Low Pressure in the Central Atlantic (Is Invest 91L)
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- Hurricaneman
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Re: Tropical Wave Near the Cabo Verde Islands
Iceresistance wrote:SFLcane wrote:Iceresistance wrote:This could be a problem down the road if it breaks the Monsoon Trough. (I'm saying "if" because it could get retrograded back into the larger system at the African Coast.)
Dry air (and/or SAL) is limited ahead of it.
https://s4.gifyu.com/images/g16split.jpg
https://s4.gifyu.com/images/g16split.jpg
Might be outflow already? (Look to the far right)
https://s4.gifyu.com/images/wg8wvir.gif
https://s4.gifyu.com/images/wg8wvir.gif
Impressive convection with a lot of lightning within it. (Is there a circulation with it as well?)![]()
https://s4.gifyu.com/images/53431668.gif
https://s4.gifyu.com/images/53431668.gif
Upper divergence holy cow!
I was thinking of the same thing too, this could be a troublemaker down the road if it keeps going like this. And it's basically Midnight where this system is located! The strong convection appears to be nonstop in the past few hours.
More like the last 24 hrs which really is concerning and I believe the islands need to keep tabs on this for late next week
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Re: Tropical Wave Near the Cabo Verde Islands
When is DMIN? Is it right as the sun rises, or like 3 or 4 am?
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Re: Tropical Wave Near the Cabo Verde Islands
Hurricaneman wrote:I believe the SW lobe will win out, the NE lobe is fighting dry air a I do believe SAL will get that one while the vorticity with the SW one will increase with little to no dry air to inhibit it
The NE lobe still has the strongest 850mb vorticity signature, so the SW lobe will need to maintain its exceptional convection in order to win out. There’s also some dry air just north of this lobe that might try to sneak its way in. If this looks as good tomorrow morning as it does now, then we could have something brewing.
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I am only a meteorology enthusiast who knows a decent amount about tropical cyclones. Look to the professional mets, the NHC, or your local weather office for the best information.
- skyline385
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Re: Tropical Wave Near the Cabo Verde Islands
Looking at all these weak & broad vorticity centers it is going to need a LOT of consolidating before it starts developing. One of those centers is actually the size of Florida



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- Iceresistance
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Re: Tropical Wave Near the Cabo Verde Islands
Hurricaneman wrote:Iceresistance wrote:SFLcane wrote:
Upper divergence holy cow!
I was thinking of the same thing too, this could be a troublemaker down the road if it keeps going like this. And it's basically Midnight where this system is located! The strong convection appears to be nonstop in the past few hours.
More like the last 24 hrs which really is concerning and I believe the islands need to keep tabs on this for late next week
Only if it maintains this kind of convection, which I do believe is possible since this area has been mostly untapped this year.
Also appears that the SW area is the dominating system, the NE part of the very broad disturbance is likely the sacrificial part to get the other convective area really going.
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Bill 2015 & Beta 2020
Winter 2020-2021
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Winter 2020-2021

All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
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- weeniepatrol
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Re: Tropical Wave Near the Cabo Verde Islands
IsabelaWeather wrote:When is DMIN? Is it right as the sun rises, or like 3 or 4 am?
Right as the sun sets, after the heating of the day flattening the temperature gradient between surface and upper troposphere. Right as the sun rises is DMAX from radiational cooling restrengthening the temperature gradient. Remember that convection is a function of vertical temperature difference and it takes less energy to warm / cool the upper levels than surface due to less moisture content (water vapor has a higher heat capacity and there's less of it higher up) and overall less density (pressure is lower higher up)
Last edited by weeniepatrol on Thu Aug 25, 2022 10:08 pm, edited 3 times in total.
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- InfernoFlameCat
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Re: Tropical Wave Near the Cabo Verde Islands
IsabelaWeather wrote:When is DMIN? Is it right as the sun rises, or like 3 or 4 am?
DMIN is at sunset. DMAX is at sunrise.
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Re: Tropical Wave Near the Cabo Verde Islands
I believe today's 12Z is the first UKMET run developing this in addition to it still having the other genesis it has had for a couple of days.
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Personal Forecast Disclaimer:
The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
- skyline385
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Re: Tropical Wave Near the Cabo Verde Islands
DMAX should be at night as the upper troposphere cools from a lack of solar radiation and enhances the gradient between the warm waters and cooler atmosphere. During the day, the gradient decreases as the atmosphere heats up and this results in DMIN.
If we are talking about the time of day when DMIN is at it's absolute lowest then it should be during sunset as the temperature gradient is lowest then after the sustained heating during the day.
Here is one random article I found which explains it in more detail than what I said above
https://www.carstensweather.com/post/th ... convection
If we are talking about the time of day when DMIN is at it's absolute lowest then it should be during sunset as the temperature gradient is lowest then after the sustained heating during the day.
Here is one random article I found which explains it in more detail than what I said above
https://www.carstensweather.com/post/th ... convection
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Re: Tropical Wave Near the Cabo Verde Islands
00z GFS may be correcting towards Euro's solution. 850mb vorticity similar with 18z Euro @ 00z Saturday.
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- Iceresistance
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Re: Tropical Wave Near the Cabo Verde Islands
Outflow is almost 100% complete on the convective area! 

https://s4.gifyu.com/images/wg8wvir-1.gif
Comparison from previous update

https://s4.gifyu.com/images/wg8wvir.gif
(Again, the bottom right corner is where it is)


https://s4.gifyu.com/images/wg8wvir-1.gif
Comparison from previous update

https://s4.gifyu.com/images/wg8wvir.gif
(Again, the bottom right corner is where it is)
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Bill 2015 & Beta 2020
Winter 2020-2021
All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
Winter 2020-2021

All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
- skyline385
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- skyline385
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Re: Tropical Wave Near the Cabo Verde Islands
Iceresistance wrote:Outflow is almost 100% complete on the convective area!
https://s4.gifyu.com/images/wg8wvir-1.gif
https://s4.gifyu.com/images/wg8wvir-1.gif
Comparison from previous update
https://s4.gifyu.com/images/wg8wvir.gif
https://s4.gifyu.com/images/wg8wvir.gif
(Again, the bottom right corner is where it is)
CIMSS has an East Atlantic option for wind analyses


Lots of upper divergence reflecting the large outflow

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- Iceresistance
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Re: Tropical Wave Near the Cabo Verde Islands
skyline385 wrote:Iceresistance wrote:Outflow is almost 100% complete on the convective area!
https://s4.gifyu.com/images/wg8wvir-1.gif
https://s4.gifyu.com/images/wg8wvir-1.gif
Comparison from previous update
https://s4.gifyu.com/images/wg8wvir.gif
https://s4.gifyu.com/images/wg8wvir.gif
(Again, the bottom right corner is where it is)
CIMSS has an East Atlantic option for wind analyses![]()
https://i.imgur.com/u2J2wGE.png
Lots of upper divergence reflecting the large outflow
https://i.imgur.com/6igamdv.png
Yep, I'm watching it, this was unexpected in terms of location, I'm thinking that the NHC may have to have a secondary area of AOI because of that system
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Bill 2015 & Beta 2020
Winter 2020-2021
All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
Winter 2020-2021

All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
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Re: Tropical Wave Near the Cabo Verde Islands
skyline385 wrote:Looking at all these weak & broad vorticity centers it is going to need a LOT of consolidating before it starts developing. One of those centers is actually the size of Florida![]()
https://i.imgur.com/nkNj4wD.png
Most of the vorticity analyzed there is associated with the monsoon trough and not so much the wave axis. Below I've highlighted the wave axis in pink. Watch for the southern vorticity lobe associated with the monsoon trough here (red), it should pivot north along the wave axis later tonight/tomorrow and then amplify as it pivots towards the southwest further west near 40W:

18z ECMWF through 90 hours shows this evolution excellently:

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Re: Tropical Wave Near the Cabo Verde Islands
00z GEM finally woke up and is developing this.
00z GFS seems to have corrected and is developing this as well.
00z GFS seems to have corrected and is developing this as well.
Last edited by Landy on Thu Aug 25, 2022 11:25 pm, edited 1 time in total.
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Re: Tropical Wave Near the Cabo Verde Islands
Hey look, when the GFS doesn't initialize the vorticity down by 9N it actually develops this:


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