After a quiet winter, the calendar turned to March, which represents the end of meteorological winter. However, Mother Nature has doesn’t always follow the seasons the way meteorologists have drawn them up. As we head into the first week of March, the cold air has certainly been in place. That is one of the few ingredients needed for a March snowstorm.
When you talk about a March snowstorm, there are several things that have to occur. Because of the higher sun angle and longer days, temperatures are often warmer, with the average high in the mid 40s. Therefore, you need cold air in place. For that reason, first, you need atmospheric blocking. What this means is that high pressure is located over the North Atlantic Ocean, allowing for low pressure to track up the east coast. This blocking pattern allows for pushes of cold air from Canada into the eastern part of the U.S. That has certainly been the place over the past few weeks. For example, Central Florida saw snow flurries on Saturday evening. So the blocking is in place, the cold air is in place, but you also need a progressive, stormy pattern. Well, that is in place too, as we continue to see low pressure systems move through the area on an average of almost twice a week.
Now, certain media groups have been comparing this storm to two previous storms, the Ash Wednesday storm of 1962 and the blizzard of 1993. For meteorologists, when analyzing a particularly strong weather situation, you try to find an analog, or a previous pattern that could help predict what will happen. While these two events may fit as analogs, there are also a lot of exceptions. First, the 1962 storm stalled for several days off the coast, allowing for prolonged periods of hurricane-force winds, storm surge in coastal areas and over a foot of snow. The storm brought almost 18 inches of snow to some places of Central PA. While this storm is going to significantly deepen and also slow down, it is not going to linger for several days.
The March 1993 storm, which is remembered by many in Central PA, formed in the Gulf of Mexico before it rode up the Atlantic coast, bringing over a foot and a half of snow to most places in Central PA. This storm also brought considerable coastal flooding due to its track and moved quicker than the 1962 storm, with most of its effects being felt over a 24 hour period. While the effects of this storm appeared that they could be similar when the upcoming storm first evolved, it now appears that metropolitan areas like New York City and Boston will see less of an effect, reducing the similarities to the 1993 storm.
We’ve talked about the setup and the comparisons, now let’s look at how the national media has forecasted this storm. First, it is safe to say that the hyping of storms has reached a point of no return. We have had the ‘snowpocalypse’, ‘Superstorm Sandy’ and now the naming of winter storms by The Weather Channel. All of this is appropriate if it promotes preparedness for the dangers of weather. However, if this hype is overblown and the forecast is a bust, well it leaves egg all over the faces of meteorologists.
Here at CBS 21, we will provide you an accurate forecast once all the information is available. There is no use predicting snowfall totals a week before a storm hits, because a ton of things can change over that time. For example, on Friday the National Weather Service posted a picture of what one of the forecast models showed for Central PA, which was over a foot of snow. First, the models have changed a lot since Friday, as is expected as you get closer to the event occurring. Secondly, as meteorologists it is important to look at all the guidance available, not just one model.
To the forecast. A low pressure system moving out of the Midwest will move toward the Appalachians during the day Tuesday. By Tuesday evening, the low pressure system will be located over the Central Appalachians, over West Virginia and Maryland. This will keep the heaviest snow to our south. However, everyone should get in on a little snow. To our north, there will be a sharp gradient where the snowfall decreases to nothing. Over Central PA, it looks like a range of 2-4 inches is likely at this point. The storm will deepen into a strong low pressure off the coast of Virginia. For Central PA, the sweet spot of low pressure formation is off the Delmarva coast, so once again it looks like it will be another near-miss for Central PA.
However, for those snow lovers out there hoping for one big storm before the year ends, there is still a chance this storm could come further north, which would bring higher accumulations to Central PA. Stay tuned, CBS 21 First Warning Weather will continue to bring you the latest on the forecast!