Even though the National Oceanic and Atmospheric Administration (NOAA) predicted this year’s Atlantic Hurricane Season would be below-normal, the early May landfall of Tropical Storm Ana in South Carolina and Tropical Storm Bill near Houston, TX on June 16 hinted that NOAA might have gotten things wrong.
But as it turned out, there have been only 4 tropical storms (Ana, Bill, Claudette, and Erika) and only one hurricane (Danny) in the Atlantic this whole summer. Hurricane conditions have been so lousy that, back on August 6, 2015, NOAA released its revised forecast announcing it was 90% sure this year would be below-normal with even fewer storms:
- 6-10 named tropical storms
- 1-4 category 1 or 2 hurricanes
- 1 major hurricane
Where are the Hurricanes?
As with their earlier prediction, NOAA cites the emerging El Niño phenomenon as creating global weather patterns that disrupt the formation of hurricanes in the Atlantic ocean. And El Niño comes about due to warm water in the Pacific Ocean, their warm water affects wind circulation patterns world-wide (known as the “Walker Circulation”). Tropical storms and hurricanes develop in calm, warm waters.
For Atlantic hurricanes, the west coast of Africa is a perfect hurricane nursery. Storm systems swirl, build, and blow westward to the calm and sometimes warmer Caribbean. However, the wind circulation for an El Niño injects vertical wind shearing into the Caribbean, and this disrupts and dissipates storms. Not only does an El Niño inhibit hurricane formation, it also can blow out those that do form.
To learn more about El Niño at work, we can easily observe the effects from both Hurricane Danny and Tropical Storm Erika:
Hurricane Danny evolved from a tropical depression to tropical storm on August 18. It struggled to remain intact against a persistent mid-oceanic trough across the Caribbean region, strengthening to become a Category 1 Hurricane on August 20. By the next day, however, wind shear with drier air began wearing down the storm system and the hurricane eye disappeared. Danny weakened for the next 48 hours and on August 22, it was downgraded to a tropical storm. Wind shearing continued pulling the storm apart and by the end of August 24, Danny dissipated just west of the island of Guadalupe on the Leeward Islands.
Tropical Storm Erika began organizing a little further west of where Danny started and has followed a similar track. As of this writing (08/27/2015), NOAA reported that the storm had strengthened overnight, but it’s facing wind shear problems due to an upper level trough. Erika is poorly organized. If the storm survives the next 48 hours, it is expected to strengthen with the aid of a more favorable wind pattern as it passes over warmer waters.
This year’s El Niño is expected to be one of the strongest on record and exert its peak effects on temperature and precipitation during late fall or early winter this year.
Even though, this season’s hurricane activity is expected to be “below-normal,” there’s ALWAYS a chance a cyclone could form and barrel straight for the Lone Star State. So, it’s important to be prepared. Plus, there’s always the danger posed by plain old Texas summer storms.
Keep your family prepared by visiting the Light Lab’s Weather Prep Center for tips on how to prepare for the big storms, what to do when the lights go out, and more. You can also keep informed about storm-related emergencies and news by following us on Twitter and our Facebook page.