The 2010 Hurricane Season is in the books and while it was an active season, the U.S. was spared direct hits from major storms. Two things stand out for me this year as I look back on the season. First, the number of storms that formed off the West African coast but which curved away from the U.S. Second was how many indirect impacts we had even though there weren't any major landfalls. Third, the unexpected Deep Water horizon spill added even more uncertainty to the tropical threat which by its nature is already a tricky forecast.
An active season was expected due to the end of the El Niño pattern that limited the 2009 season. The switch of cooler equatorial Pacific water relaxes the jet stream winds over the Atlantic ocean. Less wind aloft is a key factor to storm development. Additionally, the ocean temperatures in the Atlantic were at an all-time high.
The first storm of the season actually had its origins off the West Coast of Africa. This concerned me since we don't typically see this kind of activity until late July when the so-called Cape Verde season kicks into gear. While the first wave fizzled when it got to the Caribbean, it regenerated in late June, eventually becoming the first hurricane, Alex. When Alex meandered into the Gulf, it became only the 13th June Gulf hurricane on record. I knew it was going to be a long summer tracking storms. Even though Alex came inland well south of Brownsville, it combined with a stalled front to give us soaking, flooding rains the first two days of July.
Before the season began, we spent a lot of time speculating on what would happen if a hurricane struck near the oil spill. Well, we found out when Bonnie formed. Early forecast projections had Bonnie becoming a tropical storm and moving right over the DWH site. Fortunately, that scenario didn't come to pass as Bonnie weakened considerably after swiping south Florida. In fact, there is some research that shows that the remnants of Bonnie helped re-mediate the oil.
As we entered into the Cape Verde season, a parade of storms marched across the Atlantic, pushed that way by high pressure parked over the ocean. While that is normally a set-up for sending storms to the East Coast or even the Gulf, we were spared due to favorable jet stream winds which deflected approaching storms. The only one that came close was Earl, which swiped the outer banks of North Carolina.
Surprising Labor Day storm Hermine mimicked Alex's path, but didn't deliver the same results here in Houston. It did, however, bring flooding rains to northern Mexico, the Texas Hill country and several tornadoes to North Texas. As the season wound down, there were quite a few threatening Caribbean storms. However, by that time, we were starting to see cold fronts which kept these storms from entering the Gulf and becoming a U.S. threat. That meant the storms were free to bring destruction to places like Jamaica, Haiti and St. Lucia.
Next year, La Niña is still expected to be going on which could mean another active season. Let's hope the impact here remains the same.