Weather Quiz

 

Hurricane Wilma, 2005  (Source: NOAA)

What was the strongest Atlantic hurricane on record during the month of October ?

  
A.  Opal (1995)


B.  Mitch (1998)


C.  Wilma (2005)


D.  Sandy (2012)

Beware Late Season Hurricanes

 

 

While not as active as September, the month of October can still be quite active in the tropical Atlantic.  However, the frequency and intensity of tropical storms and hurricanes often decreases as the month wears on.  That’s not to say there haven’t been intense and high impact hurricanes in October and November. 

Just yesterday, Hurricane Epsilon became a major Category 3 hurricane with sustained winds of 115 mph while southeast of Bermuda.  That made it the second major hurricane to develop since October 1, along with Hurricane Delta.  2020 is the first Atlantic season since 2005 to see two major October hurricanes.  Fortunately, Epsilon is weakening and will not have a direct impact on the United States.  That’s unlike some other late season hurricanes that were both intense and costly.

Sandy (2012) – The strongest hurricane of the 2012 season, Sandy reached Category 3 intensity with sustained winds of 115 mph.  It tracked north after its landfall in Cuba on October 25.  Eventually, it made landfall as a weaker storm in New Jersey, causing extensive coastal flooding with significant impacts that reached well inland.  Sandy also set a number of rainfall and low pressure records. 

Shortly before its landfall in New Jersey, Sandy was no longer a tropical system lost its tropical characteristics over cooler ocean waters and was considered a non-tropical or “post-tropical” storm.  Consequently, all the hurricane watches and warnings were discontinued.  That led to a lot of confusion since many people thought the storm was no longer dangerous.  As a result of this controversy, it was determined that future hurricane watches and warnings should remain in effect even after a given storm becomes a non-tropical system. 

Despite not officially being a tropical storm or hurricane at its time of landfall in the United States, the name “Sandy” was retired since it was both damaging and deadly.  Sandy remains among the costliest natural disasters in U.S. history.

Wilma (2005) – Before impacting the United States, Wilma was the strongest Atlantic hurricane on record with a minimum central air pressure of 882 millibars (mb), compared to standard sea level air pressure of approximately 1013 mb.  Its sustained winds also reached 185 mph, and that made it the fourth Category 5 hurricane of the epic 2005 season.  Fortunately, Wilma weakened significantly before it reached southwest Florida on October 24 as a Category 3 storm.  Wilma was also noteworthy for being the last hurricane to make landfall anywhere in Florida until Hermine in 2016.

Kate (1985) – Kate reached peak intensity in the Gulf of Mexico on November 20 with sustained winds of 120 mph and a minimum central air pressure of 953 mb.  Kate weakened slightly to a Category 2 storm before making landfall in the Florida Panhandle on November 21.  It was the latest landfalling hurricane on record in the contiguous United States.  Kate was also the fourth hurricane to impact the U.S. Gulf Coast during the 1985 season. 

Watch Out for Winter Weather

 

NOAA’s winter weather outlook for the upcoming 2020-2021 season expects warmer and drier conditions along the southern tier of the United States along with cooler and wetter conditions in northern areas.  A large consideration in its forecast is the episode of La Nina that’s developed.  La Nina is characterized by cooler than average sea surface temperatures in the tropical east Pacific Ocean – off the west coast of Ecuador.  That often has global repercussions, much like El Nino, though in opposite ways.  For example, El Nino conditions tend to create unfavorable conditions for development in the tropical Atlantic, while the current La Nina conditions have helped enhance the active 2020 Atlantic hurricane season.

La Nina winters in the DC Metro Area are often warmer than average with near average precipitation.  However, that can fluctuate depending on the intensity of the La Nina with weaker La Nina’s having less of an influence.  Washingtonians usually get below average snowfall during La Nina winters.  While the presence of El Nino or La Nina play significant roles in seasonal forecasts for winter, there are other factors to consider such as the status of the North Atlantic Oscillation (NAO).

Over the last two decades there have been some key winter weather trends in the Nation’s Capital.  For example, 14 of the last 20 winters have had below average snowfall, but four of DC’s 10 largest snowstorms have occurred in that time.  They include President’s Day 2003, December 2019, “Snowmageddon” in February 2010, and the epic January 2016 winter storm.  While DC averages 15.4” of snow annually, the perception of a winter can vary widely depending on whether that snow occurs during one large winter storm or with a series of smaller storms.

Thirteen of the last 20 winters have also been warmer than average in the DC Metro Area, including the last five winters.  However, a warmer than average winter doesn’t necessarily mean it will have below average snowfall.  A good example of that was the 2015-2016 winter that featured DC’s warmest December on record.  DC residents didn’t see the first measurable snowfall that winter until mid-January, shortly before its fourth largest winter storm on record – the epic “Blizzard of 2016.”  However, if you subtract the 17.8” that occurred at National Airport during that storm, DC only saw a combined 4.4” of snow the rest of the winter.

Washingtonians haven’t had more than three consecutive snowier than average winters (2013 – 2014 through 2015 – 2016) or more than three consecutive colder than average winters (2008 - 2009 through 2010 – 2011) over the last 20 years.  Last winter was largely ENSO-neutral (meaning an absence La Nina or El Nino) and finished as DC’s third least snowy winter on record with a seasonal total of only 0.6”.  Based on NOAA’s outlook, residents of the DC Metro Area can expect warmer than average temperatures and near average precipitation.