AUSTIN (KXAN) — The most widely-respected seasonal hurricane forecast of the year was released today by Dr. Philip Klotzbach of Colorado State University, calling for another busier than normal Atlantic season with above-average tropical storm and hurricane activity.
|Forecast Parameters||CSU Forecast for 2021||Average for 1981-2010|
While predicting where storms will form and make landfall is difficult months in advance, CSU forecasters are expecting a higher than normal chance of a storm impacting Texas.
They diagnose Texas with a 75% chance of being impacted by a tropical storm this year (winds of 39-73 mph) compared to a typical season’s 58% chance. They also calculate a 49% of a hurricane hitting Texas (winds 74+ mph) compared to an average chance of 35%, and a 21% chance of a major hurricane (winds 111+ mph) impacting the state, compared to a 14% chance in a normal hurricane season.
United States impacts
The seasonal forecast calls for a high 69% chance of a major category 3+ hurricane impacting the United States coastline compared to a typical season’s 52% chance. The odds of a major hurricane impacting the Gulf Coast anywhere from Brownsville, Texas to the Florida Panhandle are 44% — higher than the average chance of 30%.
Why will it likely be an active hurricane season?
Predicting hurricane activity leans most heavily on ocean temperatures and the El Niño/La Niña cycle.
At this time, weak La Niña conditions are still in place with cooler than normal ocean waters in the Equatorial Pacific. This is important because the close tie of the ocean and the atmosphere mean that cooler waters there lead to less storm-killing wind shear over the Atlantic, and a more conducive environment for storms to develop.
Long-range La Niña forecast models now seem to be predicting a “double-dip” La Nina that KXAN first predicted in our March, 2021 special report. This would mean that the pattern which is weakening now could reintensify later this year, fostering Atlantic hurricane development.
Atlantic sea surface temperatures are largely warmer than normal at this time, and computer model forecasts expect a high likelihood of that continuing through the 2021 hurricane season.
Ocean temperatures are more likely to be warmer than normal these days due to manmade climate change.
Looking back at record-setting 2020 hurricane season
The 2020 Atlantic hurricane season shattered a handful of all-time records producing 30 named tropical storms, 11 U.S. storm landfalls, the latest category 5 storm on record and first Greek-named storm to reach category 5 strength, and 9 rapidly-intensifying storms. Hurricane Eta and Hurricane Iota’s wind speeds intensified by a mind-numbing 70 knots in 24 hours.
8 storms impacted the Gulf Coast, four of those hitting Louisiana directly including Hurricane Laura and Hurricane Delta which struck only 10 miles apart on the coastline.
Preliminary counts by the National Hurricane Center tally 46 direct deaths and 51 indirect deaths in 2020. Direct deaths include people killed by wind, ocean flooding and rainfall flooding, while indirect deaths include heart attacks, electrocution and carbon monoxide poisoning from improperly ventilated generators. CO poisoning has been responsible for a much larger portion of indirect fatalities in recent years.
Every U.S. county along the Atlantic coastline except for two were at some point under a tropical watch or warning during the 2020 season, including the Texas coast from Tropical Storm Beta and Hurricane Hanna.
Stay with the KXAN First Warning Weather team as Atlantic hurricane season officially begins June 1.