The dire hurricane predictions for an active 2013 hurricane season overshot the actual number of storms that occurred: thirteen named storms and only two hurricanes. In spite of warm waters off the west coast of Africa that make a nursery for powerful cyclones, most tropical systems dissipated before organizing into storms. This was due to unexpectedly high wind shear, as too much warm, dry air rushing off the Sahara created wind shears between 30 and 50 kts that tore apart the systems. This year, the emergence of an El Niño in the late summer/early fall will combine with both wind shear and cold water to keep the number of hurricanes “below normal.” Four major hurricanes prediction centers - The National Oceanic and Atmospheric Administration (NOAA), Colorado State University (CSU), Tropical Storm Risk (TSR) of University College London, and WSI - all predict a quiet hurricane season. Cold Water: Although the Polar Vortex would have you believe otherwise, the northern hemisphere is still experiencing a warm or “positive phase” from the North Atlantic Oscillaton (NAO). This produces stronger trade winds blowing off the Sahara that appear to be mixing and upwelling colder water from below to the surface. Some make the case that a weakening of the Atlantic Ocean Thermohaline Circulation (THC) led to additional cooling of Sea Surface Temperatures (SST) off west Africa in 2013. Presently, SST are below normal in the eastern tropical Atlantic, and this is expected to continue through to October. Without the heat energy stored in the top millimeter of ocean water, storms have a harder time forming.
El Niño Emerges: While there may be cool SST in the Atlantic, warmer temperatures in the equatorial Pacific are expected to create an El Niño phenomena beginning in late summer/early fall. El Niño events change weather and wind patterns around the globe by warming the air. One typical effect is increased wind shears in the tropical North Atlantic. Wind shearing reduces the chances for hurricane storm systems to form by spreading the storm’s heat over a larger area. El Niños also bring wetter, cooler weather to the southwestern US as well as milder winter temperatures to the Great Plains and Great Lakes regions. What isn’t predictable, however, is how strong the El Niño will be when it finally takes effect.
It’s Still Hurricane Season: Even if there is a lower than average expectation for hurricanes this year, it only takes one to cause a tragedy. Remember that hurricanes are not merely limited to the coast and that they can have a devasting reach inland as well. Make sure you and your family are prepared and have a plan. Be sure to check out NOAA’s National Hurricane Preparedness Week as well as these other helpful resources.
- Hurricane 101 – Preparing for the Storm
- Preparing for Hurricane Season
- Your Partner in Hurricane Preparation
- Some Not-So-Common Hurricane Preparedness Tips
- Weathering the Storm with Children
Plus check out the great information and storm updates at the Hurricane Prep Center You can also follow Direct Energy on Twitter for up to date information on emergencies in your area to help you weather any storm. Hurricane Brett image courtesy of wikipedia.org