by Bob Henson and Jeff Masters, Yale Climate Connections
September 21, 2026

The stark contrast between this year’s Atlantic and Pacific hurricane seasons – a direct result of the powerful El Niño event now in progress – will grow even starker this week. Tropical Storm Fay, which popped and surged quickly over the weekend in the subtropical North Atlantic, was already on the wane by Monday. Meanwhile, Hurricane Polo is quickly strengthening as it drifts over torrid waters several hundred miles south of the Mexican Riviera. Polo may approach or surpass the Category 5 threshold by midweek before it embarks on a track set to aim unnervingly close to the Mexican coast.

Despite the thousands of miles between them, both Fay and Polo are drawing on record- and near-record-warm sea surface temperatures for mid-September (see Fig. 1 below). Human-caused climate change made the ocean temperatures along Fay’s path 100 to 200 times more likely, according to Climate Central’s Climate Shift Index.

The rise and fall of Fay, the Atlantic’s latest failed hurricane wanna-be

Fay took shape on Friday in the central North Atlantic southwest of the Azores atop sea surface temperatures around 27 degrees Celsius (82 degrees Fahrenheit). Even at peak season, these waters in this area are typically a touch cooler than the standard 26°C benchmark for supporting hurricane formation, rather than a degree above that threshold. Despite strong wind shear and a relatively dry atmosphere, Fay took advantage of an upper-level sweet spot and the nimbleness of its small size to gain some impressive structure.

Fay’s sustained winds peaked early Monday at 70 mph, just below hurricane strength. Those winds were down to 50 mph by 11 a.m. EDT Monday, as the wind shear and dry air finally began taking their toll. Firmly in the mold of this year’s anemic Atlantic season, Fay is predicted to continue fading, likely becoming a remnant low by Wednesday if not sooner.

With no immediate development projected by the National Hurricane Center for the two days, and just a 20% over the next seven days, the Atlantic’s hurricane “drought” will continue. As we noted in EOTS last week, only three seasons in more than 170 years of Atlantic data have gone past September 21 without a single hurricane: 1905, 1907, and 1914  – and we can’t be sure that every hurricane was caught in that pre-satellite, pre–hurricane-hunter era.

Polo kicks off a new surge of action in an already-frenzied Eastern Pacific season

Rarely if ever does a tropical cyclone organize in such prime conditions as the environment around and ahead of Hurricane Polo. Likewise, the forecasts from the National Hurricane Center (NHC) for Polo are verging on unprecedented territory.

After being designated a tropical depression at 5 p.m. EDT Sunday, Polo was already a tropical storm by 11 p.m. EDT Sunday and a hurricane by 2 p.m. EDT Monday. Veteran NHC forecaster Eric Blake didn’t mince words in his Monday-morning discussion: “Every model responds to these conditions by showing rapid intensification, and the SHIPS rapid intensification index is showing percentages as high as I have ever seen them….Polo is expected to be a small but very dangerous hurricane by tomorrow and beyond.”

Equally sobering was NHC’s official forecast, which brought Polo from a strong tropical storm (65 mph) at midday Monday to Category 5 strength (top sustained winds of 160 mph) by midday Wednesday. Such a forecast must be taken seriously, since we know this ocean basin can support intensification at an even more blistering pace. In 2015, Hurricane Patricia vaulted from tropical storm to Cat 5 in just 24 hours, and in 2023, the peak sustained winds of Hurricane Otis went from 70 mph to 160 mph in a mere 12 hours as the storm approached the Mexican coast south of Acapulco.

At midday Monday, Polo already had a rapidly organizing core of showers and thunderstorms (convection) surrounded by intense banding. Wind shear will be light to moderate (5-10 knots) through midweek within a moist midlevel atmosphere (relative humidity around 70 percent), and Polo will be traversing surface water close to 31°C (88°F), with moderately high oceanic heat content. All these factors will help boost Polo. At midday Monday, the SHIPS statistical model gave Polo an 84% chance of becoming a Category 3 storm by midday Wednesday. These odds are more than 14 times higher than one would expect from long-term climatology.

Track forecast for Polo

Through late Tuesday, Polo will carve out a slow, tight counterclockwise loop well off the Pacific coast of Mexico. Models are in close agreement that Polo will then accelerate northwestward, likely passing close to the Mexican coast on Thursday but perhaps angling enough westward to avoid a direct landfall. Still, residents from Acapulco to Mazatlan should stay vigilant, as only a small rightward angle could be enough for Polo to bring significant impacts to the coast. A tropical storm watch was in effect Monday from Tecpan de Galeana to Punta San Telmo.

The uncertainty level will ramp up notably toward the weekend and into early next week. Long-range models suggest that steering currents will likely push Polo on a more north-northwest track by that point, and that could bring Polo into Baja California and push a surge of moisture toward northwest Mexico and the southwest United States.

Complicating the track forecast is Tropical Storm Odalys, which formed early Sunday well northwest of Polo and is predicted to become a hurricane by later this week. Models show Odalys and Polo approaching each other by Friday and Saturday, with their interaction still difficult to predict at this point.

As soon as this Wednesday, moisture streaming from Polo will join seasonal monsoon moisture to help stoke heavy convection across New Mexico. Widespread 1-2 inch rains and localized totals of  3-5 inches or more could lead to significant flash flooding, especially on Wednesday and Thursday. Days of flash flooding across the Navajo Nation have already taken three lives over the last week.

Nor’easter to bring coastal flooding to the Mid-Atlantic and Northeast

The season’s first extratropical coastal storm (a “nor’easter”) is expected to develop off the coast of North Carolina on Wednesday, then move slowly northeastward toward New England. There is a large discrepancy in the models on exactly where this storm will track and how strong it will get, but it is likely to bring moderate to major coastal flooding to the mid-Atlantic coast on Wednesday and Thursday, with a similar threat developing for the Northeast Thursday through Saturday.

The current forecast from NOAA for Wednesday (Fig. 3 below) calls for major coastal flooding in Virginia’s portions of Chesapeake Bay, with moderate flooding along portions of the coast of North Carolina, Maryland, New Jersey, and Delaware. The National Weather Service in Wakefield, Virginia, is predicting that on Wednesday night and Thursday, offshore winds could increase to 40 mph, gusting to 50 mph, with seas building to 10-14 feet.

The nor’easter also has the potential to be a heavy rainmaker, with the 6Z Monday forecast from the European model calling for 2-4 inches of rain Friday through Saturday for coastal New Jersey, Long Island, Rhode Island, and Massachusetts. Monday morning model forecasts suggested about a 20% chance that this storm could transition to a named tropical storm late in the week. If it does, its impacts would be about the same as if it had stayed an extratropical storm.

Irene Sans contributed to this post.

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