NY NJ PA Weather Forecasts

The Key Positions Of Ridges And Troughs

As you may have read, I am not all that impressed with the potential for a Nor’ Easter this weekend.  The thoughts on this potential are covered in the technical forecast discussion.

I do want to point out though that I think the theme I am discussing today will become a key issue this winter for storms along the coast.  The position and strength of the ridge over the Western United States and the state of the North Atlantic Osscilation (NAO) will be key this winter.  I am expecting a weakening Pacific jet stream this winter, which should allow for a ridge to develop over the West.  However, the teleconnections that seem to continue to show up to this point can be dated back to the position of troughs and ridges over the western Pacific.  The trough that develops over Japan has the axis of the trough over the Japan Sea.  The progression of this large scale wave would suggest a trough axis along the East coast.  The position of the trough axis slightly off the coast has lead to a compel of close calls already.  Note the storm that has potential to develop off the East coast in late September and the potential storm for this weekend.

Now, there are indications of the Pacific setting up so that the ridge, trough positions would focus storms closer to the coast line.  I am watching the changes in the Pacific and the Indian Ocean very carefully and it is these changes why I am holding off on issuing the winter forecast at this time.  

I do think that there will be a better chance for storms along the East coast this year.  The question now comes into whether the position of the troughs and ridges will allow the storms to develop close enough to the coast. If they do develop, will a progressive pattern from a weakening PNA ridge allow the storms enough time to develop.  These questions are still unresolved and will likely be the main questions through the winter.

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