Big Storm Next Week: But Will It Be All Snow?

Good morning. A large storm will effect the eastern 1/3 of the country next week. As I mentioned yesterday this storm will carry with it a large amount of moisture due to it originating out of the sub tropical jet stream. It will develop in the Gulf of Mexico and move northeast right into our region. Ahead of this storm there will be cold air in place. The million dollar question is how strong is the cold air in place, meaning will it hold its ground and also when does this storm phase with the polar jet stream. If the storm phases too early then it will wrap up warm air from the south into our area resulting in a snow changing to rain scenario. If the two disturbances phase later then we have a very significant snowfall possible. It is almost impossible at this time to say what scenario will occur, we can only speculate. Lets take a look at the features.

Below you will see the two disturbances I am talking about..

Ahead of these two approaching disturbances here is the cold air due to an arctic high over our region..

Now if those two disturbances combine too early you get a a southern flow on the eastern edge of the storm this pulls in the warm air as you see on the next image...

This would result in a snow changing to rain scenario as the cold air gets overtaken by the southwesterly flow of warm air due to the placement of the low pressure center to the west of our area. You always want to be on the cold side of a storm which is the western edge of the low pressure. 

So here is the forecasting issue, no one knows when those two disturbances will combine, thus it is very hard to predict if we will see all snow or snow changing to rain for our area. Some model runs have kept North Jersey in all snow, while others have not. This will continue to flip flop over the next few days so no one can get caught up in one model run. The main point here is that someone is going to get a lot of snow with this system,  most likely over a foot. In addition, there is another similar storm that could develop on its heals and give us a 2nd shot at snow. The pattern is extremely active right now, we just need to have a little luck on our side if you want snow. If I had to make a call right now here is what I think, and again this is purely speculative but this would be my first guess based on how I think things will trend...

More updates later tonight.