Hurricane forecasters keep eye on developing storm, to be named Helene, in Caribbean

The National Hurricane Center is monitoring the western Caribbean for the formation of what is expected to become Tropical Storm Helene — and then Hurricane Helene — midweek.

Threat level: With record-warm Gulf waters, the storm is forecast to rapidly intensify into a Category 3 hurricane before hitting Florida's big bend region Thursday.

• "The storm surge, wind, and rainfall impacts will extend well away from the center, particularly to the east of the system," the National Hurricane Center noted late Monday.
• This would likely include Tampa Bay, which is especially vulnerable to storm surge flooding, as is the big bend region, where the peninsula curves into the panhandle, and parts of south and southwest Georgia.
• Based on its current projected track it poses a significant high wind and heavy rain threat to Tallahassee.
• The storm would likely extend its impacts to surrounding states including Mississippi and Alabama, though track details will become clearer once a cohesive storm center develops on Monday or Tuesday.
• "In addition, the fast forward speed while it crosses the coast will likely result in farther inland penetration of strong winds over parts of the southeastern United States after landfall," the NHC said.

Zoom in: The weather agency noted in a forecast discussion Monday evening that there is likely to be a period of rapid intensification of the storm from when it forms into a tropical depression, with maximum sustained winds of 35 mph, and when it hits land as a major hurricane.

• Multiple computer models are flagging the rapid intensification potential, due to the abundance of warm waters and atmospheric conditions conducive to significant strengthening.
• The NHC forecast discussion noted its projection calls for maximum sustained winds to potentially jump by as much as 75 mph over a 72-hour period between Tuesday and Thursday.

State of play: Florida Gov. Ron DeSantis declared an emergency in 41 counties ahead of the expected arrival of the storm.

• A tropical storm watch was in effect along the southwest coast of Florida, from Bonita Beach southward to Flamingo overnight.
• A storm surge watch was issued along the southwest coast of Florida from Bonita Beach to Flamingo.

The big picture: The Atlantic hurricane season was forecast to be hyperactive due to record warm ocean temperatures and the formation of a La Niña event in the tropical Pacific Ocean. However, other factors have stifled storm activity for long periods.

Yes, but: It only takes one significant storm to make for a damaging and memorable season.

• While the intensity of what is expected to become tropical storm and then Hurricane Helene is subject to uncertainty, it has the potential to be significant and destructive.

Context: Climate change is boosting global ocean temperatures, which were at record-high levels for more than a year straight.

• There has been a documented trend toward more storms that rapidly intensify, and an amplification of the intensification rates in some ocean basins, including the Atlantic.

Go deeper: Hurricane John makes landfall in Mexico as Category 3 storm

Editor's note: This article has been updated with more details on the forecast and Florida's response to the threat.