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2020 Atlantic Hurricane Season


Windspeed
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How will the current SAL outbreak influence this otherwise favorable period? Is it expected to subside soon?
Plumes of SAL dry airmass and aerosols riding the easterly jet should suppress activity for a few weeks at least. It will moderate with time as the ITCZ and individual waves begin to gain some latitude July-August.
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6 minutes ago, Windspeed said:
5 hours ago, WhiteoutWX said:
How will the current SAL outbreak influence this otherwise favorable period? Is it expected to subside soon?

Plumes of SAL dry airmass and aerosols riding the easterly jet should suppress activity for a few weeks at least. It will moderate with time as the ITCZ and individual waves begin to gain some latitude July-August.

I guess I meant more specifically, how will the upcoming favorable MJO wave influence the SAL. Would the strong SAL we have seen this week be more likely to subside during this period? I’m not familiar with how all this things interact.

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I guess I meant more specifically, how will the upcoming favorable MJO wave influence the SAL. Would the strong SAL we have seen this week be more likely to subside during this period? I’m not familiar with how all this things interact.
If SAL plumes continue to be lifted and break away into the easterly jet during the potential favorable MJO phase over the Atlantic, I am sure it would still have a negative effect on environmental conditions for cyclogenesis. But we have seen cyclogenesis occur with waves that were interacting with SAL in the past. It really just depends on location of a hypothetical wave axis versus the most hostile dry airmass and propagation of moisture flux out of the ITCZ. That's a remains to be seen kind of thing. Who knows...
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La Nina going in the Pacific subsurface.. I found a correlation of hurricane season subsurface vs surface 0.97 to 0.83 vs the 0.97 to 0.90. So it's a La Nina... but no severe wx season really, and a lot of blandness right now in the atmosphere will probably keep us away from Cat 4s or 5s. 

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4 hours ago, StormchaserChuck! said:

La Nina going in the Pacific subsurface.. I found a correlation of hurricane season subsurface vs surface 0.97 to 0.83 vs the 0.97 to 0.90. So it's a La Nina... but no severe wx season really, and a lot of blandness right now in the atmosphere will probably keep us away from Cat 4s or 5s. 

I guess I don't understand how Severe weather translates to no Cat 4's or 5's. If you have any evidence I would like to hear it, otherwise it seems unwise to say that.

Also are you forgetting we have had some pretty significant events, such as the huge event in April - the 12th I believe. It doesn't seem to be a quiet year, YTD we have had 10,861 severe weather reports.

svr.PNG

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12 hours ago, StormchaserChuck! said:

La Nina going in the Pacific subsurface.. I found a correlation of hurricane season subsurface vs surface 0.97 to 0.83 vs the 0.97 to 0.90. So it's a La Nina... but no severe wx season really, and a lot of blandness right now in the atmosphere will probably keep us away from Cat 4s or 5s. 

Lol, wut?

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8 hours ago, Windspeed said:

 

What does that show? The azores high seems to keep anything in the MDR on a due west track until the western Caribbean. But, it is still too early for much in that region base don climatology. This would be great in Aug/Sept. Unless there is something I am missing. Such as the area of lower pressures moving west. Not sure if that is pointing out development potential.

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What does that show? The azores high seems to keep anything in the MDR on a due west track until the western Caribbean. But, it is still too early for much in that region base don climatology. This would be great in Aug/Sept. Unless there is something I am missing. Such as the area of lower pressures moving west. Not sure if that is pointing out development potential.

That particular model animation shows Azore's ridging below the 700 hPa layer of the atmosphere backing down over the eastern subtropical Atlantic. Surface-to-mid level pressures weaken slightly, retreating poleward. This eases low-level easterlies off Africa, which, in turn, limits SAL propagation westward off Africa. Additionally the ITCZ would become less suppressed south and gain some latitude within that pressure regime. This would help increase instability along the MDR, with better low-level convergence for convection, especially if the MJO is in a favorable phase aloft. Tropical wave tracks would also gain some latitude with the decrease in pressure heights, and be able to tap into moisture feed from the ITCZ.

 

 

We generally see this pattern of strong Azores ridging back down in August, not early July. Typically a beefy late Spring to middle Summer eastern Atlantic Azores ridge is why we generally see SAL and too amped a low-level easterly jet to favor any MDR development. That, and upper level shear and vorticity is not yet favorable. At any rate, the pattern in the animation above may coincide with a favorable MJO [see below] and a relaxation of upper level wind shear across the Caribbean and lower MDR as well. 44da54f287ccfb1bb24ba08fe3a07146.jpg&key=c3d46da7c848de703330f30a437cf778a6f95f2f2a789f7fafd73ab0ff5bc06a7c53dc374add7ad5369d8f64b77cc2eb.jpg&key=5169f1b149672cc48fc73b2b2b3a2326b7de87f4be39cdf5511e74811456f26149a3566a09627574a8f8326c6522b170.jpg&key=debedfa44a8b70bfc2f4855646b4260c605546624a16b095c74ef90a16400718

 

 

 

 

 

 

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12 hours ago, Windspeed said:

That particular model animation shows Azore's ridging below the 700 hPa layer of the atmosphere backing down over the eastern subtropical Atlantic. Surface-to-mid level pressures weaken slightly, retreating poleward. This eases low-level easterlies off Africa, which, in turn, limits SAL propagation westward off Africa. Additionally the ITCZ would become less suppressed south and gain some latitude within that pressure regime. This would help increase instability along the MDR, with better low-level convergence for convection, especially if the MJO is in a favorable phase aloft. Tropical wave tracks would also gain some latitude with the decrease in pressure heights, and be able to tap into moisture feed from the ITCZ.

 

 

We generally see this pattern of strong Azores ridging back down in August, not early July. Typically a beefy late Spring to middle Summer eastern Atlantic Azores ridge is why we generally see SAL and too amped a low-level easterly jet to favor any MDR development. That, and upper level shear and vorticity is not yet favorable. At any rate, the pattern in the animation above may coincide with a favorable MJO [see below] and a relaxation of upper level wind shear across the Caribbean and lower MDR as well. 44da54f287ccfb1bb24ba08fe3a07146.jpg&key=c3d46da7c848de703330f30a437cf778a6f95f2f2a789f7fafd73ab0ff5bc06a7c53dc374add7ad5369d8f64b77cc2eb.jpg&key=5169f1b149672cc48fc73b2b2b3a2326b7de87f4be39cdf5511e74811456f26149a3566a09627574a8f8326c6522b170.jpg&key=debedfa44a8b70bfc2f4855646b4260c605546624a16b095c74ef90a16400718

 

 

 

 

 

 

Wow, you are a wealth of information! Thanks!

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13 hours ago, CheeselandSkies said:

Among other things, it makes it darn near impossible to retire any name earlier than "F." Even in 1992, Andrew probably wouldn't have been Andrew if names were burned through like they are now.

Well we did have a catastrophic D storm just last year. NHC definitely got a little generous with some storms though.

At the very least we have ACE which isn’t significantly skewed by these blink storms. 

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On 6/23/2020 at 10:16 PM, CheeselandSkies said:

Among other things, it makes it darn near impossible to retire any name earlier than "F." Even in 1992, Andrew probably wouldn't have been Andrew if names were burned through like they are now.

If it meets the criteria then it should get a name. Dolly definitely met the criteria for a TS. 

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The latest 2 runs (maybe more) of the GFS shows an area of low pressure with a wave in the monsoon trough dropping down to 997mb as it moves WNW over Trinidad and just off the coast of Venezuela around 260 hours out.

Does anyone have thoughts on this? It is in fantasy land but very interesting to see a low latitude spin up early in the season just like @Windspeed forecasted.

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Fairly healthy wave axis with an MCS mid-level vort max south of the Verdes. Who knows if it will persist long with the SAL locked in to its NW. But interesting nonetheless. 12Z ECMWF does have a solution or two that closes off a surface low but there's negligible model support beyond that.a8a4fe7f78857b375370977ed7b9c448.gif

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Looks like the next system could be the little end of the front hanging and developing off the coast of Georgia this weekend. Probably minor impacts for the Florida/Georgia coast then the bigger stuff stays out to sea. GFS shows maybe a hurricane OTS.

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