depending upon the storm's movement today, it could spend another 12 to 18 hours over Cuba, or near enough to it, to lead to additional weakening.

The question is, how much? Hurricane intensity models aren't of much use right now. What would really be beneficial for Florida is to see Irma's circulation significantly disrupted today, but for now that appears unlikely because so much of the storm will remain over the very warm waters between Cuba and Florida.

Restrengthening

We'd like to see the circulation disrupted, because after Irma moves back over water it will find favorable conditions for strengthening. Irma will have a period of approximately 24 hours—the timing depends upon where the storm goes, as a more westerly track keeps it over the extreme southeastern Gulf of Mexico for longer—in which to re-organize and intensify.

Some of the global models predict significant intensification at this point, and for now the National Hurricane Center predicts Irma will come ashore along the western or southwestern Florida coast as a major hurricane, with 140mph winds. Frankly, this is a low confidence forecast given the uncertainties discussed above.

Final landfall

Where, ultimately, will Irma come ashore? The operational run of the European model on Saturday morning predicted a landfall along the southwestern coast of Florida, near Fort Myers or Port Charlotte. But given the anticipated north-northwest movement of the storm at this point, the geography of the Florida coast means it is impossible to have confidence in the actual point of landfall.

What seems clear is that the western side of the state, which just a day or two ago had anticipated the Miami area would get hit hardest, now finds itself in the crosshairs of a major hurricane with potentially catastrophic winds and damaging storm surge. The city of Tampa has not suffered a direct hit by a strong hurricane since the 1921 Tampa Bay Hurricane. It now seems plausible that the city will break that streak.

Inland rainfall

Even with the westward shift in Irma's track, much of Florida will still see damaging winds this weekend. However such winds are unlikely to be catastrophic for most of the central and eastern part of the the state. Therefore, for much of Florida, the big concern is likely now inland rainfall.

This is because these areas, including Miami, will be on the right side of the storm's circulation, where the heaviest rainfall bands typically set up. This will not be a Hurricane Harvey situation, where the storm stalls. However, as Irma drifts north along the western side of Florida, it could potentially drop 15 to 20 inches of rainfall across parts of the state.