Rafael predicts hurricane will hit Cayman Islands and Cuba » Yale Climate Connections

Hurricane warnings are in effect for the Cayman Islands and western Cuba for Tropical Storm Rafael, which formed over the warm waters of the western Caribbean on Monday at 5 p.m. EST. Rafael is expected to strengthen into a Category 1 hurricane Tuesday evening, triggering hurricane conditions in the Cayman Islands this evening and western Cuba on Wednesday.

Rafael's formation results in 17 named storms, 10 hurricanes, four major hurricanes, and an accumulated cyclone energy index (ACE) of 148 (26% above average) for the 2024 Atlantic hurricane season. In an average season, there are 14 named storms, seven hurricanes, three major hurricanes, and an accumulated cyclone energy index (ACE) of 117.

Rafael is still in the organizing phase

At 10 a.m. EST on Tuesday, November 5, Rafael was 200 miles (320 km) east-southeast of Grand Cayman and moving northwest at 13 mph (20 km/h), with peak winds of 60 mph (95 km/h) sustained a central pressure of 994 mb. Cayman Islands radar showed Rafael bringing heavy rain showers to Jamaica and the Cayman Islands. A personal weather station about 10 miles west of Kingston, Jamaica, recorded 3.54 inches (90 mm) of rain in the nine hours ending at 11 a.m. EST on Tuesday.

Satellite images showed that Rafael had a modest number of severe thunderstorms that were becoming more organized, and that the storm may have begun to build an eyewall and develop an inner core. Conditions were very favorable for development: light wind shear of 5-10 knots, a very humid atmosphere and very warm sea water of 30 degrees Celsius (86°F) – about 0.5 to 2 degrees Celsius (1-2°F) . warmer than average for early November. The Caribbean as a whole is on the verge of record warm levels for this time of year, roughly comparable to 2023 and well above other previous years, according to analyzes of sea surface temperatures by the University of Arizona.

Forecast for Rafael in the Western Caribbean

A ridge of high pressure northeast of Rafael will keep the storm on a mostly northwesterly track through Thursday, reaching the center of the storm about 40 miles (80 km) west of the western tip of Jamaica around 2 p.m. EDT Tuesday afternoon. then between Grand Cayman and Little Cayman Islands around 11pm on Tuesday.

Rafael is expected to make landfall in western Cuba on Wednesday morning. Landing in Cuba is expected to provide very favorable conditions for development, with light wind shear, warm water with high heat content and a very humid atmosphere. This will likely result in steady to rapid intensification, with Rafael near a Category 1 hurricane in the Cayman Islands this evening and near Category 2 hurricane strength near western Cuba on Wednesday morning. The 6Z Tuesday runs of the dynamic hurricane models HWRF, HMON and HAFS-A predicted that Rafael would be a borderline Category 1 or 2 hurricane on Wednesday morning, while the HAFS-B model was more aggressive, predicting a Category 3 landfall on Cuba. The 12Z Tuesday SHIPS model gave a 29 percent chance that Rafael would quickly strengthen to a Category 1 with winds of 85 mph by Wednesday morning, when the storm would hit western Cuba.

Rafael's influence on Cuba: a major threat to electricity supply

Rafael is expected to land in Cuba at an inopportune time as the island's power grid continues to suffer instability following a nationwide blackout from October 18 to 21 caused by the failure of the Antonio Guiteras power plant, Cuba's largest power plant suffers. According to the National Hurricane Center's latest forecast, Rafael will maintain hurricane strength as it passes over western Cuba, with the center located about 30 miles (50 km) west of the capital, Havana (population 2.1 million). This track would place the city into the dangerous right front quadrant of the storm, resulting in severe wind damage. Cuba's electrical infrastructure is so weak that the large number of power outages likely to occur in western Cuba could be prolonged and the country's entire power grid could be at risk of collapse.

Rafael expected to be torn apart in the Gulf of Mexico

Passage over western Cuba will likely cause some disruption to Rafael, but once the storm reaches the Gulf of Mexico, it is expected to move northwest across an associated tongue of warm waters of 27 to 28 degrees Celsius (81 to 82 °F). with the Loop Current extending from the western Caribbean north to the central Gulf of Mexico. All four high-resolution dynamic hurricane models place Rafael in the central Gulf at least as a Category 2 through Thursday.

There is much uncertainty surrounding the strength and positioning of an upper-level low over the central U.S. that will guide Rafael later this week, and the National Hurricane Center commented in its discussion at 10 a.m. EST that the forecast for Rafael over the Gulf is higher Uncertainty than usual. The GFS model and its ensemble members predict continued northwestward movement for Rafael, with the storm approaching Louisiana by the end of the week. However, the UKMET model and the European model and its ensembles support a westerly turn in the Gulf, well south of the northern Gulf Coast (Fig. 2).

Regardless of Rafael's eventual route in the Gulf, the storm is expected to be torn apart late this week by strong wind shear combined with dry air, and most models predict that Rafael will not make landfall in the U.S. as a tropical storm. Recurring fall cold fronts have spread cool air across the Gulf in recent weeks, causing the water to cool significantly. Waters within about 200 miles (320 km) of the northern coast of the Gulf of Mexico have cooled to below 26 degrees Celsius (79°F). More importantly, the jet stream has shifted more southward in recent weeks and therefore Rafael will encounter strong wind shear of 20 to 30 knots as it approaches the US coast. Additionally, very dry air is expected over the central and northern Gulf late this week with a mean relative humidity of 45-50%.

There is a possibility of heavy rainfall over the southeastern United States due to a movement of moist air in advance of the storm, as Rafael is located in an area of ​​unusually high humidity for early November. The National Weather Service has placed much of Georgia and southwestern South Carolina in its “slight risk” area for excessive rain Wednesday, and three to five inches of rain could fall there, with locally higher amounts.

Another disturbance could spread across the Bahamas toward South Florida later this week

The tail of a cold front in the northwest Atlantic may attempt to form into a tropical disturbance late this week, spreading over the southeastern Bahamas on Friday and then moving west-west-northwest toward southern Florida. Some members of the European model ensemble and most members of the GFS model ensemble show the development of this disturbance into a tropical depression or a weak tropical storm. There is relatively high confidence in the steering pattern and sea surface temperatures remain unusually warm – more than sufficient to support a tropical cyclone. However, upper level wind shear and wind structure are not ideal.

In its Tropical Weather Outlook at 7 a.m. EDT Tuesday, the National Hurricane Center gave this future system a 20 percent chance of developing into at least a tropical depression within seven days, with a near-zero chance in the two-day window .