either bonnie is shy or a tropical wave impostor has had us all running around screaming. but of course take a look at the satelite shots and note that the general appearance of the system has remained steadily good, and is somewhat better this evening even.. and that the wave is sharp to a hairpin and only open due to forward motion.. and that south america is inducing drag on the low level component of the wave.. yeah, it's still on.
rabbit will either get a carrot... or the holy hand grenade of antioch. as for me, i've got the options from last night narrowed down a tad. the system is keeping south and far less likely to pull that extreme recurvature if it gets it's act going.. the possibilities as i see them now are as follows:
1) system plows westward and never develops. dull, emphatic, familiar. 20%
2) system develops or fades in and out, continues generally westward, ditches in central america early next week. 20%
3) system decelerates, develops and hangs at the base of the trough over the weekend, is drawn to higher latitude, then continues west as the ridge comes back. 40%
4) system rapidly intensifies, recurves from incredibly low latitude for august.. essentially bonnie is a streetwalker and the gfs is a digital pimp. 10%
i'm still of the mind that the system is going to be a tropical storm, and am thinking of it as a potential player down the road for some place in the SE united states. my ideas are contingent on the centroid feature of the disturbance near 13/64 becoming the future core. the south american coast is inducing drag on the surface system, probably causing an e-w orientation to develop on the formerly n-s wave axis.. i'm fairly sure it will cause a low to close off. the axis appears to be forward tilted now.. that is my evidence. even though upwelling on the southern fringe of the caribbean is traditionally a choking mechanism for storms, in this case the ill effect is likely mitigated by the drag effect of land. the big problem with this idea is the 700-850mb level flow, which will keep stacking from happening easily.. good, strong convection near the centroid will be needed to give it a start. lots of contengencies, but i still think bonnie is around the corner.
nuff of that. alex has a 5.0 rating, and that was earlier. 00z-ish dvorak should be even higher.. i think alex is major as we speak. very good presentation, system has gone well beyond what i thought reasonable. globals now feeding the energy into a frontal system, though i think higher than average north atlantic ssts and current intensity will keep the system tropical through early saturday, and discrete from mid-latitude weather right up to the fringes of europe.
anyhow 92L behaving pretty much as expected. some convection persists, structure not decaying much.. and the system is getting closer to the solid support ssts. some shear ahead, but it isn't racing in the deep easterly flow, so it should manage. potential player, currently near 16/38. some of the energy is getting to the north, but shear up there is too robust to allow organization.
not much else in the way of present potential. some clutter behind alex under residual ridging and with decent convergence.. will be in the sweet spot of baroclinic deepening in a couple days, but going north/northeast if anything. minor concern regardless.
the t.d. 2/91L forecast challenge is still up til 10PM, even though the system is 'open'. it isn't as open as it would need to be for all bets to be off. there was an issue with the forecast times i'll go clarify over on the forum now..
HF 0020z05august