Jeff Masters Weather Blog

Windward Islands bracing for potential hurricane hit on Monday » Yale Climate Connections

Tropical Depression Two formed over the near-record warm waters of the central tropical Atlantic at 5 p.m. EDT Friday. TD 2 is expected to intensify into Hurricane Beryl before moving through the Lesser Antilles on Sunday night and Monday. Hurricane strikes this early in the season are virtually unheard of in the Lesser Antilles; the only tropical cyclones to form farther to the east of TD 2 in June were tropical depressions in 2000 and 2003 that died in the central tropical Atlantic without achieving tropical storm strength.

As of 5 p.m. Friday, TD 2 was located about 1,225 miles east-southeast of Barbados in the Windward Islands, moving west at a brisk 17 mph. Satellite images showed heavy thunderstorms covered an large and expanding area around the system, with banded features continuing to develop.

Because of limited fuel supply for long flights, hurricane-hunter aircraft typically do not probe systems eastward of about 50° west longitude in the North Atlantic. As a result, the first two reconnaissance flights scheduled for TD 2 are for early Sunday morning. Forecasters will thus have to rely even more than usual on satellite data to assess TD 2’s development between now and then.

Forecast for TD 2

Conditions in the Main Development Region of the tropical Atlantic, from the Caribbean to the west coast of Africa, are unusually favorable for the final days of June (see Tweet above). As TD 2 approaches the Windward Islands, sea surface temperatures will be near-record warm, about 28-29 degrees Celsius (82-84°F), wind shear is predicted to remain mostly in the light range, 5-10 knots, and the atmosphere will be moist, with a mid-level relative humidity of 65-70%.

TD 2 has been embedded in the Intertropical Convergence Zone (ITCZ) this week and has stayed relatively close to the equator, around 9°N. These factors kept development gradual through Friday. However, TD 2 will be gaining latitude over the weekend and its circulation should begin to pinch off from the ITCZ. A large area of dry air associated with the Saharan Air Layer (SAL) lies to the north, but it now appears the envelope of moisture forming around TD 2 may fend off the dry air as the system approaches the Windwards.

Forecast models are in close agreement on TD 2 continuing west to west-northwest and tracking through the Windwards on Sunday night and Monday. In their 18Z forecasts issued at midday Friday, NOAA’s four higher-resolution forecast models, which are designed largely for intensity guidance, all predicted TD 2 to become a hurricane on Saturday or Sunday, then pass through the Windward Islands at anywhere from Category 1 to Category 4 strength. Barbados, St. Vincent and the Grenadines, Grenada, and St. Lucia are all likely to experience impacts, with NHC predicting 3-6 inches of rain over these islands. Significant wind damage is likely near and to the right of where the eye tracks.

After moving through the islands, TD 2 is projected to continue into the eastern Caribbean. There remains disagreement among operational and ensemble track models on whether TD 2 will then curve west-northwest toward the Greater Antilles or continue on more of a westward track toward Central America and Mexico. Hurricanes often – but not always – weaken while moving across the eastern Caribbean during early July, due to wind and circulation features that are typically unfavorable. Much will depend on how TD 2 evolves in terms of size and strength and what if any interaction with the islands it ends up having. In general, a stronger and earlier-developing storm would be more likely to take a more west-northwesterly track, threatening the northern Caribbean islands, while a weaker and slower-developing storm would be more likely to track due west.

The last hurricane to form during June in the Main Development Region was the destructive Trinidad hurricane of 1933, almost a century ago. That year was a barn-burner of an Atlantic hurricane season – still the most active on record, going back to 1851, in terms of accumulated cyclone energy (ACE).

Watching a possible sequel to 95L in the eastern Atlantic, and a potential quick spin-up in the Bay of Campeche

Longer-range runs of the GFS and European models indicate that another tropical wave, this one in the eastern Atlantic and moving quickly westward behind TD 2, could develop early next week as it approaches the Lesser Antilles, perhaps reaching the islands around Wednesday. There was ample support for this system among the GFS ensemble members, with somewhat less support in the Euro ensemble. Such development could be inhibited by the proximity of TD 2, depending on the evolution and ultimate tracks of both systems. In their 8 p.m. EDT Friday Tropical Weather Outlook, the National Hurricane Center gave this system 2-day and 7-day odds of development of 0% and 40%, respectively.

Meanwhile, a tropical wave designated 94L in the far northwest Caribbean could still organize briefly this weekend after it crosses the Yucatan Peninsula and moves into the Bay of Campeche, on a track roughly similar to that of Tropical Storm Alberto, which hit northeastern Mexico on Jun. 19. A number of the GFS and European ensemble members from early Friday develop 94L into a tropical depression or weak tropical storm on Sunday before a projected landfall in northeastern Mexico by Monday morning. A hurricane-hunter mission into 94L tentatively set for Friday afternoon was cancelled. In their 8 p.m. EDT Friday Tropical Weather Outlook, the National Hurricane Center gave 94L 2-day and 7-day odds of development of 40%. The actual window of potential development is quite narrow, mainly between early Sunday and Monday.

The next three names on the Atlantic list of storms are Beryl, Chris, and Debby. The 2024 hurricane season got off to its slowest start since 2014 on Jun. 19, when Tropical Storm Alberto formed. The typical formation date of the season’s first named storm is Jun. 20, and the second, Jul. 17. The record-earliest formation date of the season’s second named storm came on May 16, 1951, when Tropical Storm Able formed.

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