We have been talking about an upper low off the east coast of the United States that has been sitting there for the last several days and this afternoon’s model runs were all very interesting in that they all develop some sort of surface low off the east coast over the weekend. Above is the Canadian model for Saturday evening. Other models below have a similar idea with the surface low offshore and strands of convection scattered all around the surface system. The European is for Saturday morning since there is no map publicly available for the matching time frame but it has the same scheme.


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What does this all mean? Well when it comes to cold core to warm core transitions the models are usually slow on the uptake but the fact that they all have something off the east coast warrants attention in my view. Satellite pictures and the loop show the system with convection that developed during the day. Usually what happens with these systems is that the thunderstorms fire up during the day in the cold core environment and then wind down and disappear at night only to fire up again during the day. When the transition is taking place the thunderstorms do not disappear at night so we will be watching tomorrow morning to see what exactly we have. To see the loop click on the picture below.
satNow should this system develop into a tropical cyclone based on what we are seeing aloft it would not at this point be something that would be drawn to the coast. However if it does we will see some impact to marine interests over the weekend with increasing seas, rip currents and so on. The Canadian model is interesting in that it tries to back precip in from the east over the weekend. The look is non tropical in nature so if that is the case I could envision a scenario where some precip does back in from the east on Sunday. gem78We will of course be keeping a close watch on this going into the weekend in case we have to add clouds and precip into the forecast for Sunday.