The 2019 Atlantic/Gulf hurricane season, which runs from June 1 through November 30, is expected to have average or slightly above average activity, with 12 to 14 named storms, including 5 to 7 hurricanes. Of these storms, 2 to 4 are expected to make landfall in the United States.
The best chance for a major hurricane strike will be in early September in Louisiana or eastern Texas, with other major threats for tropical storms or hurricanes in Florida in September and early October.
The Tropical Analogs map (see Figure 1) shows the track density of all tropical storms and hurricanes that have made landfall over the U.S. during the most appropriate historical analog years. Analog years are based on the solar cycle and activity, the current weather pattern, and the projected weather pattern into and through the coming hurricane season.
Note that the chosen analog years show that the greatest frequency of impacts during these analog years occurred over Florida, which corresponds well with our forecast of heightened activity there in September and early October.
Based upon this information, we see that the greatest potential for direct impacts from tropical storms and hurricanes will be in the western and northern Gulf of Mexico, all of Florida, and along the Carolinas coast. The analog years chosen suggest that if the current and projected weather patterns match up with those years, this could be an active year in Florida.
Factors in Hurricane Forecasts
In addition to solar cycles, major factors that play a role in hurricane and tropical storm formation and tracks include:
• The El Niño-Southern Oscillation (ENSO), which is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean. Although based in the Pacific Ocean, this plays a significant role in controlling weather patterns around the world and is one of the most important indicators of Atlantic Basin tropical storm activity. We expect a weak El Niño to continue through most or all of this hurricane season, which would cause somewhat greater wind shear, weakened storms, and less activity than average.
• Sea-surface temperatures in the Atlantic, Caribbean, and Gulf of Mexico. These are significant because warmer temperatures create more heat and moisture in the lowest levels of the atmosphere, which helps tropical storm development and intensification. Sea-surface temperatures are expected to be above normal, especially during the most active part of the season, which is August through October. Additionally, there should be regions of deep warm water, which would be favorable for rapid intensification and hurricane development.
• The Atlantic Multidecadal Oscillation (AMO), a measure of temperatures in this region. This should remain in its warm phase through the coming hurricane season. Warmer-than-normal water covers most of the Atlantic Basin at the current time, and climate models forecast this warm water to be in place for the entire season. So, even though the El Niño pattern might lower the number of storms, the warm water temperatures could still favor development of intense hurricanes.
• Vertical wind shear, which can inhibit the development of strong hurricanes by ripping them apart and preventing intensification. While high shear is forecast from the equator to about 20 degrees north latitude, low shear is expected from Florida to Louisiana and eastern Texas, which would coincide with our prediction of the most hurricane-prone areas.
Thus we see that although ENSO is not favorable for hurricane intensification, the other three factors above are, which is why we expect average or slightly above average activity this hurricane season, with Florida, Louisiana, and eastern Texas in greatest jeopardy.