With almost half of hurricane season still left, only four names are left on the conventional name list before forecasters will turn to a special supplementary list for naming storms:
While there have been an unusual number of storms, many have been weak and short-lived. In terms of the total energy generated by storms this year, the Atlantic is only running about 16 percent ahead of average, according to data from Colorado State University.
The approach to October ordinarily marks the transition from “Main Development Region” cyclones, or storms that form over the open waters of the tropical Atlantic, to threats that gel over the Caribbean and Gulf of Mexico. It reflects a seasonal uptick in wind shear, or change of wind speed and/or direction with height, over the central Atlantic that proves hostile to tropical development. But conditions remain favorable for storm development closer to the United States and Central America.
Many October storms in recent years, including Category 5 Hurricane Michael in 2018 and Hurricanes Delta and Zeta in 2020, have taught the United States to never let its guard down during the month.
Tropical Storm Peter
Tropical Storm Peter formed late Saturday well northeast of the Leeward Islands after struggling to take advantage of a rather favorable atmospheric setup. It struggled for days to get its act together, only earning a name after it was three-quarters of the way across the Atlantic.
Peter was called “disheveled” by the Hurricane Center on Sunday, a statement that matches the system’s haggard appearance. For days, the festering tropical wave had meandered west across the Atlantic lacking sustained deep convection, or long-lived tall shower and thunderstorm activity.
At long last, it was named Saturday night. Located about 170 miles northeast of the northern Leeward Islands as of 11 a.m. Monday, the system was drifting west-northwest at 15 mph. It had maximum winds of 50 mph, but should fully avoid the Lesser Antilles as it curves northward out to sea.
On satellite, it was obvious that Peter was struggling — an orphaned low-level center remained exposed from above, divorced from the system’s cluster of thunderstorm activity well to the east. Aircraft reconnaissance, unsurprisingly, found all of the tropical storm-force winds coincident with the heavier thunderstorms to the east, where precipitation was helping drag down momentum from aloft.
Peter will remain harmlessly out to sea, maintaining strength briefly before gradually weakening as it churns north toward Bermuda. By then, it will probably be a leftover tropical depression, through some breezy squalls could enter the vicinity over the weekend.
Tropical Storm Rose
Trailing Peter is Tropical Storm Rose, which was located 620 miles west-northwest of the Cabo Verde Islands on Monday morning. The storm had winds of 40 mph and a narrow window for minor intensification, but weakening was expected by Tuesday as the system quickly degenerates into a tropical depression.
On satellite, Rose looked healthy. Both north and south of the center, transverse banding, or strips of cirrus clouds radiating away from the storm’s center, marked outflow exiting the storm. That’s integral to evacuating “spent” air, allowing for more warm, moist air to enter the storm’s base. It was also roiling with strong thunderstorms.
While ocean water temperatures are sufficiently warm for Rose to maintain strength, wind shear was pernicious and expected to become even stronger. That means Rose’s life span will be rather short, with the system set to wither into a depression by Wednesday.
The Hurricane Center appeared to be having a good time forecasting Rose, opting for a lighthearted bout of humor in its morning discussion.
“There are a lot of thorns in the way of Rose blossoming,” the discussion read. “Thus Rose has about a day to flower into a moderate tropical storm. … At longer range, stronger shear and dry air should pull the petals off Rose one-by-one, causing the cyclone to slowly weaken.”
Other systems to watch
Also in the Atlantic is a tropical wave west of Guinea and Sierra Leone, which is pegged with a 70 percent chance of development. It’s heading west and will probably become a named storm by the end of the workweek. The system already has more convection near its core than Peter.
Weather models indicate it will keep trekking west and intensify, but will probably curve out to sea. Between seven and 10 days out, it’s something that Bermuda will have an eye on; where it makes its sharpest right-hand turn will hinge on the exact position of a high pressure zone over the Atlantic.
Meanwhile, the nontropical remnants of Tropical Storm Odette have become a strong nor’easter in the North Atlantic southeast of the Avalon Peninsula of Newfoundland. They’ll remain well offshore, but could acquire subtropical characteristics as they pass over slightly milder ocean waters. There’s a roughly 1 in 3 chance of subtropical development.
The name “Sam” is next up on the shrinking list.
Jason Samenow contributed to this report.