Tuesday Morning Possible Rush Hour Mess

It is looking more and more of a possibility for some frozen precipitation for the Tuesday morning. A cold trough is beginning to descend over the middle of the country bringing frigid temperatures once again for a majority of the nation’s mid-section. With that trough brings a tremendous amount of energy that will cool off the temperatures dramatically Monday into Tuesday. 

Things will begin as rain Monday afternoon, but as the evening hours roll along, a large blast of cold air will leave temperatures hanging right near the freezing mark by the surface. With sufficient depth in the cold air in the upper levels, it almost does not matter the temperature directly at the surface.  As long as the temperature stays near or below the freezing mark, the possibility for sleet or freezing rain is highly likely in the morning hours. 

What will continue to be monitored is how the different ingredients of a frozen precipitation scenario line up. For example, most of the cold air will be due to a “blocking” high up north which will help pull cold air into the region while the moisture comes in from the southwest. Another factor is timing, whether the heaviest of the predicted precipitation is of the frozen variety (freezing rain, sleet or mix) or it is rain can have a tremendous impact on road conditions for Tuesday. Finally, and most importantly the vertical profile of temperature for this particular case can have a dramatic impact on what will fall from sky: rain, sleet, freezing rain, snow or a mix. 

The forecast now seems to point for mostly rain with the best chance of mix from 7am-10am, but this again could change. 

Rather than give a definitive forecast, we will just run through a timeline starting with tonight.

Sunday Evening/Night: Mostly clear skies, winds from the SSW with temperatures staying fairly mild. Low tonight of only 47.

Monday Morning/Midday: Cloudy skies will develop, though the temperature again will be mild for this time of year. High near 60. Winds will shift from out of the West to out of the Northwest (front starting to come through)

Monday Afternoon/Evening: Temperatures will sharply drop as the cold front will come through our region at around 5pm. By 7pm most areas around the region will have rain showers and temperatures will be in the low to mid 40s. Winds will pick up with gust of 25 mph possible. 

Monday Night/Tuesday morning: The big question mark of the forecast, whether or not a changeover to sleet will happen is very hard to tell at this point as it will come down to a difference of a degree or two in the end. For now anticipate rain continuing through the overnight hours with temperatures remaining in the high to mid-30s until 5/6am. At this point the radiative cooling near the surface may leave conducive conditions for sleet to start to fall. Roadways and sidewalks may be slick especially before sunrise. Temperatures will cool until sunrise with temperatures at 7am for Fairfax are to be at or around the freezing mark. Accumulations in the worst case scenario will be around a ¼ of an inch of frozen precipitation (Note: No Snow for this system!)

Tuesday Midday: Temperatures will warm slightly by the early morning hours and a change back to rain will be highly likely by 10am, with 1pm being the absolute latest time for a switch back to rain. The heaviest of precipitation is also predicted to be in those early morning-midday hours. This is something to keep in mind as this system develops. Temperatures will be stable in the mid-30s throughout the region (subject to change!)

Tuesday afternoon/evening: Rain may continue all day if the system lingers, which some models have as a distinct possibility. A slim chance of a change back to sleet or a freeze of the rain already fallen is a factor looking ahead to Wednesday. Though most likely this will end as a rainstorm as it had started. Temperatures again will remain in the mid to low 30s throughout the region.

Right now I will put this as Low Impact. But this very well change within 12 hours. I will put the chance of freezing rain and sleet at 60% for Tuesday morning. Of course the western sections of our region, especially those in higher elevation have a better chance of more sustained frozen precipitation totals. 

Another update will come either tonight or tomorrow morning. So stay tuned and I will be sure to keep you posted! 

Update! Pre-Thanksgiving Snowstorm Snow Forecast and Impacts

Update: 2:30 pm

Rather than update the timeline set in place. I will do my best to interpret and evaluate the models output that has been presented in terms of how Tuesday Night into Wednesday looks for this region and the rest of the Mid-Atlantic/Northeast.

A large 500 mb trough is stretched out across the entire country and with it brings in high pressure with a large amount of upper level divergence. This trough is expected to move through the Midwest and Ohio Valley Tuesday night into Wednesday. A separate cold front will move across our region late today into tonight which will cool down temperatures. Once the cold air starts to interact with the warmer waters of the Atlantic, a low pressure starts to form. Where this low forms and how it interacts with the cold air along its track up the coast is key with forecasting the precipitation forecast of the storm. There are several different situations that could occur that leave us with several different situations. I will do my best to explain each one and the probability of each of them occurring Tuesday Night through Wednesday night.

The low pressure system rapidly deepens off the Atlantic coast and moves in a nearly parallel pattern to the East Coast. Temperatures on Tuesday Night into Wednesday will remain in the middle to upper 30’s throughout most of the metropolitan region with higher ranges towards the western suburbs and warmer closer to the water. Precipitation will begin as rain during the late night/early morning hours on Wednesday. Soon though during the mid-morning hours into midday there will be a changeover to snow. Most likely this change over will occur at around the 11:00 am mark with the accumulation beginning around 1 pm. While dew points will be at freezing or below, surface temperatures will remain above freezing during the early afternoon hours. This will slowly change though as a small amount of cold air advection will bring in enough cold air to cool off the entire region leading to the changeover to snow. When and how this occurs throughout the day is truly dynamic so the difference between accumulation or not is really a matter of a minuscule shift in the rain snow line. Within this model, we could very well see all rain and just snow showers showing up midday without accumulation on the surface.

Situation #1: 

Accumulation amounts: For the western suburbs, especially right near the Blue Ridge, accumulations will be in the 3-6 inch range with higher amounts possible depending on when the changeover to all snow occurs. For the immediate metropolitan region though, a dusting to 1 inch of snow is expected with around a quarter to half an inch of rain expected also. This will be very wet snow also meaning it will melt fairly quickly due to the dew point being right near the freezing mark.

Impact (Low, Medium, High)-For our region I will put this situation as a Low impact as the amount of snow expected is nothing to warrant any concern. Using caution while traveling is definitely important in this situation, especially those who are traveling to the North and West where totals are forecasted to be higher and heavier due to colder temperatures. Traveling along the 95 corridor, expect minor delays mostly due to high volume, but weather shouldn't be an impact at this time.

Probability: Very likely. I will say this is about 80-90% chance of occurring.

Timing: While precipitation will start Tuesday night into Wednesday morning, the models are in agreement that the heaviest amount will occur between 9 am and 4 pm Wednesday. Most of the snow will move out by Wednesday night with lingering snow showers mostly to our west possible early Thursday.

Situation #2:

The models are not exactly in agreement over the snowfall amounts. There is a true possibility that this could be a Low to Medium impact storm even though it is relatively early in the season. Within the situation we are looking at right now, where temperatures are right near the freezing mark and a large swath of moisture from a low in the Atlantic will bring in precipitation (rain or snow) for the entire region, the probability of a “busted” forecast is very high. The GFS model right now has the low being much closer to the Atlantic coastline than the NAM and the Euro model has us getting more snow than both of those models.

It is really tough to forecast so far out from a winter storm even as there are so many variables that need to be set into place to properly say with any kind of certainty that snow will occur.

In this scenario of higher precipitation, the rain/snow line moves over the DC area early and temperatures fall near the freezing mark earlier than expected, thus leaving the amounts of snow higher. Roadways could begin having slush on them by the 3-4 pm time-slot and if snow stays in the region, rush hour will be also affected.

Accumulation: In this situation, the 95 corridor will be more affected by snow covered roads and the 3-6 inches of snowfall will shift to the East while higher amounts (6-10 inches) will remain to the North and West and lower amounts to all rain will be likely in the East of our region (trace-2 inches).

Impact: Low to Medium-Roads will be slippery in this situation, not high enough impact that you should plan on changing travel plans, but allow more time to reach your destination and anticipate backup and accidents along major roadways.

Probability: Not very likely 10-20% chance. 

Timeline for Thanksgiving Travel

Courtesy of Politico.com



Could we see our first snow of the season during the busiest travel day of the year? Yes, it is quite possible to see small snow accumulations. We will breakdown the timeline to keep you updated as we receive information!

Monday Night Nov. 24th
A cold front with a dry passage will pass over us Monday. Clouds will increase, but the colder temperatures will remain to the west of us, back towards the higher elevations.
Tuesday Night Nov. 25th
High pressure will move into the region and winds will shift from the north bringing in the colder air. Temperatures will drop approximately 10 degrees in some locations.
Wednesday Nov. 26th.
A coastal storm currently off the East Coast may bring some winter weather to the Mid-Atlantic region on the busiest travel day of the year. The coastal low will make its way up the coast on Wednesday. We will be monitoring the track of the storm. As for now there still remains some uncertainty whether it will take a stronger, more intense western track or the weaker eastern track. The cold front that passed Monday will interact with the warm waters of the Gulf Stream, which will allow the coastal system to strengthen (cyclogenesis). The moisture from the Atlantic will feed into this storm and provide enough moisture for precipitation.
As for now, we would like to say that a chilly rain will begin Wednesday morning. Our temperatures will reach their high during the morning hours. Highs expected to be just under the 40 degree mark. Temperatures will then begin to drop throughout the afternoon. The freezing rain will shift over to snow in the afternoon. The actual accumulations are still uncertain, as models remain in a mild disagreement. This coastal storm will leave just as fast as it arrived. Snow showers will wrap up by Wednesday evening; although don't be surprised to see additional snow accumulation after the system passes.


Safe Travels Everyone!
-Katie

KeystoneXL-Why Should You Care?

We need energy. Our lifestyle requires energy sources. Energy that is affordable, cheap, reliable and dependable. Energy to run our appliances, heat our homes, power our modes of transportation, power our industries to make the products we love and enjoy, and even to produce our food that we eat. So where do we get this energy. For the past 150 years, this source has been of fossil fuels. They are called fossil fuels because their energy comes from an elongated process of breaking down once living material into a state that now produces power when it is heated. These fossil fuels are namely oil and coal, with natural gas being a highly sought after secondary source. These materials practically run the world and the source of the world’s achievements and of its conflicts.

Energy Budget for the United States

            The issue at hand though is that these sources of energy have negative consequences to them. Whether we like it or not, these sources do grave damage to the ecological, biological and environmental systems at the very least due to their harmful repercussions of producing them. To make a coal mine, a whole swath of land has to be completely cleared. This of course can kill off entire areas of plant and animal population, sometimes semi permanently.

The same goes for a technique of extracting natural gas called fracturing or “fracking” which breaks up the sedimentary rocks deep under the ground to release the gas out for consumption. This process, while proven more cost and energy efficient based off of the new high demand for cheap gas, also has some negative effects including contamination of the ground water supply which can kill off plants, livestock and even harm people directly.

Fracking is a becoming a more efficient way of extracting gas 

            The problem that presents itself is how we balance the two demands, energy necessity and protecting the world we live in from harm. Lately efforts have been put into place to promote green or “carbon neutral” energy to help alleviate some of the burden put onto the environment. While these efforts are helpful, they do not get close to solving the conundrum over energy. It is quite simple when spelled out though.

            If we want to keep safety in our economy and in our immediate future, we keep our production high for natural gas and oil. Most of our oil and gas gets sold overseas, thus lowering the price of gas here in America (why gas prices are dropping). Energy prices will stay relatively balanced with coal and natural gas again in the short term. This is the platform that many choose as they see shortsighted in this issue and point to economic stability and job production as a main concern for the welfare of the country as a whole.

            The other side of the coin is that our decisions we make today add up. It is not like if we emit more and more carbon dioxide, it will just go away. That carbon dioxide has to go somewhere. Notice how I have not even mentioned about global warming and climate change until now. That is only part of the equation. One of the hardest thing for people who support fossil fuels as a main source of energy to swallow is that these sources are temporary and non-replenishable. Once they are gone, they are gone forever. So clean energy is not just about saving the environment, it is about sustaining ourselves for the future to come.

Carbon Dioxide variations with time.
Notice the sharp unprecedented rise since the Industrial Revolution. 

            The Keystone XL Pipeline is a planned pipe that will go from the middle part of Alberta, down the Great Plains into the United States. The pipe will be mostly underground and will carry the oil from the tar sands in Northern Canada, south to the United States. The pipeline itself when completed will transport over 750,000 barrels of petroleum southward.  The Keystone pipeline has already been built, stretching from Canada down through Nebraska (there is an issue with that, read more about it here) and into Oklahoma. The KeystoneXL is merely a shortcut proposed that will have the pipe go through Eastern Montana and South Dakota making it more direct. The project of extending and finalizing the pipeline so that it connects to the Gulf Coast currently being discussed by Congress and is being proposed to move forward very soon. There have been concerns on both sides, namely the left about the safety and economic stability of such an investment.

Planned Keystone pipeline including the current pipeline as it stands (Washington Post)

            There is no doubt that the pipeline will require thousands of jobs and man hours to complete, so the argument that it will create jobs is not refuted. The estimates have it that over 40,000 temporary jobs will be created in result of the project being passed. Also if we decide against building the pipeline and the oil was left in the hands of Canadians, the demand for this petroleum would cause it to be used either way eventually. Also in the grand scheme of things, the pipeline would not directly contribute to climate change, as the extraction would be a small fraction of the emissions we already produce.  It also would be much safer than the current means of transport of oil, which over land is mostly by outdated railways. The EPA and State Department have reviewed and approved much of the process of construction of the pipeline.

Protest for the KeystoneXL

             The argument against is definitely more complex. It involves what if’s and situational concerns in the long term. It starts with extraction. However one plans on extracting the oil from the tar sands, environmental concerns arise. Either by pumping steam into the sands or strip mining them, the devastation will be all too noticeable.  Boreal Forests in Canada are already in danger; this would only speed up their process. The possibility of major leak is not if but when. The damage caused is not only environmental as the process of extraction releases more carbon dioxide than the normal production of oil. This in itself could be responsible for a temperature rise globally of over 2 degrees. Hundreds of thousands have protested against the pipeline in large scale fashion in the past several months.

Example of a protest against the pipeline in front of the White House

            From an economic standpoint, the jobs gained by this pipeline are not sustainable. This will mean a sharp crash after the pipeline is completed. Most of the money gained from the oil production will go to the companies themselves and to the pipeline company TransCanada and not into the US economy. The climate crisis currently is directly or indirectly responsible for billions of dollars of damages and hundreds of thousands of jobs lost. Eventually this will start to put a huge damper on our GDP and affect the global economy. We as a country should focus on more sustainable job growth, both from a green and economic level so that we can ensure success for generations to come.

A scary before and after photo of how Alberta would look after oil extraction

So why should you care? Well because it is your future. The general population's knowledge on how policy decisions is an integral part of how we can actually change the world for the better. Do your best to research these issues and try to form your own opinion rather than relying a news station or other people to do so. President Obama has taken large criticism for being too lenient on the issue. Liberals feel that with the way that the issue is shaping up, the final decision might come to him. Conservatives fear that the economy will be at risk of further turmoil if this pipeline does not get built and that environmentalist are just stalling progress.

 So what do you think? Yes or no to KeystoneXL? Comment with your opinion.

Lake-Effect Snow Blasts Buffalo, NY

By now I am sure you have seen the incredible photos of record-breaking snowfall in the Lake Erie snowbelt. Some locations have seen anywhere between 3-6 feet of snow from one storm. You may have heard this is the result of lake-effect snow. This region is no stranger to lake-effect snow, so why is this snowstorm being coined “the worst in recent memory”?

To begin, lake-effect snow occurs when cold air moves over the warmer waters of the Great Lakes. As the system moves over these large bodies of water it picks up water vapor, enriching the air with moisture. It then freezes and descends on the leeward shores.

What makes this event the worst in 40 years?

(Photo/ Twitter User @JeffreySuhr)

The wind direction and temperature difference are the major influencers to the extreme amounts of snowfall that we have witnessed. The wind plays a prominent role in this weather dynamic because of the constant direction the wind blows during a storm. Since the wind direction did not change, locations, like Buffalo and surrounding counties in western New York, received the brunt of the snow bands. The sizeable temperature difference of the frigid air aloft and the warm surface water provide an unstable atmosphere optimal for rapid snow production. It is typical for November snowstorms to produce large snowfall totals because the lake temperatures are relatively warmer than the latter months of winter. This provides a larger temperature differentiation. Also, the air aloft is warmer therefore allowing it to hold more moisture and yield more snow. Some locations in south Buffalo have witnessed thunder snow. Buffalo has not seen this much snowfall within such a small timeframe in 40 years!

So what happens next?

(Twitter User @TrainerAmyIndy)

This lake-effect snow event is forecasted to occur in two rounds. The first round of snowfall started this past Tuesday. The second round of lake-effect snow resumes Thursday. Overnight Wednesday, snow bands regenerated over the warm Great Lakes. Snow will continue to fall throughout Thursday; another 2-3 feet of snow is expected for the Lake Erie snowbelt region. Some locations will begin to see snow taper off as early as Friday, whereas other locations will have to wait until Saturday to see the snowfall diminish. Over the weekend snow may transition to rain as temperatures raise above the freezing mark, which will bring up another major concern—flooding. While the snow melts, flooding will become an issue. With over 6 feet of snow already on the ground in some places, the average person is having trouble removing the enormous amounts of snow that have already accumulated. As you can see from photos, the ordinary snow blower and shovelers are in way over their heads.

(Twitter User @HowardManges)

         This storm system has unfortunately turned deadly. Photos show how the power and weight of the snow can actually burst through doors and windows. Residents have to also worry about roof collapses due to the tremendous weight of wet snow. The Mayor of Buffalo has warned citizens to not be fooled by the break in between rounds and issued a driving ban for all nonessential vehicles. The snow has already resulted in ten confirmed deaths. The Governor of New York has declared several counties in a state of emergency and the National Guard troops are in place to assist with snow removal and rescuing stranded motorists and homeowners who can’t dig out.

Here are some more incredible photos!

Major highway covered in snow. (Photo/ Twitter User @NYGovCuomo)

Photo Credit: Kassie Tamulski

(AP Photo/Gary Wiepert)

West Senaca, Ny (Photo Credit: Jessica Marie)

-Katie

Explaining the "Polar Vortex": The Most Misused Weather Term of 2014

Courtesy of ABC News

It’s that time again. What time is that you may ask? The time of the year when extremely cold air that comes into our region is labeled a Polar Vortex.  Around this time of year, the media can sometimes go into a frenzy, repeatedly using this term. However, many times the word is not used correctly. So what exactly is a “Polar Vortex”?  

First off, the Polar Vortex is a low-pressure system that continuously circulates year round in the Arctic and Antarctic regions. It is worth noting that the Polar Vortex in-fact exists during the summer months; it’s just not as strong as it is in the winter. It extends from the middle troposphere (0-11km) into the stratosphere (12-50km) and rotates counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. The reason why you hear about it in the winter is because the center of low-pressure circulation strengthens in the wintertime. Occasionally a portion of the Vortex will migrate southward, which was the situation last week. In that scenario, the Polar Vortex weakened allowing a portion to migrate from the north into regions further south and gets absorbed into the jet stream. When this happens, portions of the United States experience dramatic episodes of cold air outbreaks. A further extreme situation is when the circulation of the Polar Vortex starts to collapse. As it collapses large portions of cold air break free and affect our region. This is what occurs when we have historic/record breaking Arctic air outbreaks, like we had last January. High winds can often accompany a Polar Vortex.

Courtesy of NASA

A large part of forecasting these Arctic air outbreaks is looking at the positioning of the jet stream. In the wintertime, the polar jet will dip further south than normal. The strengthening of the jet stream brings frigid air into a region of traditionally warmer air. This is a significant factor in the deepening and strengthening of low-pressure systems. These downward dips in the jet stream accompanied with polar Arctic air are important ingredients in fueling winter storms. During this event, the jet stream acts as a boundary between the cold, polar air masses in the north and the southern tropical air masses. The warmer air mass to the south is moist; and when it forms a front along a cold, dry air mass, strong winter storms are possible. The warm, moist air mass rises over the cold front allowing the moist air to cool. This is a key ingredient of the precipitation process. When precipitation begins to fall, the colder air mass at the surface provides the cold, frigid temperatures needed for frozen precipitation to develop in the form of snow and frozen rain.

          

          Hopefully, this article was able to clear up some misconceptions you may have had about this unique, but often misunderstood weather pattern. Every cold snap is not a product of a Polar Vortex. It is very possible for our region to experience a cold blast without it being accompanied by a Polar Vortex. It’s often that we are just under the influence of a polar Arctic air mass. Finally, when you do hear a forecast with the Polar Vortex, remember there can be varying extremes of air circulation. A weak vortex is much different than a collapsed Polar Vortex where a cold air mass is very large and temperatures significantly drop. Don’t always assume the worst, but it is still prudent to be prepared for extreme cold weather during the winter months! 

-Katie