The temperature's will continue to get colder as the ridge exits the region and arctic air filters in from Canada. On Friday the highs should be a chilly 15 - 20 degrees below normal for the highs. For the weekend the temperature's could go up but highs will still be a good 7 - 12 degrees below normal. For the weekend we should have mainly dry conditions except for Sunday when a weak system will fly through New York and Pennsylvania possibly producing light snow accumulations, but this is still 5 or 6 days away so time will tell. Now, here comes the very interesting part of this forecast post.
On Monday there could possibly be a very big snowstorm across the northeast that if this event plays out will come from the midwest. Temperatures for this possible event would be cold enough to produce snow except for possibly extreme southweastern Pennsylvania. But anyways this storm could be a huge storm and I wanted to show you a few models from the gfs runs. So below is the 00z gfs rum from today, Monday.
Here is the 00z gfs model graphic at 204 hours. As you can pretty much see there is a big storm centered in extreme southwestern Pennsylvania. Also this storm has a very good size precipitation shield. Next a key factor also sits on the nao and what phase that will be in. The nao looks like it will be in a neutral phase which would most likely mean this storm would move west to east. However storms as we know can move in other directions but that is the average track of a storm. So you might be noticing that 540 line is pretty close to the northeast. Here is the temperature graphic that is from the 00z gfs as well.
So here is the temperature forecast at same hour as the precipitation graphic was at. Now, you might be looking at this and notice something pretty big. Southwestern Pennsylvania is possibly too warm to snow, but this is still far out, but anywhere else is fine. Now below is the same model but now 12 hours past, this is at hour 216.
Now we have a big storm off the coast that is spreading heavy moisture as far inland as central Pennsylvania and southern New England. Next you see the 540 line is also way farther south then the graphic before of the precipitation. Now here is the temperature forecast from the 00z gfs or the same hour of the graphic directly above.
Now the temperatures have fell significantly across the entire northeast region. These temperatures combined with snow would be equivalent to very good snow ratio's. You see teens as south as extreme northern Maryland. This is very cold. So you really might be wondering, so how much snow could be possibly see out of this possible snowstorm event. Well here is the same model, the 00z gfs snowfall graphic for this storm. Now be sure to read on after this graphic because these will probably not be the real totals of this storm because of just how cold it will be.
Now to start I just want to say, the snow that this indicates for area's like Somerset, Pennsylvania to Pittsburgh will already be on the ground in most spots in and between those two cities. Now the snow that this shows for central and eastern Pennsylvania as well as New Jersey is fresh. Now this shows what you think is just 4 - 6 inches for these area's, right? No, because it will likely be so cold and the ratios will be so high, you can multiply these amounts by about 1.5, so that 4 - 6 inch range is really about 6 - possibly 10 inches. Although this possible snowstorm is still far out, it's not as far out as you think, today is almost over so Tuesday this almost here, from Tuesday you only have 6 days until this possible event. But many model runs show this storm or hint toward the development of this storm. So keep here for the latest updates on this possible storm and other weather events.