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Weak El Nino? What could that mean for D.C. Winter - Comparing the past

October 17, 2014 - 03:15 PM
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Now that we have established that in the D.C. region, the summer of 2014 wasn’t quite as cool as we had perceived it to be, we can now move on to the winter of 2014-2015. Does a cool summer mean a harsh winter? I have been getting this question a lot, especially as we head into the end of October.

I decided to go back to ALL of the harsh winter’s Washington D.C. has recorded since 1899 and tried to find exactly what the summer preceding that harsh winter was exactly like and if we were experiencing a La Nina year, an El Nino year or a neutral year since that gives us an idea of our winter long range forecast. Again, these are all from Washington, D.C. National Weather Service forecast office (it had moved a couple times throughout this history but was always within the District of Columbia). 

1899: The Great Eastern Blizzard of ’99.
The Winter: This storm moved into the Washington D.C. region on Valentine’s Day, a Tuesday in 1899. Snow was reported as far south as Florida with around 21.0” of snow falling on the Washington D.C. and Baltimore area and up to 16.0” as far as New York. Pretty gusty winds that accompanied the Blizzard caused serious snow drifts that blocked transportation lines into Washington D.C causing a coal shortage. The Washington area had a snow depth of 34.0”. This was also the winter of The Great Arctic Outbreak in winch temperatures were so cold all across a good portion of the United States that the National Weather Service reports that ice flowed from the Mississippi River into the Gulf of Mexico.

The Summer of 1898:  With an average summer temperature of 75.0 degrees and an observed temperature of 76.0 degrees, the meteorological summer of 1898 (June – August) was 1.0 degrees WARMER than average.

January 28, 1922 “Knickerbocker Storm”:

The Winter: This storm was a crushing blow to the Washington D.C. area. A heavy snow of 28.0” was measured in Washington D.C. with higher amounts around the regions. This was the infamous “Knickerbocker Storm” where around 100 people were crushed to death as the roof at the Knickerbocker Theater on 18th and Columbia in NW Washington succumbed to heavy snow.

Summer of 1921: The summer preceding the “Knickerbocker Storm” was 0.83 degrees WARMER than average, but just by a very thin margin. The average temperature was 74.6 degrees for the summer and the summer of 1921.

April 1st, 1924 “Aprils Fools Day Storm”:

While this storm was mild in comparison with other storms of the past, this was the latest snowfall of the season of this amount. (This was considered a major snow storm because it accumulated more than 4.00”). Actually 5.00” of snow fell on the Washington area (a trace of snow fell on May 10th, 1906 but again, this was the most snow recorded this late in the season). Baltimore received 9.00” of snow with this storm.

The summer of 1923 was once again just a touch on the warmer side with the average temperature for the summer at 74.6 degrees and an observed temperature for the three summer months was 75.2 degrees. This means that D.C. was 0.63 degrees WARMER the summer before the April’s Fools Day Storm.

February 7th, 1936:

While this storm does not have a name, the Spring following this Winter helped set up for “The Great Spring Flood of March 1936” which was recorded as one of the worst floods for the Potomac River and Washington D.C. More than 14.0” of snow fall around Washington D.C. with more amounts through the Eastern Shore, Southern Maryland and south. All that snow helped lend to the massive flooding of the Potomac River through the spring.

Temperatures for the summer of 1935 were at 74.6 degrees for an average. The summer was very warm with temperatures topping out at 1.95 degrees ABOVE the normal temperature!

March 29th-30th 1942

This was a big storm that is actually still spoken about to this day! The “Palm Sunday Snowstorm” was a late bloomer, moving in at the end of March. However, it was a big snow producer dropping a foot of snow on Washington D.C. That was a minimal total compared to Baltimore, which received the greatest snow accumulated with one storm in 20 years! Baltimore recorded 22.0” of snow and Hagerstown measured 22.0” of snow as well in about 24 hours!

Chalk it up as another warm summer around Washington D.C. with temperatures 1.0 degrees WARMER than average. The average temperature for the summer of 1941 was 74.6 degrees with the observed temperature at 75.6 degrees.

January 30th-31st 1966

Strong El Nino Year. A pretty bad winter was upon the D.C. region during 1965-1966. With already snow on the ground, a blizzard came whisking through the region dropping one to two feet of snow through Virginia and Maryland. Washington D.C. recorded 14.0” of snow while Baltimore received just around a foot. There of course were some higher totals through Fredericksburg and Manassas.

The summer leading up to the fairly bad winter was almost near normal. The average temperature for the summer of 1965 was 76.3 with a recorded temperature of 76.0 degrees. That means the summer of 1965 was 0.3 degrees BELOW average, slightly just still below.

January of 1977 “The Bicentennial Winter”

Weak El Nino Year: This was a harsh one to say the least. This was one of the coldest winters recorded on the East Coast. The average temperature in Washington for January was 25.4 degrees which was the coldest since 1856 when the average temperature was 21.4 degrees (the normal temperature for January was 34.6 degrees)! The Carter Administration was getting settled into Washington and starting on January 4th, snow kept falling every few days. It was just a few inches here and a few inches there. Believe it or not, the Tidal Potomac (which is salt water) was frozen solid with the cold temperatures! People could actually skate across it to the Memorial Bridge! This winter was terrible for everybody – in fact, snow was even seen in Miami, Florida on January 19th. (Courtesy of NWS-Sterling)

Looking back at the summer of 1976, the average temperature was just slightly above normal for the meteorological summer, only 0.8 degrees warmer. The average temperature for those months was 76.8 degrees and the D.C. area measured a summer with an average temperatures of 77.6 degrees.

February 18th-19th 1979


Neutral Year: “The President’s Day Storm” was a one that a lot of people around the region remember as well considering it was thought to be the worst storm to hit the Washington, D.C. region in 57 years. Snow was recorded as falling 2”-3” per hour during the storm! One of the most interesting facts about this storm is that there was a protest on the National Mall with tractor trailers and other large farm machinery to protest for higher agricultural pricing. The protestors on the mall ended up using their equipment to help people dig out of the depths of snow that were around 2 feet!


With another bad winter upon the D.C. area in 1979, the summer of 1978 was a hot one. Temperatures were 2.1 degrees ABOVE normal! The average summer temperature for that summer was 78.7 degrees and the Washington D.C. area observed a warm average temperature of 78.9 degrees.

February 11th-12th 1983


Strong El Nino Year: Up to this point in history, the February storm of 1983 was the 2nd greatest snowfall on record for the Washington D.C. region as 24-hour snowfall records were set in some of the surrounding areas and D.C. received 17.0” of snow with this storm. There was more snow if you traveled outside the city, snowfall totals were up to 2 feet in some areas. Not only was the region dealing with large snowfall totals but gusty winds also caused large snow drifts around the Mid Atlantic.


The summer preceding the snowstorm that beat out the President’s Day Snowstorm was actually slightly cooler than average. The average temperature for the summer of 1982 was 76.8 degrees and D.C. observed a temperature of 76.2 degrees. That means D.C was 0.6 degrees BELOW normal for that summer.

November 11th, 1987 “The Veteran’s Day Storm”


Moderate transitioning into Strong El Nino Year:
Who can remember this storm? I actually do because my mom had to learn how to drive stick in a snowstorm to get me to an emergency dentist for a screaming 5 year old-oh memories. The snow came down fast a furious and right and took people by surprise considering these were the days before Doppler radar. By the time the snow moved through Fredericksburg, dropping heavy amounts, it was too late and meteorologists didn’t even really grasp what was happening until snow reached the forecast office in Camp Springs. Around a foot of snow fell across the region as motorists were still out and about. Stranded cars decorated area roadways.


This was actually a very warm summer in 1987 and an early massive snowstorm that followed. Temperatures in the summertime were 2.2 degrees ABOVE normal. The average temperature for that summer was 77.0 degrees and D.C. topped out at 79.2 degrees!

March 13th – 14th 1993 “The Superstorm of March ‘93”

Coming out of Moderate El Nino this was a Neutral Year: Yet another memory because I was pretty sure, growing up in Winchester, VA, I was never going back to school after this one (which was fine by me at that point in my life). This was a massive storm, with the lowest pressure ever recorded at the storm’s center, that affected the entire east coast. Not only did it cause huge storm surge through the Florida panhandle and several tornadoes (several deaths resulted in those weather events as well), it dropped more than a foot of snow across multiple states. Although this was an incredible storm, D.C. has seen worse. D.C. recorded 13.0” of snow with almost a foot right outside the city; in the suburbs and in extreme southwest VA some totals were around 40.0”. There were plenty of strong winds accompanying the storm as well as this was a true blizzard. Snow drifts were over 12 feet, the National Guard was called in and there were several deaths not only from hypothermia and collapsed roofs but more commonly from overexertion leading to heart attacks while shoveling snow.

I wouldn’t exactly call the summer of 1992 a warm summer as temperatures in the Washington D.C. area were 1.9 degrees BELOW average. The average temperature for that summer was 77.0 degrees and D.C. measured a temperature of only 75.1. June and August were particularly cooler.

The Winter of 1994

Neutral Year: Several ice storms pelleted the D.C. area early in 1994 and temperatures plummeted below zero several mornings. This is thought to be the iciest winter on record for the D.C. area. During January and February, there were multiple storms that not only dropped sleet but snow a freezing rain as well. One storm in particular on February 10th left a coating of ice that was 1.00” to 3.00” thick across the region! Due to the thick coating of ice, there were several power outages as falling trees and power lines due to heavy ice were to blame. There was a disaster declaration given in our area and several injuries as a direct result of the heavy ice coatings.

The summer of 1993 was a warm one with temperatures 1.3 degrees ABOVE average. The average temperature was 78.0 degrees with the D.C. area observed a warm temperature of 79.3 degrees.

January 7-13, 1996: The Blizzard of '96

Weak La Nina Year: Another one for the record books, another one in recent memory. If you were north and west of the District, you were dealing with almost 40.0” of snow in some areas while D.C. was climbing out of around 20.0” of snow. Just as the roads started to clear, an infamous “Alberta Clipper” came diving into our area out of the northwest bringing another shot of several inches of fresh snowfall. And then, just when we thought it was over, a third storm moved into the area piling on another 4.0” to 6.0” of snow in the District with more north and west of D.C. All in all, around 2 to 3 feet of snow accumulated after these series of storms.

Another warm summer preceded a nasty and snowy winter with temperatures in the summer of 1995 1.1 degrees above normal. The average temperature was 78.03 degrees and we measure a temperature of 79.13 degrees bringing us a summer that was 1.1 degrees ABOVE average.


February 15-17, 2003
Moderate El Nino Year: Moving into the 21st century, another strong storm was moving up the eastern seaboard in mid-February while temperatures were measuring in the teens. As this Nor’easter was developing, heavy snow began to fall into the overnight and early morning hours on February 16th. The snow continued through Presidents Day morning, February 17th with totals in D.C. topping out at 26.8” of accumulation.

Another very warm summer on tap for the region as temperatures were 2.3 degrees ABOVE normal for the meteorological summer! The average temperature for that summer was 77.03 degrees in D.C. while temperatures warmed up to 79.36 degrees!

Winter of 2009-2010
Moderate El Nino Year: Here we go. The winter that never quit and the first time I had to get on air and say “yeah, we are going to see 30.0” - 35.0” of snow in spots (with only 2 years under my belt as a Chief Meteorologist at my first station, I was almost in tears to know that I could completely bust this forecast and never work again if this prediction didn’t come to fruition, fortunate for me, it did – unfortunately for everybody else, it did as well). This was one of many weekend storms we saw that winter with snow rates at 2.00” per hour at times. That was the first storm that came through on December 18th and 19th. By January, we had our fair show of “little” storms –dropping over 5.00” in spots at times and then came a blizzard on February 5th and 6th. That storm dropped 17.8” in D.C. with over 3 feet of snow north and west of town. Then just when we thought we had enough, we got another blizzard on February 9th and 10th. DC received an additional 10.8” of snow with up to 2 more feet recorded in areas. That winter, DC saw 56.1” of snow fall. That is the number one winter for snowfall in the Washington D.C. area as long as records have been kept (since the late 1800s)!

The summer of 2009 was pretty much on average. Yes, temperatures were just slightly cooler but only by 0.2 degrees. The average temperature for the summer of 2009 was 77.0 and we reached 76.8 degrees with a pretty warm August on tap to help close the deficit from a cooler than average June and July. Therefore, we were 0.2 degrees BELOW average for the summer of 2009.

Winter of 2013/2014

Neutral Year: And yes, another winter that never ended! I couldn’t believe that we were seeing St. Patrick’s Day snow. It was the middle of March and we had been dealing with minor snowstorms since December! We had a least 9 snow events last winter around the region where several inches of snow were reported. Eventually, DCA totaled 32.0” of snow for the season. 32.0” of snow does not even fall into the top 5 snowiest winters for D.C.

The summer last year was just slightly warmer than our average summer. The average summer temperature for June to August is 77.7 degrees and DC warmed up to 78.3 degrees for all three months combined. That is 0.6 degrees ABOVE average.

El Nino vs La Nina vs Neutral

 

 

ZZZZZ

 

Wow. There is so much I can write on this subject. However, without turning into a very lengthy term paper with lots of graphics and images; let me just give you the short and skinny of it because these events strongly and often dictate the patterns of precip and temperatures globally. It is a very interesting meteorological phenomenon: the correlation between the sea surface temperatures and the atmosphere in the eastern Pacific. According to NASA’s definition of these events, “the development of El Niño events is linked to the trade winds. El Niño occurs when the trade winds are weaker than normal, and La Niña occurs when they are stronger than normal.”

El Niño: Unusually warm temperatures in the eastern Pacific when warm water builds up and migrates along the equator in the eastern Pacific. Of course, this warms the atmosphere creating thunder and rain storms.

 

ZZZZZ

 

La Nina: Unusually cool temperatures in the eastern Pacific when cool water builds and migrates along the equator. This event cools the atmosphere and less water evaporates creating fewer rainstorms in response to the cooler and drier dense air.

ZZZZZ

 

 

Neutral: This is the period (like we were in 2013-2014) when neither La Nina nor El Nino is present. This can be chalked up as a likely transition period to either a La Nina or El Nino event. Pretty much everything (ocean temps, tropical rainfall patterns and atmospheric winds) is right around average.

With that being said and according to the NWS, during El Nino years (and depending on the strength) “there appears to be some historical correlation between the strength of the El Nino and the warming in the Pacific Ocean and seasonable temperatures, precip and snowfall. Weak El Niño winters averaged below normal temperatures and precipitation, while strong El Niño episodes averaged above normal temperatures and precipitation. On average, the stronger the El Niño episode, the warmer and wetter the winters have been. These findings can partly be linked to a stronger than normal sub-tropical jet that typically occurs during moderate to strong El Niño winters, which would favor more active storm systems from the south that draw warm, moist air northward as opposed to the drier Alberta clippers from the northwest. Seasonal snowfall averaged above normal for weak, moderate and strong El Niño.” –credit www.erh.noaa.gov

 

 

ZZZZZ

As for La Nina years (in the winter’s that I analyzed, I only recorded one – which was a weak La Nina from 1995-1996 and approximately 20 winters were influenced by La Nina episodes since 1950) and according to the NWS “there appears to be some historical correlation between the strength of the La Niña episode and seasonal temperatures locally at Washington D.C. and Baltimore: the stronger the La Niña, the warmer the temperatures averaged. Winter precipitation averaged slightly drier than normal during all La Niña intensities. Seasonal snowfall during La Niña winters averaged below normal during moderate and strong episodes. However, while almost all of the La Niña episodes are linked to near or below normal snowfall at Washington D.C. and Baltimore, the weak La Niña episode during the 1995-96 winter was an outlier in the dataset with well above normal snowfall for the season. In this case, the above normal snowfall was weighted heavily by the 6–8 January 1996 blizzard, when 17.1 (22.5) inches of snow fell at Washington D.C. (Baltimore). –credit www.erh.noaa.gov

 

ZZZZZ

So what do we have in store for the end of 2013 through the spring of 2014 in terms of El Nino/La Nina?

The Climate Prediction Center has issued a statement that they expect (67% chance) of a WEAK El Nino to develop from October 2014 through December 2014 and continue through early 2015. Right now, observations in the Pacific are consistent with neutral conditions (same as last year) but there is a 67% chance of transitioning to most likely a weak El Nino event or a slight chance of a low-end moderate El Nino. Check our Alex Liggitt's blog for an in-depth look on the CPC's predition.

So there is the information and honestly we are just touching the surface as to what goes into a seasonal forecast: historic trends in both the winter and the summer, the Pacific Ocean temperature, wind movement, contrast and comparison. So if we happen to see a weak El Nino develop, maybe check back and see how that compares to the winter of 1977. Hopefully it WON’T be like that year.

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2014 hurricane season winding down with only five named storms

October 4, 2014 - 06:00 AM
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With less than two months to go, the 2014 Atlantic hurricane season has been lackluster at best. Earlier this year, NOAA predicted near-normal to below-normal tropical season. One factor could be the development of El Niño along with cooler Atlantic water temperatures. The original forecast was for eight to 13 named storms, three to six becoming hurricanes and one or two becoming major hurricanes.

2014 Named Storms

NOAA was not the only organization to forecast less tropical activity this year. The Tropical Meteorology Project headed by Dr. William Gray and Dr. Philip Klotzbach predicted a season with only nine named storms, three becoming hurricanes and only one major hurricane.

2014 Named Storm Tracks (NOAA)

The official count this season: four hurricanes, one tropical storm and one tropical depression.  Don't let the slow season, so far, mislead you.  Hurricane season goes through November 30th.  Stay with the Stormwatch weather team for the latest tropical updates.

 

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