Another Atlantic Potential Development Area and Polo Reaches Category 5 Near Mexico

IN THE ATLANTIC

Tropical Storm Fay is fading fast. It is succumbing to hostile upper-level winds, and is forecast to be history by tomorrow.

The National Hurricane Center is drawing a potential development area off the African coast. A robust disturbance forecast to move into the Atlantic tomorrow has a chance to develop. The El Niño-driven prohibitive upper winds don't quite reach that corner of the Atlantic, although the atmospheric environment is still marginal.

The National Hurricane Center is putting low odds on the system becoming a tropical depression, but we'll see what happens once it comes across the coastline.

In any case, the consensus of the computer forecast models is that it will turn north and track just offshore of the African coast. There's a chance it will add to the 2026 record book, but preliminarily the only threat appears to be heavy rainfall in Senegal and Mauritania along the West Africa coast.

DEVELOPING NOR'EASTER

It won't be a tropical system, but a consensus is developing that a potential strong, long-duration, early-season nor'easter will develop off the Northeast coast late this week. It will be trapped in an upper-level low, so there won't be steering currents to kick it out quickly. That will mean that the storm, if it develops as forecast, will combine with the astronomical high tides of the Harvest Moon to produce coastal flooding.

The system is just beginning to develop off the Carolinas. Coastal residents from the Mid-Atlantic to New England should stay well informed later this week. The storm could remain near the Northeast coast into next week.

IN THE PACIFIC

Tropical Storm Polo has rapidly intensified into a Category 5 offshore of the southwestern Mexican coast. It's forecast to parallel the coastline as it tracks north this week. Even without making landfall, heavy rain from the outer bands interacting with the Sierra Madre del Sur mountain range along the coast will produce life-threatening rainfall and mudslides where the elevations are steep.

Polo is small in diameter, so there is less of a wind threat, assuming the forecast is correct and the core of the storm stays offshore. The Mexican government has issued a Tropical Storm Watch for the coastline from Manzanillo south, anticipating fringe wind effects from the storm.

At the end of the five-day cone and beyond, the forecast gets iffy. Tropical Storm Odalys is forecast to track reasonably close to Polo well offshore of Baja California. How those storms might or might not interact is impossible to predict at this point.

The bottom line is that everyone on the west coast of Mexico should plan to stay informed of the latest forecast this week and over the weekend.

To Polo's west, Odalys is currently a tropical storm, but it is forecast to reach hurricane strength over the next few days. It doesn't have much potential to be memorable unless it interacts with Polo somehow. We'll see.

Another disturbance has a medium chance of developing into at least a depression just offshore of southern Mexico. Forecasts for undeveloped systems are always uncertain. It's unclear whether the system will make landfall or follow Polo's path offshore. In any case, it's likely to bring heavy rain to parts of Mexico.

Southeast of Hawaii, the Remnants of Tropical Depression 15E are organizing. But the National Hurricane Center gives the system a high chance of regenerating into a tropical depression or Tropical Storm Nolo – the next name on the Central Pacific list.

Indications are that the core of the storm will stay south of Hawaii, but the tropical moisture plume looks likely to spread across the islands beginning late today or tomorrow. Stay aware of any flood alerts issued by the National Weather Service in Honolulu.