After a short break, the next Atlantic hurricane, Ernesto, slams Bermuda this weekend. A Category 2 storm, Ernesto, is expected to bring a prolonged period of strong winds and storm surge to Bermuda; the threat will gradually diminish through Saturday night.
After Sunday, the system will accelerate toward the open Atlantic over the Gulf Stream and gradually transition into an extratropical storm south of Newfoundland.
Ernesto will continue as a post-tropical storm and reach Ireland and the UK next week.
Hurricane Ernesto slams into Bermuda with damaging winds and torrential rainfall
Maximum sustained winds remain near 100 mph (155 km/h) with higher gusts. Some gradual weakening is forecast over the next day or so, though some re-intensification is possible by early next week before Ernesto transitions into an extratropical cyclone.
Ernesto is a large tropical cyclone. Hurricane-force winds extend outward up to 75 miles (120 km) from the center, and tropical-storm-force winds extend outward to 275 miles (445 km).
The animation below represents current Ernesto satellite activity throughout multiple channels: infrared, visible, and water vapor scans before landfall and crossing Bermuda on Saturday.
A hurricane warning remains in effect for the island, as tropical storm-force and hurricane-force winds are already being observed.
Heavy rainfall associated with Ernesto is impacting Bermuda through Saturday and will lead to considerable life-threatening flash flooding, especially in low-lying areas on the island.
The attached chart below shows that around 8-10 inches of rainfall is forecast across Bermuda on Sunday.
Even though Ernesto is forecast to remain well offshore on the U.S. East Coast, swells generated by the hurricane are expected to affect the area over the weekend. If advised by lifeguards, beachgoers should be aware of a significant risk of life-threatening surf and rip currents and stay out of the water.
Atlantic hurricane season 2024
During an average tropical year, the Atlantic hurricane season produces up to 14 named tropical storms. On average, seven typically become hurricanes. Three of those reach the major strength (hurricane of a Category 3 or greater).
A typical Atlantic hurricane season has two peaks. The first period of increased activity occurs from early through mid-September, while the second boost typically happens through mid-October. Statistically, the general increase in activity across the tropical Atlantic typically begins in the trough early/mid-August.
So far this year, there have been 5 tropical storms and 3 hurricanes, one of which was a major hurricane. This was a Category 5 Beryl, which devastated the Windward Islands in early July. The hurricane season is forecast to significantly ramp up in the coming weeks.
The seasonal forecasts from the Colorado State University (CSU), led by Dr. Phil Klotzbach, hint at 23 named tropical systems, with eleven hurricanes and five major storms forecast for hurricane season 2024. That’s well above the 30-year average. Based on the long-term average, a hurricane season typically brings 14 named storms, seven hurricanes where three reach a major intensity (Category 3 or greater).
Note that hurricane development is a particular formation in the tropical region. It is susceptible to atmospheric conditions at a given time. The MJO mentioned above wave strongly influences the state of the atmosphere, thus allowing tropical storms or hurricanes to develop.
These systems usually require a hot sea temperature (26 °C or above), very high moisture, and low vertical wind shear through the atmosphere. The tropical wave helps develop a surface low-pressure system.
When these ingredients come together, a tropical cyclone could quickly become a hurricane or even a violent, major hurricane of a greater than Category 3 strength. This happens when all the required conditions are near perfect.
Unlike the mid-latitudes, the tropical region has no warm or cold fronts. Weather activity generally combines showers and thunderstorms with larger-scale pressure and wind variability. Most tropical variability is driven by invisible wave-like features in the atmosphere worldwide.
The two most essential waves are the MJO and Kelvin waves. These two are the second and third most needed ingredients after the warmth of the oceanic waters, respectively.
Much warmer-than-average temperature continues over the North Atlantic Basin
These so-called marine heat waves are becoming more frequent and intense in recent years. This year, they are more persistent and spread over large areas, aligned with global overheating climate and seas. It is hard work to find near-normal or colder spots of the Atlantic this year.
Sea temperatures across the Caribbean and especially the Gulf of Mexico are extremely hot, 31-32 °C across a large part of the gulf. This is becoming a great concern for potential storms that may track into this source of high ocean heat during the peak of the hurricane season in September and October.
The tropical central and western Atlantic regions remain well above normal as we enter the final month of meteorological summer 2024. This correlates well with what is typically seen before active Atlantic hurricane season. The near-term SST anomaly forecast also hints that temperatures will remain very high through the fall months.
We expect the North Atlantic’s sea waters to be sufficiently warm to support significant tropical development during the peak of the hurricane season from late August into September this year.
During the summer months, we closely monitor Western Africa’s weather conditions. This is where the tropical waves emerge into the eastern Atlantic Ocean. Data shows that nearly 85% of these waves lead to organized deep convection over the warmer oceans and become tropical depressions or storms.
Next, Ernesto heads towards Europe and reaches Ireland and the UK as an extratropical cyclone next week
The National Hurricane Center forecasts Ernesto to remain a Category 1 or 2 hurricane through Monday afternoon, gradually weakening while transitioning into an extratropical storm around Tuesday.
The system will also accelerate towards the open North Atlantic after Monday.
Given the supportive high ocean temperatures along Ernesto’s track, the system will remain intense over the Atlantic and likely grow larger in size next week, which is a typical occurrence after a transition into an extratropical storm occurs.
The chart below hints at the potential track across the Atlantic and its corresponding intensity (right chart).
Below is an impressive wind gust accumulation swath map from the ECMWF global weather model over the next 10 days. It shows that hurricane strength remains around the south of Nova Scotia and Newfoundland.
The system then maintains tropical-storm-force strength while crossing the North Atlantic and will reach western Europe by late next week. Models also hint that the remnants of Ernesto could merge with a larger North Atlantic storm before their winds slam into Ireland and the UK.
It’s hard to forecast how intense the extratropical system will be once it reaches western Europe, as it’s about seven days away. However, the general weather model consensus hints that winds at 70-80 mph and high swell and waves late next week are possible.
The most likely track will bring ex-Ernesto near Ireland and Scotland around Thursday and Friday.
Safety Preparedness during a Hurricane Season
Have a plan
The official hurricane season in the North Atlantic and the Caribbean starts on June 1st and ends on November 30th. This is when you and your family must be prepared by planning.
- Write emergency phone numbers and keep them on the refrigerator or near every phone in your house. It would help if you also programmed them into your cell phone.
- Prepare an emergency supply kit.
- Locate the nearest shelter in your area and different routes from your home in an emergency. If shelter locations in your area have yet to be identified, learn how to find them before the event of a storm.
- Pet owners: Take care of your pets at pre-identify shelters, a pet-friendly hotel, or an out-of-town friend or relative where you can take your pets in case of an evacuation. Local animal shelters can offer advice on what to do with your pets if you are asked to evacuate your home during a hurricane.
Learn the difference between a hurricane “Watch” and “Warning”
When you listen to the National Weather Service alerts on TV or radio or check for them online, there are two kinds of alerts:
- A hurricane watch means hurricane conditions (sustained winds of 74 miles per hour [mph] or higher) are possible in a stated area. The National Hurricane Center (NHC) will announce hurricane watches 48 hours before they expect tropical storm-force winds (sustained winds of 39 to 73 mph) to start.
- A hurricane warning is a more severe threat. This means that hurricane-force winds are expected in a stated area. NHC issued these warnings 36 hours before tropical-storm-force winds were expected in the area to give people enough time to prepare for the storm.
Check out the National Weather Service’s Hurricane Center for more information about hurricane watches and warnings. If you hear a hurricane watch or warning in your area, you can take steps to get ready.
Get your car ready to leave home if needed
Make sure your car is ready before the tropical storm or hurricane hits.
- Fill the gas in your car’s tank.
- Move cars and trucks into your garage or under cover.
- Always keep an emergency kit in your car.
If you don’t own a car, consider making plans with friends and family or call authorities to get a ride if you need to evacuate.
Get your family and pets ready
- Go over your emergency plan with your family; understand everything.
- Keep checking for weather updates about the storm. You can watch TV, listen to the radio, or check the NHC website online.
- Call the hospital, public health department, or the police about special needs. If you or a loved one is older or disabled and won’t be able to leave quickly, get their advice on what to do.
- Put pets and farm animals in a safe place.
Get your home ready
- Clear your yard to ensure nothing could blow around during the storm and damage your home. Move bikes, lawn furniture, grills, propane tanks, and building materials inside or under the shelter.
- Cover up house windows and doors. Use storm shutters or nail pieces of plywood to the outside window frames to protect your windows. This can help keep you safe from flying debris and pieces of shattered glass.
- Be ready to turn off your power if you see flooding, downed power lines, or you have to leave your home. Switch your power off completely.
- If you lose your water supply during the storm, fill clean containers with drinking water. You can also fill your sinks and bathtubs with water for washing.
- Double-check your carbon monoxide (CO) detector’s battery to prevent CO poisoning.
Be ready to evacuate or stay at home
During a hurricane warning, always listen to authorities regarding whether you should evacuate or stay home.
If a hurricane is coming, you may hear an order from authorities to evacuate (leave your home). Never ignore an order to evacuate. Sturdy, well-built houses may not hold up against a hurricane’s power. Staying home to protect your property is not worth risking your family’s health and safety.
There are occasions when you may hear an order to stay at home. If driving conditions are too dangerous, staying home might be safer than leaving. Respect the authorities’ decisions.
If you need to evacuate:
- Grab your emergency supply kit and only take what you need (cell phone, chargers, medicines, identification like a passport or license, and cash).
- Unplug your appliances. If you have enough time, turn off the gas, electricity, and water.
- Follow the roads emergency workers recommend, even if dense traffic is expected. Other routes might be blocked or already flooded. Never drive through flooded areas, as cars and other vehicles can be swept away or may stall in just 6 inches of moving water.
- Contact your local emergency management office and ask if they offer accommodations for owners and pets.
If you need to stay home:
- Keep your emergency supply kit anywhere where you can easily access it anytime.
- Follow weather updates online from NHC, and listen to the radio or TV for updates on the hurricane.
- Stay inside. Even if it looks calm, don’t go outside. Wait until you hear an official message that the hurricane is over. Sometimes, the weather gets calm in the middle of a storm but then quickly worsens again.
- Stay away from windows. You could get hurt by flying debris, such as pieces of broken glass or other objects picked up by winds around the neighborhood during the storm. Stay in a room without windows or go inside a closet.
- Be ready to leave home. If emergency authorities order you to leave or your home is severely damaged, you may need to go to a shelter or a neighbor’s house.
Our expert forecaster team will actively follow the tropical region activity worldwide, including Atlantic Basin systems and tropical cyclones likely to affect the United States, the Caribbean, and Europe again in the following months.
Stay tuned for further follow-up posts, in-depth forecast discussions, and nowcasting during the coming weeks and throughout the upcoming Atlantic hurricane season 2023 peak months. We will prepare you.