Summer Outlook: Possible El Nino?

Image from SFSU

         After finally getting through a very stubborn winter, we now look forward to the warmer and drier summer season. Currently on every atmospheric scientists and meteorologists’ radar is the impending El Nino event–one of our planet’s most prevalent weather phenomena. El Nino is an intricate weather pattern that results from variations, or sometimes called oscillations, in ocean surface temperatures along the equatorial Pacific Ocean. Scientists declare an El Nino event when the Pacific Ocean water surface temperature, off the coast of Peru and Ecuador, becomes higher than 0.5 degree for three consecutive months. This warmer water cycle stretches 5,000 miles from South America, moving westward towards Australia and Indonesia. As this belt of water sweeps across the Pacific Ocean, trade winds weaken and even reverse course, creating a low-pressure system over areas, such as Peru and Ecuador, and a high-pressure system over Australia and Indonesia. A mild El Nino event is present when the ocean surface is warmed by 1 to 2 degrees Celsius, and stronger El Nino events occur when the water is warmer by 3 to 4 degrees Celsius. An El Nino event can last as long as several months up to an entire year.  Currently, temperatures in the eastern and central Pacific Ocean are the warmest on record for March since 1979. Australian meteorologists currently report water temperatures up to 7 degrees above the average. Another impending sign of an extreme weather event is the reversal of the Pacific trade winds. Therefore, this years’ El Nino event could compete as one of the most intensive on record. These El Nino events normally appear in the late winter season, but since this event currently appears to be very strong, scientists are expecting El Nino to make an earlier appearance, possibly this summer. 

       El Nino brings considerable global weather consequences. For the U.S. El Nino brings more storms to the California coast and wetter weather conditions in the southern states. The Pacific Northwest experiences warmer conditions, and a decrease in the threat from hurricanes on the Atlantic coast and Gulf of Mexico. We can also expect more storms to adversely impact the Californian coast. The west coast storms will finally bring rain to drought-ridden California. Also, due to a recent oil spill in the Gulf of Mexico, a quieter hurricane season is much needed so the spilled oil stays contained in a localized area and not wash up onto a wide span of coastline. We can also presume the continuation of a severe drought in Indonesia and India, more bush fires in Australia, drier conditions in Central America, and warmer global temperatures due to the heat released into the atmosphere from the tropical Pacific Ocean. So while North America receives wetter weather, Asia and Oceania receive drier weather.  The stronger the magnitude of an El Nino, the more drastic the consequences will be for the planet. 

Currently, the director of NOAA’s Climate Prediction Center reports that there is a greater than 50% chance of El Nino developing as early as summer and a 75% likelihood of it developing in fall. An El Nino watch has been issued to warn of the potential severe conditions that can occur around the world. Although spring El Nino predictions have proven to be incorrect in the past, all signs point that this El Nino event may be one of record proportions!

A question researchers are going to have to explore in years to come, is if climate change is increasing the frequency of El Nino events.

To extend your knowledge about El Nino, check out NOAA’s link.

Mason Day 2014 Forecast

Mason Day // Lot K // 2pm-8pm
Ludacris Concert // Patriot Center // 8 pm

Synopsis

A cold front will be sweeping through the area Friday afternoon bringing rain and gusty winds along. The day will start out partly cloudy but expect fully covered skies by 3 pm. Best chance for rain to start is just after 2 pm. Rain will go on until about 7:30 pm. There's a slight chance of a late afternoon thunderstorm. Temperatures will get no warmer than 68 degrees by 4 pm. Wind gusts will be at their worst between 2 and 5 pm. 

Hourly Forecast

2 pm - Rain beginning to fall // Winds SE 12 mph // 68 degrees

3 pm - Rain // Winds SE 13 mph with gusts 25 mph // 68 degrees 

4 pm - Rain // Winds SE 15 mph with gusts 25 mph // 68 degrees

5 pm - Rain // Winds SE 15 mph with gusts 25 mph // 65 degrees

6 pm - Rain // Winds SE 15 mph with gusts 25 mph // 63 degrees

7 pm - Rain // Winds SE 13 mph // 61 degrees

8 pm - Light rain // Winds SE 10 mph // 60 degrees

9 pm - Rain ending // Winds S 9 mph // 59 degrees

10 pm - Clouds breaking up // Winds SW 8 mph // 57 degrees

Winter Synopsis 2013-2014

This winter was cold. That is unquestionable. From a records standpoint this winter stands as one of the coldest in the past 50 years. For Fairfax and the rest of the DMV it was also one of the snowiest, with snow totals well above average. 

Winter snowfall totals for major cities (Accuweather.com)

That being said, with spring officially here, it is time to look back at the winter that was.

Pre-Winter-Temperatures started off relatively average for the most part. The main cooling took place around the time of Thanksgiving break and into December. The first snowstorm, Winter Storm Dion was a relatively weak storm which brought a mix of freezing rain, sleet and snow and of course our first batch of class cancelations. This was of course the first of many snowstorms during winter.

Early Winter: December 21^st-January 20^th- This Winter actually started on a mild note, with the first day of winter actually setting record highs across the region for the first couple of days. This confused many students and baffled even the likes of expert meteorologists. This quickly shifted though as the cold frigid air entered our region early January dropping temperatures into the single digits and dropping our first snow of winter. The lowest temperature of 2.8 degrees recorded on January 7^th was the climax of this cold spell.

Well below average for much of the month of January (Washington Post)

Mid Winter: January 21^st –February 20^th-The cold below average air started to take hold of the region. The bitter cold due to the arctic front set records and created situations with dangerously cold wind chills. On January 23^rd, a low of -2.7 degrees F was the lowest recorded temperature in the area in over 100 years. The cold stretch from the 22^nd-29^th produced lows in the single digits or lower for 8 straight nights. Temperatures were more seasonable into February. Our first major snow event happens with Winter Storm Pax which brought upwards of 6-10 inches for the entire region and a second round of school closings.

Runners enjoy serenity of empty streets during Winter Storm Pax

Satellite image of Winter Storm Pax

Late Winter: Febuary 21^st-March 20^th-Though this period started with some needed relief and even some days of above average temperatures; this quickly changed, with below 0 temperatures returning in early March. This followed quickly by Winter Storm Titan, a strong storm that brought an array of rain, freezing rain, sleet and eventually snow. Finally, winter wrapped up with an unexpected twist with almost a foot of snow on St. Patrick’s Day, breaking previous records for the day. This of course was not the end of the winter temperatures or snow.

Snow totals for the late and unexpected St. Patrick's Day snowstorm (NOAA)

Post-Winter: March 21^st-April 10^th- Just because spring has started, does not mean temperatures will rise on command. Especially with a cold air sustaining itself across much of the nation’s heartland, it has taken a bit for temperatures to rise. Finally though, it looks as if spring is here to truly stay.

Here are some questions about this winter I want to help answer:

Why was this winter so long and cold?!

Normal Daily Average and Actual Average trend lines (Washington Post)

This is the question that most people had as there was little doubt that this winter was one of the roughest when it came to the sure amount of frigid days and days with frozen precipitation present. It started out with a welcoming presence but soon almost the entirety of students became weary of the cold and yearned for warmer days of spring.

The answer lies surprisingly enough with the global climate change that has transfixed the entire atmospheric science and meteorology fields. Specifically the warming ice sheets of the Arctic played a pivotal role with the overall dip of cold air across the region.

Think of the North America not by region, but by large air masses. These air masses interact with one another all of the time, and produce the weather we all know. These air masses range in temperature (Tropical-Warm, Polar-Cold, Arctic-Frigid) and by location (Maritime-Ocean, Continental-Inland). Why this is important is that with the warming of the Arctic, these air masses will play a large role in huge temperature shifts. During the winter months, the tropical air mass shrinks and is confined to farthest Southeastern regions of the country while the polar and arctic air masses move southward. This winter, the Polar and Arctic air masses moved farther south than normal, which caused temperatures to free-fall across almost the entirety of the nation.

The Cold Air Mass moves south and eastward from its source region in central Canada

How this occurs is a fairly complicated process physically. Conceptually though, it is fairly easy to understand. The Arctic is warming at a fairly high rate. This is due to the fact that greenhouse emissions are being released into the atmosphere. What happens after they are released into the atmosphere is not a mystery either. The greenhouse gas for the most part does not stay in one location. Instead of staying dormant, it travels through the various canals and streams in the ocean sinks and upper-atmosphere upwards towards the poles as part of the heat transfer process; the basic process that keeps the equator from getting too hot, and poles too cold. A vast majority though stays within the Arctic, and through a positive feedback process, has melted a vast majority of the ice sheets and warmed the average temperature dramatically.

What does that mean for us?

-More than you would quite think. The jet stream is the upper-level air-flow at the top of the troposphere. It is caused by the planets rotation and temperature and pressure differentials between the arctic, polar and tropical regions and plays a large part with weather. A dip in the jet stream across our region could mean drastically colder temperatures and a ridge in the jet stream could mean tropical, humid air. With the warming Arctic, the jet stream has weakened due to the lack of temperature differential and corresponding pressure differentials of the upper atmosphere. This weakening has caused it to ‘meander’ which means larger dips and ridges. This along with the process of “blocking highs” which helps sustain a dip in the jet stream for long periods of time created a perfect storm for frigid conditions for several weeks during the heart of winter. The overall weather pattern also was affected during this time, creating almost a conveyor belt system of storm development bringing winter storm after storm across the middle of the county and into our region.

Jet Stream pattern for much of the winter. Notice the large dip towards the middle of the country, and the East South-Easterly winds bringing abundant moisture across the Midwest and Mid-Atlantic regions. (climatestate.com)

Were there other reasons other than the warming Arctic?

El Nino might have also played an important role as well in keeping this winter cold and wet. El Nino is a process of warming the waters across the Eastern Pacific ocean and the coinciding atmosphere to produce weakened trade winds and lower atmospheric pressure of the region. This process alone has momentous affects on the regional climate of North America. During an El Nino year, it is said that the winters of the Southeastern United States are cooler and wetter than normal years, while the Southwest is warmer and drier than normal. This March was the coldest and snowiest on record.

This shows the conditions present during an El Nino winter such as this year (NOAA)

This winter was actually very warm on average for this very reason in Alaska, which saw a very large ridge over a majority of the country for a large part of the winter. Weather is a all-encompassing concept, one thing directly affects another.

Will this mean that we will have a warm/hot spring and summer?

-To the best of my knowledge, I think it will be a relatively average this spring and summer with of course the normal amount of variations and anomalies. Even with the impacts of the possible El Nino this year, the climate forecast for this spring seems to point to average to slightly below average temperatures through the spring months.

The summer on the other hand is a little more hazy, as it is farther out on the time scale. 

There is an expected to be a large delay on severe weather events for the area this spring and early summer due to the lingering effects of the harsh winter. 

Severe Weather Climate forecast for this Spring/Summer 2014

Will more winters be like this?

-Again a hard question to answer, and one where a simple answer of yes or no might not be the best of responses. With the looming climate change, we can definitely expect a new set of rules for seasonal patterns. To keep it simple, yes there will be more like this, but in the immediate future the likelihood is highly doubtful for a winter in the next couple of years to be this harsh.

We at Forecast GMU enjoyed this winter as it brought us ample opportunities to give you sufficient detailed forecasts and vital information on the incoming winter storms and systems that directly impacted our area.  We always enjoy your feedback as we look forward to warmer temperatures and the end of an academic school year.

What are some of your questions about this winter? What were your favorite memories? 

Share them in the comments below or message Katie, Nick, or me with your questions.

-James 

New Atmospheric Science Major at George Mason University!

As of this Spring, there is an approved course list for an Atmospheric Science B.S at George Mason University. This is a great step for the growing Atmospheric Oceanic and Earth Science (AOES) department in their goal to help improve the visibility.

Before this major was announced, students like myself had to major in Earth Science and have an Atmospheric Science concentration. The course load compared to the new major is relatively similar, with some slight changes, noted below.

The Atmospheric Science department is divided into concentrations as well: a meteorology concentration and a computational science concentration.

Meteorology Concentration-This concentration focuses more on the pure scientific aspect of the study. Starting out with the very basics of atmospheric composition, it goes through the various dynamical steps without diving too deep into the computation and mathematical aspects.

Computational Science Concentration-This major is purely based on how forecasting is done in the field today. With required classes such as intro to programming and scientific programming, it introduces and teaches concepts that can directly be applied to graduate and eventual field work in computer model based forecasting.

This department is still young, and is still in the budding stage from within the College of Science. With the help of many different distinguished professors, this Major could be the one of choice for many new future meteorologists.

Changes from the old Earth Science Concentration in Atmospheric Science:

1. No more Physics 262/Math 214 as an overall requirement (it is needed for computational science)
2. Added required classes for the core such as Climate 411-Atmospheric Dynamics, Climate 429-Atmospheric Thermodynamics, and Physics 475-Atmospheric Physics
3.  Just Chemistry 211 required not 212
4.   For the meteorology option: new required class: GGS 312-Physical Climatology
5. For the computational science option: New classes such as CDS 251-Introduction to Scientific Programming, Climate 440-Climate Dynamics or Climate 470-Numerical Weather Prediction

Overall though amidst these changes, the major is fairly similar to the concentration. It varies only in the new class choices and the elimination of some required classes.

The major is still pending approval, but should be available by this fall. Click here for more info. 

Interested? Contact your advisor to start right away!

Washington Mudslide: What Happened?

            Residents of the Oso, Washington area were always aware of the possibility of a mudslide, but they could never have imagined the devastation that it would ultimately cause. The Washington mudslide is one of the largest and most destructive mudslides the U.S. has seen in a long time. It has been determined that extreme weather, in the form of heavy, sustained rain, was an essential factor leading up to the event.  The mudslide was 4,400 ft. long, 4,400 ft. wide and up to 40 feet deep. To put that into perspective that's as high as four stories. 

One of the many questions people are asking is what’s the difference between a mudslide and a landslide? A mudslide occurs when the rapid movement of a large mass of mud (formed from loose earth heavy with rain) moves destructively downhill. A landslide is the downward movement of the ground, such as rockfalls.

          Initial news coverage reported up to 120 people missing, but as of now there are 30 confirmed dead and 13 people are still missing.

Setting the Scene

The Soil: Twenty thousand years ago glaciers covered the impacted area.  As the glaciers gradually retreated they left behind very lose soil, sand and glacial rock. This loose layer of soil sits on top of the much harder bedrock. Soil erosion was a significant factor of the impacted ground area. Recent logging in the area also contributed to the erosion problem.  Soil that lacks vegetation and a complex root system is always more susceptible to erosion; be it from wind or rain.  

Rainfall: The Oso area usually receives on the average 6 inches of rain for the month of March. However, in the three weeks leading up to the mudslide the area had already received double the normal amount.  A long soaking rain is a far more serious concern because the ground will eventually become saturated, where a quick rain, even if it is heavy will runoff and quickly evaporate back into the atmosphere.   

Topography: Washington state is characterized by many steep slopes and hills. Areas and communities that are located at the bottom of slopes are more at risk to be impacted by slides. Also located at the bottom of the impacted slope is the Stillaguamish River. The Stillaguamish River played a significant role in the Washington mudslide because it had gradually eroded the bottom of the hill, which supported the higher ground.

           
            As you can imagine the soil and earth can only absorb so much water. When the soil becomes saturated, adhesion between the top layer of soil and the bedrock decreases. The bedrock becomes slick and slippery and eventually the top layer will separate. Therefore, when the rainfall is double the monthly average, the Stillaguamish River is going to run faster, rise above its banks, flood and erode away even more earth at the bottom of the hill at a quicker rate. When all of these factors align, the base of the hill will give out and a mudslide will occur.  

In closing, it is worth mentioning that most people think a mudslide runs from the top down, when in reality, a slide happens because the earth gives out at the bottom of the hill.  When the earth at the bottom can no longer anchor and support the earth on top, then a slide will occur.  The steeper the gradient or higher the hill, the more critical it is for the earth at the bottom of the hill to remain stable.  So, factors such as heavy rains, saturated ground, lack of a significant root system, past erosion and a racing/cresting river at the base of a steep gradient are all key factors for a mudslide to occur.

Graphic: Courtesy of The Washington Post

NATIONALS Opening Day Forecast

Washington Nationals vs. Atlanta Braves

Nationals Park (home opener)

WUSA9, MASN

1:05 pm

It's that time of the year again! The home opener for the Washington Nationals is today and ForecastGMU has the weather covered for all the fans! Cloudy skies and cooler temperatures are expected. There won't be any rain until after the game, so you won't be needing that umbrella. You'll want a light jacket though! Below are the conditions for the first pitch, as well as for the day in Washington D.C. 

FORECAST

First Pitch Conditions

Temp: 58

Wind: East 10 mph

Sky: Cloudy

Precip: None

Washington D.C. Weather

High Temp: 62

Wind: East 10 mph

Sky: Cloudy

Precip: After 7 pm