Onda tropical al suroeste de Cabo Verde (0 - 40%)

[Silvio29]

Estimados foristas: anoche le dije a Cycloneye que en la mayoral de las veces el NHC reportaba que una onda inicialmente tenia conditiones favorables para desarrollo pero que posteriormente decia que la onda se contraria mas tarde con condiciones menos favorables para su desarrollo. Pero como en la onda actual invertieron la secuencia anteriormente especificada, entonces me luce que pudiera desarrollarce! Saludos a todos, Abito.

Estimado Abito, como este no es un año normal, cualquier cosa que parezca al revés no me extrañaría.

[David.79]

Notamos en la mañana de hoy, un cierto nivel de enmorcillamiento de la onda que va por la 40W majomenos.

No queremos ser rocaizquierda y decir esta si y aquella no como en el caso de Laura, que nació de un disturbio distinto a la Onda originalmente señalada.
En este caso, hay mucho más separación y la onda tampoco es que esté mostrando mucho en los mapas...pero si ha habido un aumento en la vorticidad en la superficie y esta mañana ha ganado nubosidad de manera sustancial (anoche venía en fase invisible).

El hecho es...que, sabemos que esperan por Nana con la onda recién salidad de Africa...pero hay mucho viento cortante en esa zona...será un proceso leeento, si acaso lo logra.

En ese aspecto, esta onda de la 40W ya pasó la peor parte...habría que ver si la pelota de SAL que la arropa cambia a amarillo pollito en par de dias y le permite ganar organización a medida que se acerca a las islas.

[albertopr]

Se ve sospechosa, ahora veo q la discuten aquí, deja cerrar topic. Parece q esta si se forma.

[StormWatch]

El CMC la desarrolla ... Interesante

[Arlequín]

El CMC la desarrolla ... Interesante

El UKM lo muestra bastante bien...

[azotame_tormenta]

Crown Weather:
Elsewhere Across The Atlantic, Caribbean & Gulf Of Mexico: Unfortunately, we are FAR from being done with this hurricane season. There are some things that I have been keeping an eye on, even though I’ve been swamped with work with Laura.

The first is a tropical disturbance that is located near the coast of Africa. Development looks unlikely for the next couple of days or so due to unfavorable environmental conditions. It is possible that the environmental conditions may become more favorable for development when this disturbance reaches about 50 West Longitude and approaches the Lesser Antilles late this weekend and early next week. While the model guidance is lukewarm at best with forecasting development of this disturbance, it’s forecasts should be used with caution as they have performed poorly with forecasting tropical cyclone genesis this season. It should be noted that the model guidance, especially the GFS ensemble and European ensemble forecasts an increase chance for this disturbance to develop once it reaches the western Caribbean later next week. So, this is a disturbance to certainly keep an eye on.

Another item to keep a very close eye on is the potential for 2 more areas of disturbed weather that may go on to develop over the eastern and central Tropical Atlantic late next week and next weekend. These potential disturbances will need to be watched extremely closely as guidance seems much more interested in forecasting development of at least 1 of them, if not both of them. In addition, it should be noted that both the GFS ensemble guidance and the European ensemble guidance both strongly hint that these disturbances may be a threat to the Leeward Islands between September 8 and 10 & then potentially either the Bahamas and East Coast of the United States by the weekend of September 12-13 or the Gulf of Mexico between September 9 and September 11.

Needless to say, there may be very little or no break with tracking and forecasting tropical systems for the next few weeks. It’s going to continue to be VERY busy!!

The next tropical weather discussion will be issued on Friday.

[Georges_98]

Crown Weather:
Elsewhere Across The Atlantic, Caribbean & Gulf Of Mexico: Unfortunately, we are FAR from being done with this hurricane season. There are some things that I have been keeping an eye on, even though I’ve been swamped with work with Laura.

The first is a tropical disturbance that is located near the coast of Africa. Development looks unlikely for the next couple of days or so due to unfavorable environmental conditions. It is possible that the environmental conditions may become more favorable for development when this disturbance reaches about 50 West Longitude and approaches the Lesser Antilles late this weekend and early next week. While the model guidance is lukewarm at best with forecasting development of this disturbance, it’s forecasts should be used with caution as they have performed poorly with forecasting tropical cyclone genesis this season. It should be noted that the model guidance, especially the GFS ensemble and European ensemble forecasts an increase chance for this disturbance to develop once it reaches the western Caribbean later next week. So, this is a disturbance to certainly keep an eye on.

Another item to keep a very close eye on is the potential for 2 more areas of disturbed weather that may go on to develop over the eastern and central Tropical Atlantic late next week and next weekend. These potential disturbances will need to be watched extremely closely as guidance seems much more interested in forecasting development of at least 1 of them, if not both of them. In addition, it should be noted that both the GFS ensemble guidance and the European ensemble guidance both strongly hint that these disturbances may be a threat to the Leeward Islands between September 8 and 10 & then potentially either the Bahamas and East Coast of the United States by the weekend of September 12-13 or the Gulf of Mexico between September 9 and September 11.

Needless to say, there may be very little or no break with tracking and forecasting tropical systems for the next few weeks. It’s going to continue to be VERY busy!!

The next tropical weather discussion will be issued on Friday.

Bueno, todo está dicho...! Tendremos taller por las próximas dos semanas.

[Obi-Wan]

Saludos! No recuerdo anteriormente haber leido un TWO donde mencionaran que la parte norte de una onda se moveria rapido al oeste sin desarrollo y que la parte sur se quedaria estacionaria y podria tener desarrollo mas adelante. Esa division o split de una onda en parte norte y parte sur me parece escucharla por vez primera.

Asi que tuve que ir al TWD y al mapa de superficie para entenderlo mejor.

Este es el Tropical Weather Outlook (TWO)
TWO 8/28/2020 8AM

Another tropical wave is located over the eastern Atlantic Ocean
just west of the Cabo Verde Islands. The northern part of this
wave, which should move rapidly westward over the central
Atlantic during the next few days, is not forecast to develop as it
is expected to remain in unfavorable environmental conditions.
However, the southern part of the wave is expected to be nearly
stationary south of the Cabo Verde Islands for the next several
days, and some development of this system is possible early next
week when it begins to move slowly westward over the eastern and
central tropical Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

Este es el Tropical Weather Discussion (TWD), entonces aqui entendemos que la parte de arriba de la onda se refiere a una vorticidad relacionada a una vaguada. Esa vorticidad sera la que seguira hacia el oeste sin posibilidad de desarrollo segun el NHC, y la onda localizada por la 25W sera la que eventualmente cuando se comienze a mover hacia el oeste la que tendra posibilidad de desarrollo.

TWD 8/28/2020 8AM

A tropical wave located over the eastern Atlantic Ocean near the
Cabo Verde Islands has an axis along 25W. It is moving west at 15
to 20 kt. To the northwest, an associated northern vorticity
trough is analyzed from 24N35W to 16N30W. The trough was well
depicted by earlier ASCAT data. Scattered moderate convection is
noted from 12N-15N between 24W-28W. Although conditions are not
favorable for development over the next couple of days, there is a
low chance of tropical formation in the next 5 days.

En el mapa de superficie se puede observar sobre Cabo Verde en la 25W en el eje de la onda, y entre la 30W y 35W la vaguada.

Surface Analysis Map de esta manana

[azotame_tormenta]

Crown Weather:
Tropical Disturbance Located 900 Miles East Of The Windward Islands: Over the past 24 hours, a tropical disturbance that is now just 900 miles to the east of the Windward Islands has become better organized. Satellite imagery indicates that the thunderstorm activity is scattered with this disturbance, but there is an area of deep thunderstorm activity occurring on the southern side of the disturbance. In addition, visible satellite loops indicate that there may be hints of some sort of circulation trying to form and this will be something to keep an eye on in terms of increased organization.

The wind shear environment is favorable for development with wind shear values of 5 to 15 knots over this disturbance. The only impediment to development is dry air to this disturbance’s immediate west. With that said, it seems that this disturbance has built itself a pocket of moisture that seems to be fighting off the dry air.

Taking A Look At The Model Guidance – The GFS and European model forecasts no significant development from this disturbance. Given these two models poor record of forecasting tropical development this season, I am skeptical.

The Canadian model, on the other hand, forecasts that this disturbance will begin to develop as it crosses the southern Leeward Islands and northern Windward Islands on Sunday and into the eastern Caribbean on Monday. Beyond this, the Canadian model forecasts this system to strengthen into a tropical storm in the central Caribbean by later Tuesday before tracking south of Jamaica on Wednesday and into Central America late next week.

Both the GFS ensemble and the European ensemble guidance seems to wait to show any sort of meaningful development until this disturbance reaches the western Caribbean later next week.

Here Are My Thoughts: Given that this disturbance is better organized than it was just 24 hours, which was not expected & that the environmental conditions are favorable for development, it is something to certainly keep a very close eye on.

Right now, I think that development should be slow and gradual, but it is quite possible that this disturbance could be either a tropical depression or near tropical depression strength by the time it reaches the southern Leeward Islands and northern Windward Islands on Sunday. Additional development is quite possible during the early and middle parts of next week as this system heads across the eastern and central Caribbean reaching the area near Jamaica on Wednesday.

I will be watching this disturbance extremely closely given its proximity to the Lesser Antilles and the fact that the disturbance is in an environment that is favorable for development.



Tropical Disturbance Near The Coast Of Africa: I continue to keep an eye on an area of disturbed weather that is located over the far eastern Tropical Atlantic. What looks like will happen with this system is that it will split in two with the area now near 12 North Latitude, 27 West Longitude becoming the dominant disturbance later this weekend and early next week. This disturbance may begin to very slowly move westward sometime during the first half of next week.

Beyond this, development may occur as this disturbance then begins its westward trek across the Tropical Atlantic later next week. This means that this system may not reach the area near the Leeward Islands until around September 6-9.

Unlike previous systems so far this season, the model guidance are actually showing robust development later this week. This is a bit concerning because it seems the “big” models such as the GFS and European model have vastly under forecast & under estimated the strength of tropical systems this seasons until it was too late. So, the fact that they are showing a pretty strong system (especially the GFS model) is concerning because it makes me wonder if this is going to be a really strong system.

The good part is that we have plenty of time to keep an eye on this disturbance as it may be several days, at least, until it begins to develop. Also, it is WAY too early to even start discussion where this disturbance may go and what areas may be threatened.

With that said, the ensemble guidance seems to suggest that a high pressure ridge may be anchored near Bermuda with a trough of low pressure in place across the Great Lakes region during the first several days of September. This would lead to the Leeward Islands being at potential risk of any tropical system moving across the Tropical Atlantic.

Beyond that, the track of any tropical system would hing heavily on how deep/shallow the Midwestern US trough is. There are too many scenarios to go through and it’s more than two weeks away until this particular tropical system would even be in a position to threaten the United States (probably would be near the weekend of September 12-13). So, for now we will keep an eye on this disturbance and keep you updated.

[megadicto]

Saludos! No recuerdo anteriormente haber leido un TWO donde mencionaran que la parte norte de una onda se moveria rapido al oeste sin desarrollo y que la parte sur se quedaria estacionaria y podria tener desarrollo mas adelante. Esa division o split de una onda en parte norte y parte sur me parece escucharla por vez primera.....

Ufff...gracias por este análisis!