ThetaE wrote:Emmett_Brown wrote:Glancing at recon wind barbs, Ian still looks like sharp trough axis. Currently the "center" is actually an elongated ellipse from 13N to 15N along 75.6 W, so no real west winds yet. The northern vort along the axis has lower pressures, so that could be where his center ends up.
This is true at the mid-levels (well, at flight level-- 850mb, still pretty low), but clicking through various dropsondes reveals that this northern spot is the location of a pretty robust low-level circulation. Winds still shift with height in the dropsonde profiles, and the drops SW of the recon-marked center have a far more westerly component near the surface than aloft. In addition to being the location of lowest pressure, this center also seems to be consistent with where the (naked) LLC got sucked into the convection earlier this morning.
The flight level winds to the south seem to be the remnants of the convection displaced from the LLC yesterday, and so I'd argue (given the lower surface pressure and the more vigorous convection to the north) that this southern wind shift isn't long for this world.
This is not an easy thing to visualize, so I went through each dropsonde and annotated the map with the surface wind barbs. The LLC may be a bit elongated to the south, but I think it's pretty clear where the strongest low level vorticity is.
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