The Importance of Storm Track

Current Weather Map for the United States  (Source: NOAA)

Snow lovers in the DC Metro area know how important the storm track is in determining precipitation type and amount.  While sufficient cold air is necessary for snowfall, the storm track is important in providing moisture.  When there is only a marginal amount of cold air, the storm track assumes heightened importance since it can either help or hinder the amount of cold air.  That could make the difference between snow, snow mixed with freezing rain and sleet, or just rain.

Some of the largest snowstorms on record in the Mid-Atlantic region occurred with marginal temperatures.  The “Superstorm of March 1993” was one of the most significant on record in the eastern United States, with snow as far south as Florida and significant accumulations in Atlanta, Georgia and Birmingham, Alabama.  According to the National Weather Service, snow totals of more than 40” were common from West Virginia to New England.  However, there wasn’t enough cold air in place for pure snow to fall in Washington, D.C.  Instead, sleet fell at National Airport which reduced snowfall accumulations to 6.3”, far less than the 14.1” that fell at Dulles Airport and the 11.9” in Baltimore.

During “Snowmageddon” in February 2010, temperatures were just above freezing at the onset of the storm in the Nation’s Capital, with a few inches of heavy, wet snow to start.  The storm track made significant snowfall in the Nation’s Capital possible because it drew in just enough cold air to produce one of the largest snowfalls on record.  Washington, D.C. had its 4^th largest snowfall with 17.8”, while Dulles Airport had its largest snowfall on record with 32.0”.

Last month when the “Blizzard of 2016” was developing, a lot of Washingtonians were concerned about losing power again.  However, the circumstances were different as there had been an arctic air mass in place prior to the arrival of the blizzard which allowed the snowfall that occurred to be much drier than in 2010.  Consequently, there weren’t any significant power outages during this storm which tied for Washington, D.C.’s 4^th largest on record with 17.8”.  It was Baltimore’s largest snowstorm on record with 29.2” and was the second largest snowfall at Dulles with 29.3”. 

While coastal storms bring the Mid-Atlantic Region its largest snowfalls, significant snow can sometimes occur under different circumstances.  “Alberta Clippers” tend to be fast-moving, moisture starved systems that originate in the Canadian province of Alberta, but do on occasion bring accumulating snow along with a reinforcing shot of arctic air.  For example, a particularly vigorous Alberta Clipper brought 2.4” of snow to Washington, D.C. on January 6, 2015. 

Although today’s forecast includes winter weather for tonight and tomorrow, the setup is entirely different and much more unpredictable than last month's record-setting snowfall.  That’s because there is only a marginal amount of cold air in place, coupled with a higher degree of uncertainty in the exact storm track.  On a warmer note, Washington, D.C. tied its record high of 68 degrees for February 8 just one year ago today.

A Toast to Meteorologists

Meteorologists work tirelessly to educate and inform the public

“National Weatherman’s Day” or “National Weatherperson’s Day” is observed today in the United States.  It’s designed to recognize the hard work of meteorologists and weather observers (including volunteer weather watchers).  The weather community works diligently to provide the forecasts that people rely on in their day-to-day lives.  February 5 was chosen for “National Weatherman’s Day” because it’s the birthday of John Jeffries.  He was one of the first weather observers in the United States and began taking weather measurements in 1774.

The field of meteorology has a rich history with a variety of career paths, including weather forecasting, research and teaching.  Most positions that don’t involve research or teaching require only a Bachelor of Science degree.  The American Meteorological Society has information on colleges and universities that have both undergraduate and graduate programs in the atmospheric sciences.  Meteorology is one of the four earth sciences, along with geology, astronomy and oceanography.

Prior to the advent of weather radar during World War II and satellites shortly after, a key challenge was identifying areas of significant weather before it became visible to the naked eye.  Hurricanes, for example, were impossible to detect over the open ocean unless a ship happened to be in the vicinity.  Then remote sensing and computer models using math and physics began issuing forecasts (or “solutions”) that meteorologists use.

During the 1990s, access to the “world wide web” became widely accessible with people discovering email and the Internet.  Also, the development of smart phone technology and home high speed internet access has greatly increased the amount of weather information available to the general public.  However, without any method of quality control on the Internet, it’s difficult to discern if what you’re reading is from a reputable source.  Weather forecasting has an inherent degree of uncertainty and unless your information comes from a reliable source, there’s no way to ensure its accuracy.

Broadcast meteorologists have a key role in effectively communicating science information to a non-scientific audience.  The only access most people have to a scientist today is watching their favorite meteorologist during a local newscast.  The explosion of social media also facilitates public interaction between meteorologists and the viewing audience and gives the public a forum to ask questions and gain a better understanding of various weather terms.  Being a meteorologist is hard work and it’s a good idea to pay your favorite meteorologist tribute today for “National Weatherman’s Day.”

What Can You Expect In February?

NOAA's Temperature Outlook for February

Although Groundhog Day is a key part of weather folklore (and was made into a classic 1990s comedy starring Bill Murray), there are more accurate ways of predicting the weather.  The most famous groundhog, “Punxsutawney Phil,” and his predecessors have been predicting the weather for over 100 years!  Since 1887, he has seen his shadow 102 times, meaning “six more weeks of winter” were in store.  Although Phil’s “forecasts” aren’t known for their accuracy, the accuracy of weather forecasts made by humans have improve dramatically.

In Washington, D.C., February 1 has an average high and low temperature of 44/29, while February 29 averages 51 and 34 degrees respectively.  The warmest February temperature on record was 84 degrees on February 25, 1930.  February’s coldest temperature was -15 degrees on February 15, 1899.  Both temperatures predated National Airport which opened in 1941.  Since then, the warmest and coldest February temperatures observed at National Airport were 82 degrees on February 28, 1948 and 5 degrees which occurred twice – most recently on February 20, 2015.

According to the National Weather Service, February is the snowiest month of the year in the Nation’s Capital and averages 5.7” – narrowly ahead of January.  Seven of Washington, D.C.’s 10 largest snowstorms have occurred in February.  The second largest snowstorm on record occurred from February 12-14, 1899 when 20.0”.  Meanwhile, the largest snowstorm to occur at National Airport (and Washington, D.C.’s third largest overall) was on February 18-19, 1979, when 18.7” of snow fell.  Fortunately, for those tired of winter weather, there are no major winter storms are on the horizon in the Nation’s Capital.

This month has gotten off to a significantly warmer than average start in the Mid-Atlantic Region.  That’s helped the snowpack from the “Blizzard of 2016” melt rapidly.  Significantly warmer than average temperatures are expected tomorrow as temperatures are poised to reach the low 60s.  On the other hand, a significant winter storm is bringing the central United States heavy snow – and blizzard conditions in spots.  The same system will bring appreciable rainfall to the DC Metro Region tomorrow.  More seasonal temperatures will return Thursday. 

NOAA’s Climate Prediction Center’s outlook for February is for a slight chance of greater than average temperatures for northern portions of the DC Metro Region – closer to the Mason-Dixon Line.  That should be welcome news for many since the last three Februarys have been colder than average.  Just this morning, “Punxsutawney Phil” saw no shadow meaning people can expect an early spring.  However, the last time he called for an early spring in 2013, March saw above average snowfall in the Nation’s Capital.  So people can accept Phil’s forecast for an early spring for its sentimental value – but not necessarily it’s accuracy.