A change in the weather pattern appears to be on the way later this week! This change will cause temperatures to drop to near or below normal for this time of the year, thus giving our area a better chance for snow. What is even more exciting is that this pattern change could last for awhile which would keep temperatures cold enough to give us multiple chances for snow. This posting will take a look at the pattern change that is coming and the possibility, although pretty low, for snow later this week.
It will be warm the first half of this upcoming week with above average temperatures, but an upper level wave of energy will be dropping south from Canada into the Great Lakes region around Thursday bringing in cold air with it. The image below shows that 500mb heights forecast for Friday. The Great Lakes region is covered in blue which indicates the heights will be below average which indicates colder air will be in our region. I will discuss this in more detail in a moment since this is where we could get a chance of some snow.
This image represents the forecasted 500mb height anomaly for Friday morning. This image is courtesy of Penn State eWall.
Now this system alone isn’t going to change our weather pattern long term because it will pass through our area and move to the northeast back into Canada. However, it is important because it will mark the beginning of the pattern change and could produce waves of energy for our region while it is positioned in northeast Canada. The forecasted pattern change is well represented on the image below.
This image represents the forecasted 500mb heights for Friday evening (00UTC Saturday). This image is courtesy of NOAA Detroit/Pontiac Office.
First, I need to mention that I borrowed this image from the NOAA Detroit/Pontiac Office. It is part of an article that can be read by clicking here. This image represents the forecasted 500mb heights for this upcoming Friday evening. The pattern change is expected to occur due to a developing ridge that can be seen in the northern Pacific Ocean just south of Alaska. This ridge would cause blocking by preventing the flow of air to move through the ridge. As a result, the air flow will have to split and move to the south and to the north of the ridge. The northern stream of the split flow will cause a long wave trough to develop over the eastern US allowing colder air to continually flow in from our north. It isn’t certain that this pattern will develop, but if it does then it could last for awhile as blocking patterns can last for some time. It is also worth noting that the upper level energy that will be moving through our area on Thursday will be positioned in northeast Canada and could create new waves of energy that would drop south into our area giving chances of snow.
Now onto the chance for snow Wednesday night into Thursday. First I need to say that as of today, the chance is pretty low. There is a better chance that if we do receive precipitation then it will be mostly rain or rain/snow mix with no accumulation. However, the most recent model runs are showing hints that the system coming out of Canada could combine with another system that will be coming from the southwest. This would produce a stronger system and give this phased system more moisture to work with. The models have been very inconsistent with the interaction of these systems the past several days so only time will tell what will really happen. As it gets closer and the models start to agree more with each other on a possible solution then I will write another posting to update all of my four three readers.
Chris
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