ATL: BETA - Remnants - Discussion

[TeamPlayersBlue]

A closed circulation in the gulf with convection, not much shear.... Even with some dry air anticipated to enter the storm, I will not take any storm in the gulf for granted with these characteristics. Tonight is very important, when it comes to how the life of this storm will play out. Diurnal cycle is primetime for cyclones.

Living in Houston, my down in Galveston. Not sure what i want to see here, but im thinking a Cat 1-2 hurricane with the NHC track might be best for Houston. A messy 60 mph TS with a dirty north and eastern quadrant could be a disastrous situation for Houston.

[wxman57]

Claudette was a strengthening cat 1 at landfall I witnessed her center come right over Victoria. I don’t think this will be close to her. I’m hearing about a Don scenario???

Maybe somewhere between Claudette & Don. No "death ridge" for Beta, but there will be a good bit of dry air to its west and south. If entrained into the center, it would cause weakening. Claudette didn't have to deal with such dry air.

[wxman57]

A closed circulation in the gulf with convection, not much shear.... Even with some dry air anticipated to enter the storm, I will not take any storm in the gulf for granted with these characteristics. Tonight is very important, when it comes to how the life of this storm will play out. Diurnal cycle is primetime for cyclones.

Living in Houston, my down in Galveston. Not sure what i want to see here, but im thinking a Cat 1-2 hurricane with the NHC track might be best for Houston. A messy 60 mph TS with a dirty north and eastern quadrant could be a disastrous situation for Houston.

I'm not far from you just outside the SW corner of loop 610. I'm thinking a tad inland and 45-50 kts, at most, as it passes. Could see 10+ inches rain, MAYBE. Not sure how much rain will fall north of the track.

[jaguars_22]

Wxman what should I plan on seeing here in Victoria rain and wind?

[TeamPlayersBlue]

A closed circulation in the gulf with convection, not much shear.... Even with some dry air anticipated to enter the storm, I will not take any storm in the gulf for granted with these characteristics. Tonight is very important, when it comes to how the life of this storm will play out. Diurnal cycle is primetime for cyclones.

Living in Houston, my down in Galveston. Not sure what i want to see here, but im thinking a Cat 1-2 hurricane with the NHC track might be best for Houston. A messy 60 mph TS with a dirty north and eastern quadrant could be a disastrous situation for Houston.

I'm not far from you just outside the SW corner of loop 610. I'm thinking a tad inland and 45-50 kts, at most, as it passes. Could see 10+ inches rain, MAYBE. Not sure how much rain will fall north of the track.

Thinking 45-50 kt at landfall in Matagorda (or wherever) or you thinking 45-50 kt as it passes Houston?

Wind wise, that would be great, but i think a cat 1 would tighten the storm up some, reducing our rainfall some. Again, lots of variables, but do you expect the rain shield to stay tight with the storm or expand northward? GFS and other models show it staying tight but im not sure we can fully trust them with that.

I understand there is alot of dry air north of us, but i think it pulls away by Monday.

[PTrackerLA]

Looking better for us in Louisiana, just some heavy rain possible as of now. We don't need another storm.

[missdee33]

From Dickinson here, between Galveston and Houston one of the harder hit towns from Harvey. Keeping a close eye on this one!

[tailgater]

Looking better for us in Louisiana, just some heavy rain possible as of now. We don't need another storm.

Yeah, really hoping Beta stays away from Sw Louisiana, I drove through there a few times heading west this week. That area looks like Tarp city and tons of debris scattered everywhere. Power is still out for lots of people.

Pretty high anemometers but that is getting close to the coast
https://www.ndbc.noaa.gov/plot_wind_pres.php?station=kscf&uom=E&time_diff=-5&time_label=CDT
https://www.ndbc.noaa.gov/plot_wind_pres.php?station=lopl1&uom=E&time_diff=-5&time_label=CDT

[Stormcenter]

Way way too early to make that assumption especially
the way the models have performed this season. IMO

Looking better for us in Louisiana, just some heavy rain possible as of now. We don't need another storm.

[GCANE]

Tower appears to be washing out due to the shear.
Leaving a nice warm-core feature though.
In pulse mode now.
When the next tower fires will indicate how rapidly this may intensify.

I was under the impression that evaporation in the storm's convection results in cold pool. How does convection washing out here leave warm core features? Also can you explain how cold pool features form and what it means for convergence outside of the cold pool? I'm just now learning about these dynamics of TCs.

Yes, evaporation near the surface creates cold pool as well as strong downdrafts.
Since towers in a vertically sheared environment are tilted, the downdraft eventually cuts off the LL infeed.
The cold pool remains with horizontal wind created by the thermal gradient.
The Coriolis force on that wind creates a vorticity that drives an updraft creating new towers.
This explains the pulsing behavior.

When the shear lessens, the towers become more vertical.
As updraft moisture condenses, it releases heat in the upper troposphere creating the warm core above the cold pool.

[Aric Dunn]

This convective burst is actually quite good. it is in all quads around the center and the column up through about 400 MB is rotating.

[CrazyC83]

Given the trend of RI'ing storms up to landfall this year, I'd be paying close attention.

[GCANE]

Tower appears to be washing out due to the shear.
Leaving a nice warm-core feature though.
In pulse mode now.
When the next tower fires will indicate how rapidly this may intensify.

I was under the impression that evaporation in the storm's convection results in cold pool. How does convection washing out here leave warm core features? Also can you explain how cold pool features form and what it means for convergence outside of the cold pool? I'm just now learning about these dynamics of TCs.

Yes, evaporation near the surface creates cold pool as well as strong downdrafts.
Since towers in a vertically sheared environment are tilted, the downdraft eventually cuts off the LL infeed.
The cold pool remains with horizontal wind created by the thermal gradient.
The Coriolis force on that wind creates a vorticity that drives an updraft creating new towers.
This explains the pulsing behavior.

When the shear lessens, the towers become more vertical.
As updraft moisture condenses, it releases heat in the upper troposphere creating the warm core above the cold pool.

BTW, a clear sign that a TC is a shear-driven cold-pool system are outflow boundaries.
The infeed is taken out by the large downdraft and LL wind direction changes from going into the tower to rushing away from the tower.
The refiring process then begins anew as the cold pool and shear create updrafts to again fire towers.

[wxman57]

I am seeing what could be a significant trend in recent model runs - taking Beta right into Texas with a much-delayed northerly turn. This would increase rain somewhat along the middle TX coast, but there will be so much dry air around it, that the rain may not be too bad. Only a few inches of rain for us in Houston if that happens. Haven't adjusted our track inland and weakening to a depression yet, but that is quite possible Decreasing chances it will become a hurricane, given the current issue with dry air.

[us89]

I was under the impression that evaporation in the storm's convection results in cold pool. How does convection washing out here leave warm core features? Also can you explain how cold pool features form and what it means for convergence outside of the cold pool? I'm just now learning about these dynamics of TCs.

Yes, evaporation near the surface creates cold pool as well as strong downdrafts.
Since towers in a vertically sheared environment are tilted, the downdraft eventually cuts off the LL infeed.
The cold pool remains with horizontal wind created by the thermal gradient.
The Coriolis force on that wind creates a vorticity that drives an updraft creating new towers.
This explains the pulsing behavior.

When the shear lessens, the towers become more vertical.
As updraft moisture condenses, it releases heat in the upper troposphere creating the warm core above the cold pool.

BTW, a clear sign that a TC is a shear-driven cold-pool system are outflow boundaries.
The infeed is taken out by the large downdraft and LL wind direction changes from going into the tower to rushing away from the tower.
The refiring process then begins anew as the cold pool and shear create updrafts to again fire towers.

Interesting. Sounds fairly similar to a typical land-based MCS.

[Aric Dunn]

Given the trend of RI'ing storms up to landfall this year, I'd be paying close attention.

Agreed. given the limited dry air. and as the ridging builds in that would hault the progess of the dry air south and will begin to push it back inland.

shear axis also appears to be lifting north and all it would take is one solid large burst of convection to shift that axis farther north.

[ConvergenceZone]

I am seeing what could be a significant trend in recent model runs - taking Beta right into Texas with a much-delayed northerly turn. This would increase rain somewhat along the middle TX coast, but there will be so much dry air around it, that the rain may not be too bad. Only a few inches of rain for us in Houston if that happens. Haven't adjusted our track inland and weakening to a depression yet, but that is quite possible Decreasing chances it will become a hurricane, given the current issue with dry air.

Yep. An insane amount of dry air. This is much different setup than previous RI storms this year. Probably a mid level to high level tropical storm at landfall.

[SoupBone]

I am seeing what could be a significant trend in recent model runs - taking Beta right into Texas with a much-delayed northerly turn. This would increase rain somewhat along the middle TX coast, but there will be so much dry air around it, that the rain may not be too bad. Only a few inches of rain for us in Houston if that happens. Haven't adjusted our track inland and weakening to a depression yet, but that is quite possible Decreasing chances it will become a hurricane, given the current issue with dry air.

The HWRF has been on this path for at least two days now (I'm sure you've seen that being in your position), and the Euro also showed it last run.

[TheStormExpert]

There is ALOT of dry air around in the NW Gulf. Wouldn’t surprise me if Beta fails to become a hurricane. Also being that fronts are passing through or near the Gulf Coast this should be the last western Gulf threat of the season at least in my opinion.

[GCANE]

Yes, evaporation near the surface creates cold pool as well as strong downdrafts.
Since towers in a vertically sheared environment are tilted, the downdraft eventually cuts off the LL infeed.
The cold pool remains with horizontal wind created by the thermal gradient.
The Coriolis force on that wind creates a vorticity that drives an updraft creating new towers.
This explains the pulsing behavior.

When the shear lessens, the towers become more vertical.
As updraft moisture condenses, it releases heat in the upper troposphere creating the warm core above the cold pool.

BTW, a clear sign that a TC is a shear-driven cold-pool system are outflow boundaries.
The infeed is taken out by the large downdraft and LL wind direction changes from going into the tower to rushing away from the tower.
The refiring process then begins anew as the cold pool and shear create updrafts to again fire towers.

Interesting. Sounds fairly similar to a typical land-based MCS.

They all follow the same physics