Pre Thanksgiving Storm System 11/27/13 Early Call

We been talking about this system a lot on facebook over the past few days and posting the various model runs. We have seen from the GFS multiple tracks of the low pressure area and multiple scenarios played out from an all out snowstorm across the east to an out to sea scenario to a heavy rainstorm. The GFS has now fallen in line with the rest of the guidance ..such as the European Computer Model , the GGEM or Canadian Model and the British model  aka the UKMET. All these models, outside the GFS have been showing an inland runner travelling northwards across East Central PA .. Folks lets be clear about something ... when you have this type of track in the heart of the winter you would NOT be looking at a snow storm for those that are in the track of the low or east of the low pressure . We are not in the heart of winter so this holds true even more so. 
In order for this storm to come up the coast it means that the heights have to rise and when the heights rise it means the southeast ridge flexes its muscle and warm southerly winds are ahead of the storm system. Hence those east of the low or in the path of the low are in the warm sector of the storm system and would be looking at very heavy rain.
Lets look at the guidance tonight and we will look at the GFS first ...

Now, even on tonights GFS model the model is still running to the east of the rest of the guidance..but never the less you can see the warm sector and you can see the rainfall that occurs and how the snow is well inland..

The above is the GGEM and once again you can see the inland track that would take this low across east central PA and then into central NY..
UKMET is also showing an inland runner..

And finally the ECM ...

You can see on the ECM @ 48 hrs that the 540 line is well to the west and the 850 line or the black line in the lower right hand image is across the PA/NY border and then by 72 hrs the 540 line shifts east along with the 850 line. You can also see how inland the low is . So while the in between frames are missing ..the low pressure area would travel inland much like the GGEM/UKMET models and this would as we explained above cause the heights to rise and the SE ridge to flex its muscle and put those east of the low into the warm sector.
There is simply no guidance to support a SNOWSTORM in E PA or NJ... Now as the arctic front crosses the area if there is any moisture left behind the front that is when the region to the east could see some snow occur..but for the most part it will be rainfall ...

So for Now we are taking a blending of the models and we came up with the following scenario..

Now the one thing that all these models have in common is the tight isobars around the area of the low pressure. This means that there is going to be strong and gusty winds involved with this system.

The other aspect will be the heavy rains for those areas that see majority rain.