In August, the National Oceanic and Atmospheric Administration (NOAA) predicted an above-normal hurricane season, with a 70% of chance of 14-21 named storms, of which 6-11 could become hurricanes, and 2-5 could become major hurricanes.
Hurricane season in the Atlantic Ocean runs from June to the end of November, with the most activity occurring in mid-August through mid-October. NOAA issues its predictions for the season in May each year. Predictions include the number of hurricanes, major hurricanes, and named storms[1] that will occur.
This year marks the fourth year in a row that NOAA predicted an above-normal hurricane season. A “normal” season is defined as seven hurricanes, with three of those hurricanes being Category 3 or higher. In 2020 the US experienced its highest rate of hurricane incidences, with thirty-one hurricanes throughout the season.
How does NOAA make Atlantic hurricane predictions?
The Pacific Ocean’s surface temperature affects wind patterns that lead to the development of Atlantic hurricanes. NOAA uses this data to predict Atlantic hurricane season trends.
During normal conditions, trade winds carry warm water from South America to Asia, with cold water rising from the depths, a process called upwelling. El Niño and La Niña disrupt these conditions. El Niño weakens trade winds, pushing warm water toward the Americas affecting weather patterns in the northern US and Canada. Conversely, La Niña strengthens trade winds, leading to drought in the southern US and more rain in the Pacific Northwest.
NOAA utilizes these patterns to predict and prepare for hurricane seasons, as they can affect their severity and frequency, demonstrating how global climate events impact local weather phenomena. This year's shift to El Nino lead NOAA to increase their predictions for the strength and number of Atlantic hurricanes.
NOAA also predicts hurricanes by determining if conditions are present in the Atlantic Ocean. These formative conditions include warmer sea temperatures in parts of the Atlantic Ocean and Caribbean Sea, thunderstorm activity, and low wind shear.
What counties have been hit the most by hurricanes in the past?
Sixteen states and have been hit by the eye of a hurricane since 1851, the year data collection started. The eye is the very center of a hurricane that is usually about 20 to 40 miles across. The eye itself has relatively low wind speeds but is surrounded by the “eyewall”. The eyewall is where hurricane winds are at their highest levels, often causing the most damage.
Monroe County in Florida, located at the southernmost tip of the state, has been hit by a hurricane eye 45 times since 1851, the most of anywhere in the country.
| County | State | Number of Hurricanes |
|---|---|---|
| Monroe | Florida | 45 |
| Carteret | North Carolina | 25 |
| Plaquemines Parish | Louisiana | 21 |
| Terrebonne Parish | Louisiana | 20 |
| Bay | Florida | 18 |
| Cameron Parish | Louisiana | 17 |
| Miami-Dade | Florida | 16 |
| Suffolk | New York | 16 |
| Galveston | Texas | 16 |
| Brunswick | North Carolina | 15 |
| Franklin County | Florida | 14 |
| Okaloosa | Florida | 14 |
| Lee | Florida | 13 |
| Charleston | South Carolina | 13 |
| Baldwin | Alabama | 12 |
Check out the USAFacts Climate Hub for monthly data on severe weather, precipitation, and temperature over time, and get the data directly in your inbox by signing up for our email newsletter.
[1] A named storm is a tropical cyclone with a maximum sustained surface wind speed of at least 39 miles per hour.
