Windspeed

We'll have a dropsonde and sampling of the NE quadrant in mere minutes.

Recon about to make SW to NE pass. We'll know intensity very soon.

Wow... And just like that, a strong CB went up in the eastern eyewall and is rotating around in the northern semicircle. This has the look of a strong Category 3 hurricane. Need recon.

There's about 8-10 kts of southerly shear. Relatively too weak to prevent intensification but perhaps enough to keep downshear convection weaker as CBs go up and rotate around the eyewall. As Delta turns more northward and gains forward motion, there will be a window tonight (6-12 hrs) where shear is weakest prior to an increase in SSW VVW flow and mid-level shear prior to landfall. That and cooler SSTs should eventually put a halt on whatever intensification is gained by Delta through mid-day tomorrow. That should be prior to landfall.

lol..

Here's an animation of the classic NHC AVN IR colorization...

Heh, was I analyzing frame by frame? How about noting the obviously clear symmetrical eye at the end of that animation and obvious continued improvement. You know, the first clear eye we've had since Delta existed?

963.2 EXTRAP on last pass.

¯\_(ツ)_/¯

Likely response of an intense convective plume going up in the northern to western semicircle creating subsidence in the SE region of the core. That may just as well wrap shortly. Either way the overall structure has improved significantly since early this morning. Recon is about to make another pass. Should know more in just a bit.

Continuing to improve. Really convenient when big structural changes occur during daylight as nothing beats visible.

Eye is showing signs of warming and the high cirrus are starting to respond with dissipation. You can see the sinking motion. Banding / convective plumes in the eyewall are continuing to go up and they look symmetrical as well. All systems go...

Look for an area along the coast to increase in surge height if Delta really gets going by this evening. I think the 7-11 ft could be increased to 12-16 right of the forecasted point of landfall. The 7-11 may be extended further east of that increase as well.

Ike was dealing with significant ENE'rly mid-level shear as it traversed across the north-central GOM. It wasn't enough to force weakening but after Cuba, Ike also had a large circulation. If you will recall, there was an intense westerly eyeband that could not wrap or stay wrapped for symmetry. The convection remained lopsided but intense enough to keep the large circulation chugging along as a big Category 2. Simply put, the battle between shear and thermal dynamics kept Ike at status quo all the way into landfall. Obviously surge was the issue and led us to a new parameter, IKE. Delta on the other hand should have a good window of much more favorable conditions to actually reattain major status while continuing to expand its convective envelope symmetrically up until moving over cooler SSTs and mid-level shear increases prior to landfall. Granted, the end result may be similar for landfall intensity, but Delta's maximum winds should get higher than Ike's maximum winds ever achieved in the GOM. This all being said, surge is going to be the biggest problem at the coast regardless if it maintains Category 3 or weakens to a 2 by landfall. Expansion and fetch will have already been achieved.

This is quite noticeable on visible after daybreak. This looks like core convection is consolidating an eyeband. Perhaps Delta finally gives us a clear eye by this evening.

RE: 6z ECMWF; I think it is overdoing it little but it is worth picking up on why. Delta has yet to pass through the best upper divergence and lowest shear it will have in its existence. That begins this afternoon and continues to just before landfall when SSW mid-level flow begins infringing on the core with dry air. That and cooler SSTs should have it weakening significantly into landfall. Whether it is a Cat 3 or a 2 at landfall is a bit trivial as weakening storms do not always mix down winds as effectively as strengthening storms at the same category. The big story will still be the surge Delta builds up this evening and pushes into the coast with a larger circulation.

Best upper tropospheric support to get the most out of the heat content will be this afternoon. That is when I expect significant intensification to begin. Modeling also suggests this, though the magnitude of the 6z ECMWF was a little surprising. I don't expect that degree of RI. But I do think Delta will make a run at Cat 4 even if it may max out as an upper Cat 3. It's going to be a large hurricane regardless.

I don't really see any rapid deepening until tomorrow afternoon when the large core is over the best heat content and best upper tropospheric dynamics.

[emoji2957]

Really? That dude is salivating for GOM Cat 5 more than anyone here. The reality is it will just become a formidable major hurricane again. Not wishcasting, just based on environmental influences here. This is really just dumb. GOL is a good poster.

The preceding shear isn't really going to matter much now. It's essentially size of core and how much time it will have before concentric banding could hypothetically take over. Based on that MW scan, it looks prime for RI.