JACKSONVILLE, Fla. – Based on the Atlantic hurricane season so far and predictions for the next few months, Colorado State University (CSU) revised its long-term forecast, raising the number of storms and hurricanes it expects for the 2020 season.
CSU’s original prediction called for an above-average hurricane season, but the update released Wednesday raises the number of named storms from 20 to 24 and the number of those that become hurricanes from nine to 12. The prediction now calls for five instead of four of those hurricanes to reach Category 3 or higher strength.
Keep in mind that Isaias was our ninth named storm of the year and we haven’t reached the peak of the season.
“We have increased our forecast and now call for an extremely active 2020 Atlantic hurricane season,” CSU announced on its website.
CSU’s meteorologists explain that sea surface temperatures averages across the tropical Atlantic are much warmer than normal and vertical wind shear is well below average. Current cool neutral ENSO conditions may transition to weak La Niña conditions by later this summer. They anticipate an above-normal probability for major hurricanes making landfall along the continental U.S. coast and in the Caribbean.
Dr. Phillip Klotzbach, a research scientist in the Department of Atmospheric Science at CSU, explained the forecast in a series of tweets the different factors that contribute to the extremely active hurricane season:
One reason for increase in CSU Atlantic #hurricane season forecast is extremely warm tropical Atlantic sea surface temps. Currently 4th warmest on record (since 1982), trailing 2005, 2010 & 2017. Warmer water means more fuel for storms, also typically more atmospheric instability pic.twitter.com/X2S0HDlaBX— Philip Klotzbach (@philklotzbach) August 5, 2020
Another reason for extremely active Atlantic #hurricane seasonal forecast from CSU is due to very active West African monsoon. More robust easterly waves and more conducive upper-level winds for hurricanes in the tropical Atlantic are typically associated with active monsoon. pic.twitter.com/dQ1QtllAT3— Philip Klotzbach (@philklotzbach) August 5, 2020
Another reason for increased CSU seasonal #hurricane forecast is very weak vertical wind shear in July - 2nd lowest on record (since 1979), trailing only 2005. Weak vertical wind shear aids in hurricane development and intensification. pic.twitter.com/LhdDMRrSlS— Philip Klotzbach (@philklotzbach) August 5, 2020
Another reason for active CSU Atlantic #hurricane season forecast is odds of #ElNino this summer/fall are extremely low. Tropical eastern and central Pacific remains cooler than normal. Atmospheric circulation looking more #LaNina-like with suppressed convection near dateline. pic.twitter.com/YayVv9fn7D— Philip Klotzbach (@philklotzbach) August 5, 2020
CSU has chosen six analogs for its August seasonal #hurricane forecast: 1966, 1995, 2003, 2005, 2010 & 2017. All of these years had well above-average Atlantic hurricane activity & were generally characterized by cool neutral ENSO or #LaNina conditions and warm tropical Atlantic. pic.twitter.com/K2Yzy413xP— Philip Klotzbach (@philklotzbach) August 5, 2020
Multiple 2020 hurricane season outlooks have been released and they are trending toward an active year. They’re forecasting an above-average -- more than six -- hurricanes this season, which began June 1 and runs through the end of November.
Some are even calling for an "extremely active" season -- more than nine hurricanes.
There are over a dozen forecasts published. An official forecast from the National Oceanic and Atmospheric Administration gets updated Thursday, but a strong consensus already exists in the forecasts across the industry, indicating the U.S. in for an active season.
“In general, the consensus between seasonal hurricane forecasts this year is greater than it has been the past few years,” Klotzbach said.
Typically, these early forecasts vary a little bit more. This year the average forecast -- for all 13 groups that have submitted to Seasonal Hurricane Predictions -- is eight hurricanes and 17 named storms.
An average season sees six hurricanes and 12 named storms.