On paper, hurricane season ends on Nov. 30, but this season has been far from by-the-books. And looking ahead, it appears the atmosphere may try to get one final word in.
Already, meteorologists are tracking two more “areas to watch” that could be problematic, including near hard-hit Central America. Neither system has a high chance to develop, but their mere presence show that the ocean is not quite done yet.
There may also be a period of conditions mildly conducive to tropical development in the southern Caribbean during the first week or two in December, though with winter coming, we are running out the clock.
Two areas to watch
On Wednesday, the National Hurricane Center in Miami outlined two areas that bear watching for possible tropical development but gave each only a 20 percent chance of becoming a named storm. One system was nestled in the southwest Caribbean, while the other occupied the ocean between the Bahamas and Bermuda.
In the Caribbean, a strip of thunderstorm activity stretched from the shores of northern Venezuela to just south of Hispaniola.
This area of disturbed weather could bring heavy rainfall to portions of Nicaragua, and especially Costa Rica and Panama. Some places, especially in the higher terrain of western Costa Rica and Panama, could see 4 to 8 inches of rain from Friday into Saturday, which could spark flooding. Isolated one-foot totals can’t be ruled out.
In Nicaragua, the rains arrive Saturday into Sunday, with moist flow even yielding sporadic downpours in Honduras, Guatemala and Belize. Rainfall amounts will be highly variable, but renewed flooding is possible in areas that have already seen 30 to 50 inches or more from Hurricanes Eta and Iota.
Meanwhile, a region of low pressure may form between the Bahamas and Bermuda into early next week in advance of an approaching mid-level disturbance over the southern United States. The system will begin as a typical nondescript patch of ocean storminess, but could acquire some subtropical or tropical characteristics as it is swept northeast.
A period of showery and breezy weather is likely Monday into Tuesday in Bermuda as the system passes nearby; it will be simultaneously energized by an atmospheric disturbance. It’s improbable that the system “closes off” into a self-contained storm that earns a name. But, in the unlikely event it does, “Kappa” is up next on the naming list.
An uncertain start to December
In most years, tropical activity wraps up before Halloween. But not this year. There are mixed signals about what may lie ahead, but the oceans at the very least have enough fuel left for one or two final acts.
In the United States, it’s probably safe to say the season is over, and that no more tropical systems are likely to affect the Eastern Seaboard or Gulf Coast. Sea surface temperatures in the Gulf of Mexico and the Eastern Seaboard are still running well above average and could sustain a storm, but the inevitable southward shift of the jet stream will yield harsh wind dynamics that are largely unsupportive.
In the Caribbean and Atlantic, it’s a different story. While there are no immediate signs of any storm potential, we’re firmly in the season where cold fronts can shed a rogue storm or two that manages to take advantage of still-mild seawaters.
Rising motion in the upper atmosphere could kindle any Atlantic or Caribbean disturbance if it was to gain enough gumption, primarily through about Dec. 10. After that, an influx of sinking air, coupled with the cooling waters, should once and for all shut the door on any meaningful storm development.
So until mid-December, any and all Caribbean and southwest/central Atlantic disturbances will have to be watched with scrutiny just as if was September. The atmosphere doesn’t own a calendar, and, as Iota showed when it became the latest-forming Category 5 storm on record early this week, storms care far more about conditions than the time of year.