Does El Nino impact Atlantic Ocean Hurricanes?

Hurricane Gonzalo, October 2014  Source: NASA

If you’re one of those people thinking this year’s hurricane season has been quiet, than you would be correct.  Although a tropical storm developed in May (Ana) – before the season officially began – it has been a relatively quiet season.  In fact, NOAA recently issued the August update to its seasonal hurricane forecast and concluded the 2015 hurricane season should remain quieter than average. 

That’s largely because of the developing El Nino event that is characterized by warmer sea surface temperatures in the central and eastern equatorial Pacific Ocean.  This situation affects global weather patterns and helps make conditions more favorable for tropical storm formation off the west coast of Mexico.  However, El Nino also tends to make conditions in the tropical Atlantic Ocean less favorable for tropical storms.

NOAA’s early August update for the 2015 Atlantic hurricane season predicts a total of 6 to 10 tropical storms, of which 1 to 4 will become hurricanes with up to one “major” hurricane – Category 3 or higher on the Saffir-Simpson Hurricane Intensity Scale.  So far this season, there have been only three short-lived tropical storms.  No hurricanes have developed anywhere in the Atlantic Ocean Basin (that includes the Caribbean Sea and Gulf of Mexico) since Gonzalo last October.

People tend to forget that a quieter than average hurricane season doesn’t necessarily mean that it can’t or won’t feature a high impact storm.  For example, the 1992 season was quieter than average (concurrent with a moderate El Nino event) and featured only 7 tropical storms, 4 hurricanes and 1 major hurricane.  However, many will remember that “major” storm as Hurricane Andrew.  In fact, Andrew was named as a tropical storm on this date 23 years ago and went on to become only the third Category 5 hurricane on record to make landfall in the United States.

Although the busiest part of the hurricane season is just getting underway (with September averaging the highest number of tropical storms and hurricanes), every expectation is for this season to finish up being the third consecutive quieter than average one.  Meteorologists at the National Hurricane Center will track any developments in the tropics while my colleagues and I on the WUSA9 weather team will continue to monitor any tropical storms that form should they track toward the U.S. East Coast.

Where has the Triple Digit Heat Gone?

Prado Museum, Madrid, Spain

Triple-digit heat is a rarity for the Mid-Atlantic Region.  That’s because triple-digit temperatures are most common in arid climates away from water.  However, summers in the Nation’s Capital often feature very humid weather.  When the air is more humid, it cannot heat up or cool down as quickly.  Washingtonians typically experience 100 degree heat only every few years.  That makes the 2010 – 2012 summers unusual since triple-digit heat occurred in the Nation’s Capital multiple times. 

 

The summer of 2012 was particularly memorable since there were eight days that were at least 100 degrees.  Meanwhile, this summer has been the warmest in the Nation’s Capital since 2012, with the highest number of 90 degree days since then (53 to 39 so far in 2015), but no triple-digit heat.

Although no record highs have been set in the Mid-Atlantic Region this summer, that’s not the case in Europe where multiple record highs have been set.  In Spain, Madrid’s hottest June temperature on record of 104 degrees occurred on June 30.  London’s hottest temperature on record of 98.1 degrees occurred on July 1.  Meanwhile, Warsaw, Poland had its hottest August temperature on record this past Saturday when it was 97.9 degrees.

It’s also important to note that the National Weather Service followed up on recent assertions by some area scientists and the media that temperature readings at National Airport appeared unusually high compared with nearby suburban areas.  Upon investigating, Jim Lee, the Meteorologist-in-Charge of the Sterling, VA, NWS office said: “It looked like it [the sensor] was reading 1.5-2 degrees too high,” at National Airport.  So technicians replaced it on Monday and it’s expected that will reduce falsely high temperature differences in the DC Metro Region.