ATL: MICHAEL - Post-Tropical - Discussion

[GCANE]

Just checked the GOM.
CAPE is running about 2500 max.
Not forecast to be much higher on Michael's approach to landfall.
That and some possible mid-level dry air on the west flank will be the only two inhibiting factors I see.
Sorry to say, but there are a lot more conducive factors for intensification.

[GBPackMan]

I'am with GBPackMan here by no means the gulf looks ideal for RI. Inhibiting factors such as strong winds aloft from the west, along with dry air ingestion, are going to likely keep the system tilted with height. I just don't see a prime setup where you should seek explosive development.

I see absolutely no sign of westward shear or midlevel shear on satellite right now

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

That is because you're looking at close range imagery with little mid or high level clouds to follow aside from the ones within the storm itself, although if you look at the western edge clouds north of the Yucatan in the vicinity of 24N 88W down to 22N 89W, you can see the lower level outflowing clouds moving west yet the top level clouds being pushed east. Look at the loops over the entire gulf. Storms flaring up just offshore from TX where the tops suddenly get pulled into the gulf eastward due to shear. Storms flaring up along southeastern MX with the tops being sheared off pushing NE.
You can also see the drier air coming off the Yucatan land starting to get wrapped into the circulation. The internal intensification may limit this some but it may also wrap its way in causing the eye wall to partially collapse again.

[yzerfan]

Most of the panhandle is sandy ground with fairly heavy pine tree forests and plenty of uninhabited swamp areas which is natures way of handling water overflow. We can get 2-4" of rain within 1-2 hours and things could be dry 2 hours later. This sand is able to handle this amount of water much better than the clay or dirt soils further inland.

Our house is on very sandy soil and 45 feet above sea level. The worst rainstorm we've gotten was 24 inches in 36 hours from a springtime stalled front, and we just got a rather soggy front yard from it.

I did the water and peanut butted sandwich fixings run earlier (the local Publix was polite chaos) and got one of the cars fully fueled. Spousal Unit will hopefully be able to take care of his car on the way home. Garage door and windows are Miami-Dade rated and we had the roof replaced in July so will probably hunker down and hide from the wind.

[Hammy]

I'm thinking part of the inner cores problem is it's being disrupted by western Cuba, especially because of its size. I think it's presentation will improve once it gets away from Cuba.

Ps. For those saying no effect, not sure I agree, especially on a weak formative eyewall, i bet it looks a world better in 12hrs...

I'm wondering if there's also some dry air coming in from the Yucatan which could let up once it exits the Caribbean.

[robbielyn]

Michael looks like the shape of a football standing up. also being flatten on the west side. what's up with that?

[Aric Dunn]

it is about to explode.. some inner core convection starting to show up inside that large leader burst.

[ozonepete]

The 3 most trusted intensity models based on the 12z Oct 8 runs paint this as a mid to strong Cat1 (80-90 mph), with lower potential of weak Cat 2 at or close to landfall (90-100mph). There is better potential of intensifying to Cat 2 within 24-36 hours before landfall, but dropping back off to Cat 1 as it gets closer to land. Nowhere close to Cat 3-4 Opal.

I don't mind you giving an opinion, but can you really back up this statement? HWRF is one of the few models to show consistent intensity skill at 3 days. The NHC goes over these stats every year, you can find them on their web page.

That's 110kts at landfall. Can you identify the other models you used?

https://imgur.com/ENW4YVt


Some models do well at path, not so much at directional speed or intensity, some do well with intensity but not so much the path or speed, etc. HWRF is one that has done well with intensity, but not so well with path or movement speed. This is where GFS and the Euro model have fared better the last few years.
So looking at the models that have a fairly consistent past accuracy with intensity, points to a high likelihood of a strong Cat 1 being the most likely scenario, with possible bump into Cat 2 before dropping off 12-18h before landfall. Almost all of them show the intensity either leveling or dropping off from 36-48h (from 12z Oct 8 model runs). The 18z should be coming out soon so this may change.

Still, with the cooler night time autumn air over the southeastern US, plus the cooler outflow from the jet stream with the southern point slowly adjusting NNE getting drawn into the storm around 24h before landfall, this points to a decent weakening. This is why I believe a weak Cat 2, then approx 24h before landfall the cooler drier air being drawn in weakening it to 80-90mph max winds within a narrow area of the eye.

Thanks for the supporting image and text on intensity. The 2 things I don't see:

1. "the cooler night time autumn air over the southeastern US". There is now, and still will be, high theta-e and high dewpoint air over the entire area on Wednesday morning at landfall. The front will still be too far west to cause any entrainment of cooler air at that time. No forecasts show that happening before landfall.

2. "the cooler outflow from the jet stream with the southern point slowly adjusting NNE getting drawn into the storm around 24h before landfall" . Air at jet stream level does not get drawn into the circulation of a TC. Air at jet level steers and affects upper level outflow to help or hinder intensity. It's temperature doesn't matter for the mid or lower levels. As the jet approaches in these cases it often actually improve upper level outflow by evacuating air from over the top of the TC.

[gatorcane]

Wow look at that convection building near the eye, this has soon-to-be-major written all over it

https://www.tropicaltidbits.com/sat/sat ... t=vis-swir

[GBPackMan]

Very rapid warming of the eye from those two towers.
Just brushing the tip of Cuba.
Will likely not even phase it.


http://i67.tinypic.com/35chok1.jpg

flat like florida, zero effect on inflow and off to the gulf

May be true about the rest of Florida, but the panhandle has the highest point in the state (a whopping 345ft ASL) which is less than an hours drive from the coast (approx 45-50 miles). Where the storm surge may have a greater impact on the rest of the state, the western panhandle has a much greater elevation increase meaning much less land area affected. Granted the big bend area is primarily uninhabited swamp land, the coastal towns will still likely see water a foot or two deep throughout most of town.

[NDG]

The eye can be clearly seen as it clips the western of Cuba.

[xironman]

I'm thinking part of the inner cores problem is it's being disrupted by western Cuba, especially because of its size. I think it's presentation will improve once it gets away from Cuba.

Ps. For those saying no effect, not sure I agree, especially on a weak formative eyewall, i bet it looks a world better in 12hrs...

I'm wondering if there's also some dry air coming in from the Yucatan which could let up once it exits the Caribbean.

There does not seem to be a huge amount of shear to push that air in from the Yucatan into the storms envelope.

[artist]

Very rapid warming of the eye from those two towers.
Just brushing the tip of Cuba.
Will likely not even phase it.


http://i67.tinypic.com/35chok1.jpg

flat like florida, zero effect on inflow and off to the gulf

May be true about the rest of Florida, but the panhandle has the highest point in the state (a whopping 345ft ASL) which is less than an hours drive from the coast (approx 45-50 miles). Where the storm surge may have a greater impact on the rest of the state, the western panhandle has a much greater elevation increase meaning much less land area affected. Granted the big bend area is primarily uninhabited swamp land, the coastal towns will still likely see water a foot or two deep throughout most of town.

So, you are discounting the NWS products showing surge of up to 12 feet in some areas?
For: Coastal Wakulla County

...HURRICANE WATCH REMAINS IN EFFECT...
...STORM SURGE WATCH REMAINS IN EFFECT...

* LOCATIONS AFFECTED
- Saint Marks
- Panacea

* STORM SURGE
- LATEST LOCAL FORECAST: Life-threatening and
historic storm surge possible
- Peak Storm Surge Inundation: The potential for
8-12 feet above ground somewhere within surge prone
areas
- Window of concern: Begins Tuesday morning

- Emergency plans should include a reasonable threat
as depicted on the left.

[KWT]

it is about to explode.. some inner core convection starting to show up inside that large leader burst.

Yeah it's looking good st the moment, maybe this will be the burst that will sustain and tighten the core and eyewall.

[supercane4867]

18z best track up to 70kt

[Evil Jeremy]

The eye can be clearly seen as it clips the western of Cuba.

https://i.imgur.com/2TRFhNC.gif

I think the LLC is just above top of your circle... looks like you can see it rolling up under those northern hot towers in those last five frames.

[txwatcher91]

I'am with GBPackMan here by no means the gulf looks ideal for RI. Inhibiting factors such as strong winds aloft from the west, along with dry air ingestion, are going to likely keep the system tilted with height. I just don't see a prime setup where you should seek explosive development.

I see absolutely no sign of westward shear or midlevel shear on satellite right now

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

That is because you're looking at close range imagery with little mid or high level clouds to follow aside from the ones within the storm itself, although if you look at the western edge clouds north of the Yucatan in the vicinity of 24N 88W down to 22N 89W, you can see the lower level outflowing clouds moving west yet the top level clouds being pushed east. Look at the loops over the entire gulf. Storms flaring up just offshore from TX where the tops suddenly get pulled into the gulf eastward due to shear. Storms flaring up along southeastern MX with the tops being sheared off pushing NE.
You can also see the drier air coming off the Yucatan land starting to get wrapped into the circulation. The internal intensification may limit this some but it may also wrap its way in causing the eye wall to partially collapse again.

An anti-cyclone is now positioned over Michael which will help reduce any shear. Yes there is shear in southeastern MX and Texas as analyzed in the map linked below. The shear over Michael at this time is low due to this anti-cyclone that has built overhead. The GFS and other models move this anti-cyclone in tandem with Michael and as long as that happens the shear over Michael will remain low and allow for additional strengthening.
http://tropic.ssec.wisc.edu/real-time/a ... wg8shr.GIF

[OuterBanker]

Wxman. I haven't seen it mentioned yet but will that ull north of the Bahamas extending to north of PR get entrained with Michael and the front.

[SunnyThoughts]

Rick Scott live presser on TWC

[ScottNAtlanta]

I'am with GBPackMan here by no means the gulf looks ideal for RI. Inhibiting factors such as strong winds aloft from the west, along with dry air ingestion, are going to likely keep the system tilted with height. I just don't see a prime setup where you should seek explosive development.

I see absolutely no sign of westward shear or midlevel shear on satellite right now

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

That is because you're looking at close range imagery with little mid or high level clouds to follow aside from the ones within the storm itself, although if you look at the western edge clouds north of the Yucatan in the vicinity of 24N 88W down to 22N 89W, you can see the lower level outflowing clouds moving west yet the top level clouds being pushed east. Look at the loops over the entire gulf. Storms flaring up just offshore from TX where the tops suddenly get pulled into the gulf eastward due to shear. Storms flaring up along southeastern MX with the tops being sheared off pushing NE.
You can also see the drier air coming off the Yucatan land starting to get wrapped into the circulation. The internal intensification may limit this some but it may also wrap its way in causing the eye wall to partially collapse again.

That is assuming the atmosphere is static. What is there now most likely will not be there when Michael, and the environment it is creating push into it. Plus the ULL that was causing the shear is rapidly moving northward.

[KWT]

18z best track up to 70kt

Fully expected that given the flight level winds found last mission were suggestive to f 70kts. Interesting to watch the inner core dynamics right now.