ATL: HERMINE - Post-Tropical - Discussion

[Hurricane Andrew]

Could the LLC be having a fujiwara reaction with the MLC? The darn tng is moving SW, even as the MLC stays where it is.

This storm makes no sense. 09L.exe has crashed.

[SunnyThoughts]

Depression 09L

UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 AUG 2016 Time : 214500 UTC
Lat : 24:25:48 N Lon : 87:20:20 W


CI# /Pressure/ Vmax
3.3 / 992.8mb/ 51.0kt


Final T# Adj T# Raw T#
3.3 3.6 3.7

[Michele B]

the wind over in the far east quad are not flowing inward. they should s to se but rather they are S to SW. very odd.

This is probably going to degenerate into a trough as the models a few days ago showed, and that indicates that process is beginning--there's essentially little to no convergence going on by the looks of it. I still don't think this will ever get any stronger and there's nothing out there, aside from model speculation, that gives any indication otherwise.

Weird times we live in when every model calling for intensification counts as "nothing". Then again, I guess it depends who you ask.

I'll bet several fake dollars this gets named .

I think so, too and I have a theory as to why!

I believe they HAVE to name as many as possible, in order to meet their "projected" number of storms they said there would be during a particular year.

Almost a self-fulfilling prophecy type of thing.

[SouthDadeFish]

Could the LLC be having a fujiwara reaction with the MLC? The darn tng is moving SW, even as the MLC stays where it is.

This storm makes no sense. 09L.exe has crashed.

It highly likely is. A local vorticity maximum exists in three dimensions. As you move away from the vorticity maximum, the cyclonic circulation around it decreases. However, the low-level circulation is within range to "feel" the cyclonic flow around and below the mid-level circulation. The rate of rotation around the mid-level circulation depends on the strength of the vortex and how close they are to one another. Conversely, the low-level circulation is acting to rotate the mid-level circulation around cyclonically as well. You must also consider both of these vortices are embedded in a background flow, causing their cyclonic rotation around one another to be less clear. It is a complicated process, but I hope this explanation helps.

[Soonercane]

convection needs to stop wrapping around the MLC in order for it to die. It's forming a rainband around the MLC

This is why I disagree with a Hurricane Watch. I thought a TS watch was enough for now

Is this acting similarly to Gabrielle in 2013 when it was over Puerto Rico with the MLC actually pulling energy away from the LLC?

Good analogy, I do think it will get named but I would bet it doesn't get over 45 knots

[TJRE]

Nasty view as the sun goes down

LOOP
http://climate.cod.edu/hanis/satellite/ ... o-vis-1-24

http://climate.cod.edu/hanis/satellite/ ... verDim=100

[Hurricane Andrew]

Could the LLC be having a fujiwara reaction with the MLC? The darn tng is moving SW, even as the MLC stays where it is.

This storm makes no sense. 09L.exe has crashed.

It highly likely is. A local vorticity maximum exists in three dimensions. As you move away from the vorticity maximum, the cyclonic circulation around it decreases. However, the low-level circulation is within range to "feel" the cyclonic flow around and below the mid-level circulation. The rate of rotation around the mid-level circulation depends on the strength of the vortex and how close they are to one another. Conversely, the low-level circulation is acting to rotate the mid-level circulation around cyclonically as well. You must also consider both of these vortices are embedded in a background flow, causing their cyclonic rotation around one another to be less clear. It is a complicated process, but I hope this explanation helps.

It does, thank you. It makes a lot of sense actually. Considering that the LLC has been moving while the MLC stays stationary, this is definately a lopsided reaction. The blossoming convection is about to cover both. The whole thing might pull together, but it has limited time to do so IMO.

[robbielyn]

convection needs to stop wrapping around the MLC in order for it to die. It's forming a rainband around the MLC

This is why I disagree with a Hurricane Watch. I thought a TS watch was enough for now

Amen! this was issued 48 hours out plenty of time to evacuate so a TS watch til tomorrow would have been fine I think also.

[drewschmaltz]

convection needs to stop wrapping around the MLC in order for it to die. It's forming a rainband around the MLC

This is why I disagree with a Hurricane Watch. I thought a TS watch was enough for now

Is this acting similarly to Gabrielle in 2013 when it was over Puerto Rico with the MLC actually pulling energy away from the LLC?

Good analogy, I do think it will get named but I would bet it doesn't get over 45 knots

NHC, forum mets, and models say otherwise. I will take that bet and say 50knots inside 18 hours.

[GCANE]

The ULL north of Hispaniola is just about to grab the outflow of TD9 and ventilate it with a second outflow channel.

http://tropic.ssec.wisc.edu/real-time/a ... g8wvir.GIF

[AutoPenalti]

Nasty view as the sun goes down

LOOP
http://climate.cod.edu/hanis/satellite/ ... o-vis-1-24

http://climate.cod.edu/hanis/satellite/ ... verDim=100

WARNING: That picture is NSFW.

[SouthDadeFish]

Something to keep in mind about the mid-level centers... They are typically generated from prior convection. The exposed mid-level center off to the SE everyone is observing now was created by the last night's convective burst. As the convection faded, the vorticity remains, and will do so until it is mixed out. This new convective burst has the potential to create a new mid-level circulation if it persists. It is the nature of convection and latent heat release. It generates vorticity.

If the new convective burst can remain aligned with the low-level center (something that hasn't happened thus far), then mid-level vorticity will be generated over the LLC. For the most part, the current convective burst has been aligned with the LLC. This will be something to keep an eye on in the overnight hours. If convection remains aligned with the LLC, this will help to vertically stack the TC.

[TropicalAnalystwx13]

the wind over in the far east quad are not flowing inward. they should s to se but rather they are S to SW. very odd.

This is probably going to degenerate into a trough as the models a few days ago showed, and that indicates that process is beginning--there's essentially little to no convergence going on by the looks of it. I still don't think this will ever get any stronger and there's nothing out there, aside from model speculation, that gives any indication otherwise.

The National Hurricane Center would not have hurricane watches up and be forecasting a strong tropical storm landfall if there weren't indications otherwise. They know what they're doing.

Nine is organizing this evening. The LLC and MLC are as close as they've ever been, pressures are slowly falling, and convection continues to build.

[Blinhart]

Where is this big turn to North that is suppose to be happening?

Edit: On a side note the Mid Level winds are blowing NNW here in South Louisiana.

[chaser1]

Something to keep in mind about the mid-level centers... They are typically generated from prior convection. The exposed mid-level center off to the SE everyone is observing now was created by the last night's convective burst. As the convection faded, the vorticity remains, and will do so until it is mixed out. This new convective burst has the potential to create a new mid-level circulation if it persists. It is the nature of convection and latent heat release. It generates vorticity.

If the new convective burst can remain aligned with the low-level center (something that hasn't happened thus far), then mid-level vorticity will be generated over the LLC. For the most part, the current convective burst has been aligned with the LLC. This will be something to keep an eye on in the overnight hours. If convection remains aligned with the LLC, this will help to vertically stack the TC.

... and in essence likely pull the old MLC, BUT might that feature potentially be fully absorbed or potentially rotate around any vertically stacked core as a "vorticity max" type feature?

[hohnywx]

convection needs to stop wrapping around the MLC in order for it to die. It's forming a rainband around the MLC

This is why I disagree with a Hurricane Watch. I thought a TS watch was enough for now

Amen! this was issued 48 hours out plenty of time to evacuate so a TS watch til tomorrow would have been fine I think also.

What? The NHC rules state that a watch is issued 48 hours in advance of either TS or Hurricane conditions. We are less than 48 hours away from conditions potentially arriving at the Florida coast.

[TropicalAnalystwx13]

Where is this big turn to North that is suppose to be happening?

Edit: On a side note the Mid Level winds are blowing NNW here in South Louisiana.

It's already beginning a northwest motion. It should turn north overnight and northeast by tomorrow evening.

[chaser1]

I was under the impression that only 36 hr.s were required in advance of T.S. force conditions, but 48 hr. for hurricane force.

[Blinhart]

Where is this big turn to North that is suppose to be happening?

Edit: On a side note the Mid Level winds are blowing NNW here in South Louisiana.

It's already beginning a northwest motion. It should turn north overnight and northeast by tomorrow evening.

When does the Recon get back in there to show that the center is still further South.

[SouthDadeFish]

... and in essence likely pull the old MLC, BUT might that feature potentially be fully absorbed or potentially rotate around any vertically stacked core as a "vorticity max" type feature?

The old mid-level vorticity maximum will remain present until it is either mixed out through turbulent processes and/or merged with a new mid-level center. It will likely be a gradual process.