New hurricane forecast predicts active 2020 Atlantic season

Infrared satellite imagery of Hurricane Harvey near landfall.
Infrared satellite imagery of Hurricane Harvey near landfall.

HOUSTON – Dr. Phil Klotzbach, a renowned tropical expert from Colorado State University, issued his annual Atlantic tropical season forecast Thursday. Based on his research, he thinks weather patterns this summer will likely be favorable for a more active season than normal.

Klotzbach predicts 16 named storms, eight hurricanes and four major hurricanes in the Atlantic basin this season. That’s slightly higher than the 12 named storms, six hurricanes and three major hurricanes that are considered normal based on historical data.

Dr. Phil Klotzbach's April 2nd forecast for the 2020 Atlantic hurricane season.
Dr. Phil Klotzbach's April 2nd forecast for the 2020 Atlantic hurricane season.

Klotzbach considers several factors when generating his forecast for the season, including the following:

Statistical and Dynamical Forecast Models.

Statistical modeling techniques incorporate historical hurricane data to calculate the probability of future hurricane events. Dynamical modeling, on the other hand, uses rigorous mathematics to calculate a forecast based on measurements of real, current atmospheric variables like wind, pressure, and temperature.

Probability of La Niña vs. El Niño.

A La Niña pattern is indicated by colder-than-normal water in the equatorial Pacific Ocean off the coast of South America. When La Niña is present, upper-level winds over the Atlantic are typically light, which is favorable for hurricane formation.

Conversely, an El Niño pattern is marked by warmer-than-normal water in the equatorial Pacific. During El Niño periods, upper-level winds over the Atlantic are strong. They inhibit hurricane formation.

This year, Klotzbach thinks a La Niña pattern is more likely.


Atlantic Sea Surface Temperature.

Think of water temperature as a measure of energy. As the Atlantic water temperature increases, the amount of energy stored in that water increases. So, the higher the water temperature, the more energy is available to generate and sustain hurricanes. The rule of thumb is that the sea surface temperature has to be 80°F or higher for there to be enough energy to generate hurricanes.

This spring, the Atlantic Ocean is warmer than normal. If that trend continues, it points toward an active hurricane season.


Analogous Years

One way to predict how a hurricane season might unfold is to compare it to history. Study previous years that had analogous weather patterns to the current year and you might find that history will repeat itself. This year, Klotzbach identified 1960, 1966, 1980, 1996 and 2008 as analogous years to 2020.

You can see that there are a lot of considerations that inform Klotzbach’s annual forecast. Taken together, he believes that there is a good chance for us to see a busy season.

In addition to predicting overall activity, Klotzbach goes on to predict the probability of landfall in different parts of the United States. This year, he estimates a 69 percent chance for landfall somewhere along the entire coast of the U.S. In a normal year we would see a 52 percent chance. Breaking it down further, he predicts that the East Coast and Florida Peninsula will have a 45 percent chance for a hurricane landfall (31 percent is normal). The area from the Texas coast to the Florida Panhandle has a 44 percent probability (30 percent is normal).

Probability of landfall in the U.S.
Probability of landfall in the U.S.

Klotzbach will update his forecast on July 7 and again on August 6, incorporating new data into his calculations to improve its accuracy.

As with any forecast, this forecast is not perfect. There is no guarantee that it will verify. However, it does provide educated insight into what we might see. Most importantly, it gets our minds focused on the fact that hurricane season is right around the corner. And, even in the midst of the coronavirus crisis that has consumed our nation, we need to make time to get our hurricane plan in place. Now is as good a time as any!

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