ATL: MICHAEL - Post-Tropical - Discussion

[northjaxpro]

It looks like Michael is definitely in the process building an impressive CDO just south of the western tip of Cuba. He is looking more impressive with time no doubt.

[MississippiWx]

Pressure has dropped some more, but the center is on the very western edge of the convection. Only gradual intensification can occur with this type of organization. Shear should begin to decrease through the day tomorrow.

[Dean4Storms]

It’s still struggling with westerly shear, let’s hope it keeps shearing the crap out of this thing!

[Aric Dunn]

we might have an odd ball hurricane. those rare half semi-circle eyewall systems under shear.

[northjaxpro]

Shear I believe is already beginning to drop. Convection is already beginning to expand to the west side of center..

[Aric Dunn]

:uarrow: Shear I believe is already beginning to drop Convection is already beginning to expand to the west side of center.

yeah shear is for sure dropping that is pretty evident.

[MississippiWx]

The wind field has certainly expanded and increased in strength in the NW quad.

[chaser1]

Ozonepete, your thoughts about Michael? Looks lije I am going to have to get things around the yard secured and done today.

If the 00Z runs don't shift eastward and recon doesn't find it further east you guys in Jax can rest a little more easily because it would be passing further west. But there's no way of knowing yet. Pay it safe!

Flip side argument to that however might be how delayed will Michael be toward reaching NHC 12Z and 0Z forecast points tomorrow (and tomm. eve)? That net difference in time might result in latter track orientation that carries Michael more ENE prior to landfall. Additionally, I also believe that with time, the steering flow might slacken just a little

[Shell Mound]

Clearly the 00Z HWRF is utilising bad physics. It depicts rapid deepening (to major-hurricane status) within the next day, despite unfavourable northwesterly shear. The bursting, displaced convective pattern on the run would support modest intensification to a low-end hurricane within twenty-four hours, not rapid intensification to Cat-3 status. Most of the dynamical models, including the GFS and ECMWF, are showing unrealistically fast intensification over the next few days. Only the FV3-GFS is somewhat reasonable. Note that even the most aggressive intensity forecasts show the most significant deepening a day before landfall, as the system begins to feel the impact of a poleward outflow jet in advance of the mid-level trough. A disorganised system in the short term means less pre-landfall intensification by the time conditions improve somewhat, owing to the absence of a well-stacked inner core prior to the onset of that "sweet zone" for intensification. I actually think that the NHC's intensity forecast may be too high and that a moderate to strong Cat-1 hurricane (at peak) is most probable, followed by some pre-landfall weakening due to dry continental air and shallower shelf waters near the shoreline. This system looks to be similar to last year's Nate in terms of evolution. Landfall will likely be east of most of the guidance, with significant rainfall over the FL peninsula. I would not be shocked to see a landfall between Apalachicola and St. Marks, FL, as a sprawling, high-end tropical storm or low-end Cat-1 hurricane, with widespread but not extreme surge, locally heavy rainfall, and a risk for tornadoes.

[xironman]

55kt flight level winds 125 miles SE of the center, continue to be impressed by the size of the wind field for this early in the game

[Aric Dunn]

Clearly the 00Z HWRF is utilising bad physics. It depicts rapid deepening (to major-hurricane status) within the next day, despite unfavourable northwesterly shear. The bursting, displaced convective pattern on the run would support modest intensification to a low-end hurricane within twenty-four hours, not rapid intensification to Cat-3 status. Most of the dynamical models, including the GFS and ECMWF, are showing unrealistically fast intensification over the next few days. Only the FV3-GFS is somewhat reasonable. Note that even the most aggressive intensity forecasts show the most significant deepening a day before landfall, as the system begins to feel the impact of a poleward outflow jet in advance of the mid-level trough. A disorganised system in the short term means less pre-landfall intensification by the time conditions improve somewhat, owing to the absence of a well-stacked inner core prior to the onset of that "sweet zone" for intensification. I actually think that the NHC's intensity forecast may be too high and that a moderate to strong Cat-1 hurricane (at peak) is most probable, followed by some pre-landfall weakening due to dry continental air and shallower shelf waters near the shoreline. This system looks to be similar to last year's Nate in terms of evolution. Landfall will likely be east of most of the guidance, with significant rainfall over the FL peninsula. I would not be shocked to see a landfall between Apalachicola and St. Marks, FL, as a sprawling, high-end tropical storm or low-end Cat-1 hurricane, with widespread but not extreme surge, locally heavy rainfall, and a risk for tornadoes.

ok so all the models are somehow magically using the wrong physics... even though the equations have not changed.

you are going against every last thing that we have at our disposal that has served us well over the last 20 plus years...despite the rare occasion.

shelf waters will play no role in weakening with a moving tropical cyclone going over 83 to 85 degree water...

if your going to say everything is wrong including the NHC. you better provide some actual proof....

[AutoPenalti]

Clearly the 00Z HWRF is utilising bad physics. It depicts rapid deepening (to major-hurricane status) within the next day, despite unfavourable northwesterly shear. The bursting, displaced convective pattern on the run would support modest intensification to a low-end hurricane within twenty-four hours, not rapid intensification to Cat-3 status. Most of the dynamical models, including the GFS and ECMWF, are showing unrealistically fast intensification over the next few days. Only the FV3-GFS is somewhat reasonable. Note that even the most aggressive intensity forecasts show the most significant deepening a day before landfall, as the system begins to feel the impact of a poleward outflow jet in advance of the mid-level trough. A disorganised system in the short term means less pre-landfall intensification by the time conditions improve somewhat, owing to the absence of a well-stacked inner core prior to the onset of that "sweet zone" for intensification. I actually think that the NHC's intensity forecast may be too high and that a moderate to strong Cat-1 hurricane (at peak) is most probable, followed by some pre-landfall weakening due to dry continental air and shallower shelf waters near the shoreline. This system looks to be similar to last year's Nate in terms of evolution. Landfall will likely be east of most of the guidance, with significant rainfall over the FL peninsula. I would not be shocked to see a landfall between Apalachicola and St. Marks, FL, as a sprawling, high-end tropical storm or low-end Cat-1 hurricane, with widespread but not extreme surge, locally heavy rainfall, and a risk for tornadoes.

Tell that to the Euro.

[canefan]

Re: Shell Mound:

What a reckless post. This could be worse than Opal for the FL Panhandle, and you forecast a weekend play date in the Walmart portable pool? Unrealistic intensification???? You know more than 90% of the world's top models? I pray you are correct, but this is obviously a situation that warrants major concern and significant efforts to protect life and loss.

[NDG]

Recon just found 68 knots flight level winds.

[Shell Mound]

Clearly the 00Z HWRF is utilising bad physics. It depicts rapid deepening (to major-hurricane status) within the next day, despite unfavourable northwesterly shear. The bursting, displaced convective pattern on the run would support modest intensification to a low-end hurricane within twenty-four hours, not rapid intensification to Cat-3 status. Most of the dynamical models, including the GFS and ECMWF, are showing unrealistically fast intensification over the next few days. Only the FV3-GFS is somewhat reasonable. Note that even the most aggressive intensity forecasts show the most significant deepening a day before landfall, as the system begins to feel the impact of a poleward outflow jet in advance of the mid-level trough. A disorganised system in the short term means less pre-landfall intensification by the time conditions improve somewhat, owing to the absence of a well-stacked inner core prior to the onset of that "sweet zone" for intensification. I actually think that the NHC's intensity forecast may be too high and that a moderate to strong Cat-1 hurricane (at peak) is most probable, followed by some pre-landfall weakening due to dry continental air and shallower shelf waters near the shoreline. This system looks to be similar to last year's Nate in terms of evolution. Landfall will likely be east of most of the guidance, with significant rainfall over the FL peninsula. I would not be shocked to see a landfall between Apalachicola and St. Marks, FL, as a sprawling, high-end tropical storm or low-end Cat-1 hurricane, with widespread but not extreme surge, locally heavy rainfall, and a risk for tornadoes.

ok so all the models are somehow magically using the wrong physics... even though the equations have not changed.

you are going against every last thing that we have at our disposal that has served us well over the last 20 plus years...despite the rare occasion.

shelf waters will play no role in weakening with a moving tropical cyclone going over 83 to 85 degree water...

if your going to say everything is wrong including the NHC. you better provide some actual proof....

I prefer to look at real-time conditions rather than models, especially in the short term, and to compare (current, unfolding) observations and (model) forecasts, including verification. The 00Z HWRF convective fields show lopsided, bursting thunderstorm activity until about a day before landfall. You can see the "pulsing" pattern, frame by frame, over time. This kind of evolution does favour intensification, but gradual rather than exponential. Yet the HWRF pressure fields show much more rapid near-term deepening than the convective fields (based on large-scale environmental shear) would suggest. Currently, Michael is a disorganised system. Reconnaissance data confirm that the pressure has only dropped slightly since the last pass. The dynamical models suggest that the most rapid intensification may occur within a day of landfall, as northwesterly shear diminishes and a poleward, pre-frontal outflow channel expands. Until then, the shear fields on the models indicate that the system will struggle to achieve more than slow but steady intensification. The current convective pattern is consistent with a highly sheared, broad tropical storm of moderate intensity. A broad core and wind field suggest that Michael will struggle to intensify significantly, even as environmental conditions improve just before landfall.

What a reckless post. This could be worse than Opal for the FL Panhandle, and you forecast a weekend play date in the Walmart portable pool? Unrealistic intensification???? You know more than 90% of the world's top models? I pray you are correct, but this is obviously a situation that warrants major concern and significant efforts to protect life and loss.

I never made the bold statement. People should be ready for anything, anytime, anywhere. And we all know models have weaknesses as well as strengths.

[Aric Dunn]

REcon also found what looks like another circ way deep into the convection.. the winds veered and dropped looks like something is there...

also a secondary pressure drop..

[northjaxpro]

Recon just found 68 knots flight level winds.

Yes indeed. Michael definitely ramping up now. Not good at all.

[AutoPenalti]

REcon also found what looks like another circ way deep into the convection.. the winds veered and dropped looks like something is there...

also a secondary pressure drop..

Recon found another center further east?

[Aric Dunn]

REcon also found what looks like another circ way deep into the convection.. the winds veered and dropped looks like something is there...

also a secondary pressure drop..

Recon found another center further east?

appears so. they missed it just barely but from the wind field and pressure drop. most likely yes..

[AutoPenalti]

That’s pretty interesting, if anything that may explain the east shift from the Euro