Hurricane season has arrived, and communities are already dealing with the aftermath of Hurricane Beryl. Spanning from June to November, this period brings heightened vigilance and preparedness as meteorologists track potential threats and residents ensure their homes and families are safeguarded. Hurricanes, with their powerful winds and torrential rains, can cause widespread devastation, making it crucial for everyone in vulnerable areas to stay informed and ready. Whether it’s reviewing evacuation plans or stocking up on emergency supplies, preparation is key to weathering the turbulent months ahead.
“Hurricane season typically spans from approximately June 1 to November 30,” says Dr. Eleanor Casas, assistant professor of meteorology and expert in interactions between the tropical cyclone boundary layer and TC structure and intensity at Millersville University. “However, hurricanes are particularly active from approximately August 20 through mid-October. We have not yet reached the most active part of a typical Atlantic hurricane season.”
Casas says that this season is expected to be a highly active hurricane season, as Hurricane Beryl seems to indicate. This is due to extremely warm ocean temperatures and possible neutral ENSO or even La Nina conditions. These conditions mean that low “vertical wind shear” conditions are more likely in the Atlantic Basin, which allows hurricanes to more easily spin “upright” like a top. However, regardless of predicted hurricane season activity, it only takes one hurricane to be an active season for those impacted, such as those in Texas from Beryl. Coastal residents should always have emergency preparations and plans regardless of seasonal predictions.
Hurricanes are rotating weather systems with low pressure in the center but no strong temperature differences around them. To be officially classified as a Category 1 hurricane on the Saffir-Simpson scale, the sustained maximum wind speed must be at least 74 mph. However, Casas notes that wind damage is not the only hazard associated with hurricanes; a weak tropical storm or depression can still be devastating and life-threatening through various flooding hazards that are not currently factored into the Saffir-Simpson scale.
According to Casas, hurricanes typically affect coastal communities along the Gulf and Atlantic Coasts and in the Caribbean the most, especially by contributing to widespread flooding through heavy rain and storm surges. However, as we saw with Hurricane Beryl, inland states like in the Great Plains, Midwest, and broader East Coast can receive impacts of varying severity ranging from light drizzle to tornadic storms and hazardous flooding.
“States unlikely to be directly impacted by hurricanes are along the Pacific Coast and in the Mountain West,” says Casas. “Surprisingly, although Hawaii does also regularly get impacted by hurricanes, there is typically high “vertical wind shear” around Hawaii, which can help to “protect” the islands from hurricanes to a certain extent by “tilting” or “disrupting” the center of the circulation of approaching hurricanes and weakening them.”
So, what makes a hurricane different from a tornado? According to Casas, while both are typically classified as severe or extreme weather and spin rapidly, hurricanes and tornadoes are very different weather phenomena formed by very different processes. Tornadoes are a small but dangerous part of a severe thunderstorm, and you can see typically from one side of the tornado to the other when standing on the ground. In contrast, a hurricane is composed of many storm cells rotating about a center, and hurricanes can span the size of multiple states. Hurricanes can even spawn tornadoes within them when making landfall, more often on the side of the hurricane where the winds are blowing toward the shore or after landfall.
For more information about the remainder of hurricane season, you can check out the 2024 Atlantic Hurricane Season Outlook from Millersville University’s Weather Information Center Director, Kyle Elliott, here.