ATL: IAN - Post-Tropical - Discussion

[ScottNAtlanta]

The top one is what NHC is following, and the bottom is the only wind shift I've seen thus far

[NDG]

Webb has been saying how Ian sliding west reminds him of Ivan, well the similarities are definitely there

https://s4.gifyu.com/images/Ivan.gif

I get what he's trying to say but there was a completely different set up, Ivan was kept steered to the west by a stronger Bermuda ridge in the western Atlantic Basin into the eastern US, there was no strong trough coming down the eastern US like currently being forecasted.

https://i.imgur.com/H0viQx8.gif

I agree that the setup is slightly different but we do have a strong ridge steering it west

https://i.imgur.com/tAS1x37.png

Nope, it needs to be centered more to the N and NE of it and pushing west ahead of it to take the place of the trough digging over the eastern US.

[ScottNAtlanta]

The only problem with the northern center...is it doesn't really look like a center

[NDG]

The top one is what NHC is following, and the bottom is the only wind shift I've seen thus far
https://i.imgur.com/gJHAYd1.png

Down there where you are wondering about the wind shift the pressures are higher.

[ScottNAtlanta]

The top one is what NHC is following, and the bottom is the only wind shift I've seen thus far
https://i.imgur.com/gJHAYd1.png

Down there where you are wondering about the wind shift the pressures are higher.

Actually...the plane just dropped a dropsonde and it read a pressure 2mb lower than what they extrapolated. Plane was 1009, and the dropsonde was 1007, and if the are off 2mb at the shift that would bring it to 1006. I wish they had done a drop there

[Emmett_Brown]

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.

[MBryant]

Please forgive me for not keeping current. I was just wondering if disagreement between models has any correlation to disorganization in development and eventual lower intensity.

[ScottNAtlanta]

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.

I think we will know a lot more when recon completes this pass. Looking at the satellite there isn't much of a strong westerly inflow either.

[tolakram]

Visible floater https://weather.cod.edu/satrad/?parms=meso-meso1-02-96-1-100-1&checked=map&colorbar=undefined

[Kludge]

Please forgive me for not keeping current. I was just wondering if disagreement between models has any correlation to disorganization in development and eventual lower intensity.

Had you kept current you would be just as bewildered as most of us now. It's hard to give credence to any model right now that doesn't have concrete evidence of a specific CoC.

[Aric Dunn]

figured thats where it was. as I mentioned earler.. they need to focus on the 13.5- 13.9N and 76w ish area.

[toad strangler]

Please forgive me for not keeping current. I was just wondering if disagreement between models has any correlation to disorganization in development and eventual lower intensity.

That plus it’s still too far out for this type of approach. You’d have to be not honest with yourself if you think the pendulum of shifts won’t come back East again at least one more time. Especially if you consider wxman57’s comments from the past few days.

[tolakram]

saved loop.

[Abdullah]

We got a plane in there to tell us the real intensity of the storm but it's worth mentioning that its satellite presentation has improved considerably over the past few hours. We got "ADVANCED DVORAK TECHNIQUE, ADT-Version 9.0, Tropical Cyclone Intensity Algorithm" run by the University of Wisconsin showing a 999mb / 47kts estimation as of the latest numbers and steadily increasing. - https://tropic.ssec.wisc.edu/real-time/adt/odt09L.html

[SoupBone]

figured thats where it was. as I mentioned earler.. they need to focus on the 13.5- 13.9N and 76w ish area.

I'm curious about stuff like this. Do these pilots have people back at HQ recommending areas to look for the center? Or are they actively doing that while flying? I've been on Kermit twice, and I recall the dropsonde cannon and other monitoring equipment, but I don't recall what else they had on board.

Seems they occasionally miss areas that maybe they should have checked out.

[wxman57]

Minor changes to Ian's position now are not so significant. Major weather feature will be a deepening trof across the central and western Gulf this week. No matter where Ian tracks in the Caribbean, it's not crossing the upper wind flow. That flow would take it to Florida. 12Z GFS is smoking that crack again. Worst model for this storm.

Seeing you post this is pretty awesome and hilarious. I'm still concerned with these west shifts as it puts more of Tampa under a larger storm surge.

If you're in Tampa, don't look at the 12Z Euro run. It hates Tampa. For now, I wouldn't rule out Ft. Myers, nor would I rule out Apalachicola. North of Tampa looks like the spot.

[floridasun]

i not sure if you seen this or post already look their maybe new center to north of early one this from hurr hunter
that now in storm https://twitter.com/AndyHazelton/status ... 9966127106

[Aric Dunn]

Definitely still coming together. probably even another vort farther west with the new convection.. it can jump around pretty easily when they are loose like this.

[ThetaE]

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.

[Aric Dunn]

Ok yep.... we are going to get a jump well to the west with the convection firing.. recon shows a much larger SE flow into that area.. everything to the east is likely small meso vorts.. interesting.