NY NJ PA Weather Forecasts

Nor’ Easter Becoming A Growing Threat

While high pressure will remain in control over the forecast area on Wednesday, the weakness to the south and east of the region that has been festering for several days will begin to show signs of development.  The contrast between the cool, dry air over the Northeast and Mid Atlantic and the warm, moist air over the Gulf Stream will produce a stationary front and an area for prime development of low pressure systems.  By Wednesday evening, a low pressure system will develop off the Southeast coast at the surface while a trough and later an upper level low will form over the coastal waters of the Carolina’s.  

This morning, I’ve been examining water vapor images of the short wave disturbance that will help to carve out a new trough in the East by next weekend and the week to follow.  The speed and strength of this disturbance over the north Pacific right now will dive towards the northern Plains by Thursday evening, however stay far enough north to only pull the developing upper low off the Southeast coast towards the forecast area.  Meanwhile, a strong upper low over north Atlantic, which is producing an impressive negative NAO structure, will prevent the surface low along the coast to exit east.  Thus, by Friday evening through Saturday, a strong coastal storm will approach the forecast area.  The strong thermal gradient coupled with the strong divergence aloft will allow this low pressure system to strengthen and produce a significant rain and wind event along the coast on Saturday and possibly into Sunday morning.  

The model guidance for this storm is still in a state of change, however the trend of all model guidance is clearly towards a storm along the coast next weekend.  How strong and the exact time frame is still debatable.