WxGuy1 wrote:Doesn't seem unreasonable to me, and I wouldn't call that "rapid deepening" if you are referring to the Great Lakes low? It bottoms out at 1010mb (per the 12z GFS), which is certainly nothing spectacular.... A surge of cooler air across the upper MS River valley and some WAA over the eastern Great Lakes will increase the thermal gradient across the region. Thermal wind relation tells us that this will increase flow aloft (which the models prog) and intensify the vorticity aloft across the central Great Lakes as this occurs. This vort max slides eastward with time, as warm-air advection continues across the eastern Great Lakes. There isn't a whole lot of support from transverse circulations in the upper-levels (though the surface low is near the right-entrance region of the upper-level jet streak), but the thermal and vorticity advection patterns make it plausible that a low (especially a weak low as the GFS indicates) will develop across the Great Lakes. Given the thermal gradient in place, I wouldn't be surprised if the low is going to be stronger than the GFS progs now, though the model can certainly quantify the cyclogenesis process much easier than I can!
Good points. Actually, I misinterpreted what I was trying to say. By "rapid deepening", I meant that the low showed a short but quick spurt of some deepening. I know it doesn't qualify as rapid deepening, nor do the synoptics and thermal gradient indicate it as rapid deepening, but it was simply a brain freeze while searching for as best a description as to what I was trying to describe.
I never said that an eastern CONUS/Eastern Seaboard landfall was likely, but that it was more along the lines of a 50/50 possibility in my opinion, based on my interpretation of the synoptics and viewing of model initializations and surface maps/loops. It was also an analysis of, if the 50% chance of an Eastern Seaboard impact occurs, which general paths might be most likely.
