Today on the satellite we see a complex pattern setting up. First off, we have what was hurricane Rafael churning in the North Atlantic, which is making the 500 mb pattern over North America slow down
We also have a developing upper level disturbance slowly approaching the Great Lakes , and we are already seeing moisture feed up the east coast from this developing storm system.
Over the next 48 hours, the upper level disturbance over the upper mid west will dive SE and strengthen as it interacts with the sub tropical jet stream, meanwhile , high pressure moving off the coast will lead to a developing SE flow off the Atlantic right into the Northern Mid Atlantic.
For today and tomorrow dry conditions are expected with slowly increasing clouds, highs today in the upper 50s to low 60s are expected lows tonight around seasonal levels with low 40s NE PA to upper 40s low 50s along the coast and Thursday will be a bit warmer with strengthening southerly flow with highs in the low to mid 60s NE PA to mid to upper 60s along the coast
Thursday night is when things get interesting. The upper level disturbance will be impressively strong with gusty SE winds developing, meanwhile an occluded front will develop and extend into the southern Mid Atlantic states
Thursday night skies will become overcast with a slight chance of showers late at night and going into Day break Friday. Friday will be humid with highs in the low 60s NE PA to mid to upper 60s along the coast.
As the storm system begins to move NE through the eastern Great Lakes, the occluded front will come NE as well, and along this front will be a band of heavy rainfall that will slowly move through the forecast area and intensify as it interacts with Atlantic moisture, along with gusty SE wind 15-25 mph. This occluded front will approach Friday afternoon and evening, during the morning hours on Friday and early afternoon hours, showers will be a threat but the steady heavy rain should hold off until late afternoon hours and I cant rule out a thunderstorm
Friday afternoon /evening
The front will exit Saturday morning with steady rain ending although showers will be a threat until the mid afternoon hours before the cold front comes through
Overall the area can expect 0.50-2.00 , with the least expected over southern NJ and Philadelphia metro (0.50-0.75) the most being in Northern NJ/NE PA and NYC metro (1-2 inches) could be locally more if the front slows more than expected
We will cool down behind this storm system on gusty NW winds Saturday afternoon through Monday with highs in the upper 50s NE PA to mid 60s along the coast and lows in the upper 30s NE PA to mid 40s along the coast
We will warm up again as the EPO goes positive and a trough drops into the western US thus pumping up a ridge in the east Tuesday through Friday with temperatures expected to be above normal with highs in the low mid 60s NE PA to upper 60s low 70s along the coast and lows in the low 40s NE PA to upper 40s low 50s along the coast .
A cold front will come through somewhere between Friday and Sunday of next week and make its presence known as we will get MUCH colder behind it as the trough swings east and gives way to a ridge building in the west. Overall over the next few weeks going into November , this is the pattern I expect, a lot of ups and downs as the EPO flucuates from negative to positive etc.