3 Questions Ahead of Hurricane Season

The 2024 Atlantic Hurricane Season officially began on June 1. We typically see peak hurricane season from mid-August to mid-October with the peak date of September 10.

Each year the National Oceanic and Atmospheric Administration (NOAA) releases its official North Atlantic Hurricane Season Outlook, which highlights the predicted number of storms we will see in the Atlantic and whether they are a named storm, a hurricane, or a major hurricane. It’s important to note not all these storms will make landfall.

Tropical systems go through various phases and progress very slowly if at all, or very rapidly. Here are the phases, and then we’ll tackle the big questions heading into another hurricane season:

• Tropical Depression: A tropical cyclone with maximum sustained winds of 38 mph (33 knots) or less.
• Tropical Storm: A tropical cyclone with maximum sustained winds of 39 to 73 mph (34 to 63 knots).
• Hurricane: A tropical cyclone with minimum sustained winds of 74 mph (64 knots) or higher. Will be labeled as Category 1 or 2 on the Saffir-Simpson Hurricane Wind Scale.
• Major Hurricane: A tropical cyclone with minimum sustained winds of 111 mph (96 knots) or higher, corresponding to a Category 3, 4, or 5 on the Saffir-Simpson Hurricane Wind Scale.

1. What fuels the development of hurricanes?

When it comes to hurricane season, ocean water temperatures are a leading contributor.

As the ocean increases its average temperature, we have a greater likelihood of more hurricanes developing and even stronger hurricanes. Historically, we have tracked the sea surface temperature anomaly to identify year-over-year trends. Last year, we saw record warmth. This year is on pace to stay the same or increase even higher. The sea surface temperatures are one of the main driving factors we are seeing rapid intensification such as Otis last year and this season with Beryl (which is concerning how early in the season it has undergone this).

Beyond water temperature, we also have to consider the diminishing El Niño.

Historically, El Niño causes a wind shear that reduces the development of tropical storms as the winds in the upper levels of the atmosphere tear storms apart, or if they do develop, they are what we call a “fish storm,” meaning it will more than likely turn its course in the open waters and remain in open waters until he fazes out.

When we see the opposite, La Niña, we won’t have that wind shear in place, so hurricanes can be produced easier without that wind shear. The transition to La Niña is anticipated to occur this summer.

2. Are the forecast tools reliable?

There is a wide range of forecast tools that NOAA and local forecast offices use to push out messaging of potential storms and their tracks.

It is very important to rely on professional forecasts as these are the most accurate information you may receive. There are a lot of “backyard forecasters” who will publish future data that is extremely unreliable as all forecasting systems have limitations. It is always recommended to rely on NOAA data or your local NWS office forecast.

One of the most widely known tools you will see during hurricane season is the error cone. The error cone represents the probable track of the center of the tropical system. Keep in mind that the cone only provides an estimate. The center of the storm could lie anywhere within that entire white space of the cone. The cone will also help us identify what type of system is on the horizon. Based on forecasts over the previous five years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60 to 70 percent of the time.

Then, there’s wind speed probabilities. What the graphic will show is the most likely areas that will receive winds of tropical storm force strength and the percent likelihood of that occurring. During Hurricane Sandy, five days before arrival to the New Jersey coast when it was still off the coast of Florida, areas of southeast Pennsylvania were between a 50–60 percent probability to receive tropical storm force winds. 

The earliest arrival time for tropical storm-force winds is another great tool that could be utilized in pre-planning efforts. This will look similar to the error cone but instead show dates and times that the winds are expected to be between tropical storm force strength.

Key message graphics often will be sent via email if your area is anticipated to be impacted by tropical systems. They will usually include several key graphics as well as text information highlighting key predictions or impacts due to the approaching storm.

Finally, there are storm surge maps. Storm surge maps show the areas where inundation from storm surge could occur and how high above ground the water could reach. This is oftentimes a colored map of a coastal area with the colors meaning the forecasted depth of the sea at above ground levels.

A link to all of the graphical products and descriptions can be found at NHC Tropical Cyclone Graphical Product Descriptions.

So what can I do now?

We always stress the importance of being prepared. Continue to monitor the forecasts and be in the know of what is developing in the open waters.

We don’t need to have a direct impact on our areas to feel the impacts of a tropical system. We have seen historically that we may rely on supplies coming from an area that has been directly impacted by tropical systems and as a result, you may face supply chain issues.

Also, support your personal preparedness by ensuring you and your staff are ready at home. Ready.gov is a great resource for identifying important items to have at home to be prepared for the potential impacts of tropical systems. In the northeast, we are not exempt from tropical weather due to our proximity to the Atlantic Ocean states and due to weather tracking up the coast from Florida or from the Gulf of Mexico. Often times these remnants can bring with them strong winds and large amounts of rainfall even though they are not a hurricane or even tropical storm any longer.

The bottom line: even though a storm may be thousands of miles away and a week away from impact, we still have a responsibility to be ready.

 

CJ Sabo, MPH, EMT-B, HAP Manager, Emergency Management