we're going to see development in the coming days... the key to where it all goes lies in the subtropics. i'll break it down.
two things aside from franklin need to be watched north of 20n. one is to the west, the other to the east. bastardi pointed out the southwestern feature on his TWO this morning... residual vorticity and an upper air sort of catchment will be stuck near the bahamas for the next few days.. as well most of the models forecast the trough heading to break the heat wave in the east to split and show a 500mb weakness retrograding over the southeast. these will be the focal point for interest as the 500mb low and dying front may trigger low pressure on the northern gulf coast, as well as the weakness near the bahamas interacting with the weak piece of tropical wave near 20/58 that split northwest the other day.
east of there is the potential storm-catcher. aside from the wave with invest 92L on it near 43w, subsequent waves may be passing underneath what may be a deep layer or hybrid cyclone east of bermuda. globals show a variety of different features but agree on a disturbance closing off near 30/50 in the coming days... diving shortwaves east of the 500mb ridge building in the western atlantic interacting with the persistent mid-level disturbance that has been east of franklin for the last few days should combine to trigger a low or hybrid system here.. which may provide a weakness for storms in the deep tropics to come north. depending on how it forms it may transition into a tropical-type system or attempt to lift out.. or simply stay relatively put and pull anything from the cv region poleward.
as for waves.. 92L looking about like yesterday. vortmax on the north part of the wave axis with little convection near 17n, weak low near 9n shifted south on the axis.. itcz embedded.. shouldn't do much until it gets a bit further west. globals propagate this feature wnw past the northern islands july 29-30... and into the bahamas around august 1-2. this one is a threat to the u.s. if it develops, in about a week's time.
wave behind 92L has more impressive convection... may develop further east. currently near 33w. the weakness in the central atlantic may draw this one up or at least tug it poleward.
new wave just coming off near 17w. another weeks worth behind it, probably more behind that.
trough splits and retrograding upper air features this year have triggered several of the systems we've tracked. the version of that going on near the east coast this week/weekend should make for an interesting scenario if a storm gets into the mix.
HF 0013z27july