ATL: Ex INVEST 92L - Discussion

[gatorcane]

Popcorn convection fully in progress - reminds me of 99l when it was in the MDR, though this is popping even sooner. Still not a whole lot of model support though outside of the normally bullish CMC but bears watching:

[terstorm1012]

Honestly think this will be a lot like what became Hermine. I'm still watching closely.

[gatorcane]

Mimic-TPW shows a good signature with this wave, another large one like 99L was in the MDR:

[Gustywind]

Popcorn convection fully in progress - reminds me of 99l when it was in the MDR, though this is popping even sooner. Still not a whole lot of model support though outside of the normally bullish CMC but bears watching:

Interresting post. If this stays as a rainmarker that should be good news for us but if it grow up that won't be the best scenario. So do you think that this has the potential to be a DT before it reaches the EC islands or not? What are you best guess? The models have trouble with it since the beginning... time will tell.

[SouthFLTropics]

Anybody have an updated SAL map? If I recall the SAL was really bad when this came off Africa. Perhaps it's now starting to mix it out.

[gatorcane]

Popcorn convection fully in progress - reminds me of 99l when it was in the MDR, though this is popping even sooner. Still not a whole lot of model support though outside of the normally bullish CMC but bears watching:

https://s14.postimg.org/4b7a1nb5d/avn_lalo_animated.gif

Interresting post. If this stays as a rainmarker that should be good news for us but if it grow up that won't be the best scenario. So do you think that this has the potential to be a DT before it reaches the EC islands or not? What are you best guess? The models have trouble with it since the beginning... time will tell.

The models don't think it will become a cyclone before the islands but you never know if it surprises us. That is probably why NHC gives it a 10% chance. I didn't expect it to flare up this nicely to be honest. I think it is further upstream if it can make it to the Western Caribbean where it could get interesting.

[gatorcane]

Anybody have an updated SAL map? If I recall the SAL was really bad when this came off Africa. Perhaps it's now starting to mix it out.

[Gustywind]

Popcorn convection fully in progress - reminds me of 99l when it was in the MDR, though this is popping even sooner. Still not a whole lot of model support though outside of the normally bullish CMC but bears watching:

https://s14.postimg.org/4b7a1nb5d/avn_lalo_animated.gif

Interresting post. If this stays as a rainmarker that should be good news for us but if it grow up that won't be the best scenario. So do you think that this has the potential to be a DT before it reaches the EC islands or not? What are you best guess? The models have trouble with it since the beginning... time will tell.

The models don't think it will become a cyclone before the islands but you never know if it surprises us. That is probably why NHC gives it a 10% chance. I didn't expect it to flare up this nicely to be honest. I think it is further upstream if it can make it to the Western Caribbean where it could get interesting.

Thanks for your input . I appreciate. Anyway, we should keep an eye on 92L.

[sma10]

The usual track in these instances, especially if the wave remains weak, would be thru to the W.Caribbean/Yucatan, and this is basically how the GFS is running, with development eventually in the BOC.

But an intriguing idea would be if this developed a bit earlier, say in the Central Caribbean (which is the solution of the often terrible CMC). Earlier development combined with the GFS/Euro upper air depiction of Hermine spinning off the NE Atlantic coast in 144 hrs could result in an interesting track.

[LarryWx]

The MJO is within the circle and is forecasted by consensus to mainly stay inside the circle, which in September 1995-2012 was second only to phase 1 for highest rate of TC genesis per day.

The following storms that were born in Sep. 1995-2012 while the MJO was within the circle later hit the CONUS as a hurricane:

Rita of 2005
Isabel of 2003
Lili of 2002
Floyd of 1999
Georges of 1998
Opal of 1995.

During Sep., just over 21% of the days while within the circle had a genesis during 1995-2012. That was exceeded only by phase 1's 24%. phase 2 was at 17%. All phases combined were at 16%. So, the 21% of within the circle is quite high.

All but one of the CONUS H hits and ALL of the major CONUS H hits from Sep. geneses 1995-2012 were from geneses during phase 1, phase 2, or within the circle.

(Katrina was born in August while the MJO was within the circle fwiw.)

[chaser1]

So, here's my thoughts on 92L and shot at how I perceive the following 5 days will play out. In short, I think 92L will develop at least reaching Tropical Storm strength probably between the Eastern and Central Caribbean

I hate siding with the Canadian model especially when its out there in right field all by itself . But frankly 92L is looking fairly good on satellite. I see the area as moistening up and clearly having weak rotation at some level. It is presently moving pretty quickly but I think it will slow down as it approaches the islands. We are at the climatological peak of hurricane season and there appears to be a lessening chance of 92L trying to develop while following Hermine's island hopping excursion through the islands. So, given 92L's lower latitude, I think it has the makings of our next tropical cyclone in 3 or 4 days. It is moving fast which might be a near term hindering factor AND looks to be approaching an upper trough about to cut off while also moving generally westward (or southwestward). Its this upper feature that is presently helping fan 92L's outflow through the added upper air diffluence. This same feature might also be responsible for a day of strong shear as 92L catches up to it, thus making 92L look worse in the near future and until 92L can move past it and closer to the islands. What I found interesting is that since 12Z Aug. 30, 5 runs (12 hourly) of the Canadian has insisted on some level of development. During the same period of time, none of the 11 (6 hourly) runs of the GFS have developed 92L. One obvious distinction???? If one were to look back at each of those GFS runs, you'll see that all of them dragged 92L right over those of you in the N. Leewards, Puerto Rico, and every piece of land between itself and Arizona. Meanwhile, a number of the Canadian runs did take 92L further south and into the Caribbean where its present position and southern latitude implies it may well go. So, based on present appearance, overall upper air dynamics, warm SST's, but most of all climatology... I don't see the pockets of dry air lurking not to far away to be enough of a hinderance to keep 92L from developing as it enters or within the Caribbean. Right now the upper level winds throughout the Caribbean are not conducive, however as 92L approach the islands it would appear to be moving under increasingly anticyclonic conditions which would expand over itself with an adequate degree of convection. Further downstream at about 90 hours from now, 92L "supposedly" a T.D. or stronger, would appear to be due south of a stalled Hermine off the Carolina Outer Banks, but with an elongated and stout 594 mid level ridge displaced between them. It is this point (at approx. 90-120 hr.'s) that upper air conditions would seem to be most conducive for eventual stronger development to possibly occur

[msbee]

OK, so basically we don't know right now.as usual..

[cycloneye]

OK, so basically we don't know right now.as usual..

Hi Barbara.The tropics are always an emigma on many ways as things can change a lot in one days or even within hours.Because we are at the peak of the season,we have to watch this wave just in case it begins to organize as it approaches the islands.

[cycloneye]

2 PM TWO:

A tropical wave over the central tropical Atlantic Ocean located
about 1000 miles east of the Lesser Antilles is producing only
disorganized showers and thunderstorms. Development of this system,
if any, will be slow to occur while it approaches the Lesser
Antilles and continues westward into the eastern Caribbean Sea early
next week.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...20 percent

[abajan]

[Gustywind]

OK, so basically we don't know right now.as usual..

Hi Barbara.The tropics are always an emigma on many ways as things can change a lot in one days or even within hours.Because we are at the peak of the season,we have to watch this wave just in case it begins to organize as it approaches the islands.

As usual is an euphemisma Cycloneye . We should not let our guard down and continue to monitor the situation. 92L is an emigma since it debuts, like you Luis i'm suprised by our fast the models overestimated this feature to nothing and now we have again an healthy system moving towards the Lesser Antilles. Bear watching it!

[Gustywind]

A low pressure is now attached with the twave. Note that the speed has decreased to 20 kts to 15 kts compared to the previous TWD ( 20 kts).

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 PM EDT FRI SEP 02 2016

An Atlantic Ocean tropical wave is along 43W/44W, from 21N
southward, moving westward 15 to 20 knots. Upper level
anticyclonic wind flow is on top of the area of the tropical
wave. A 1011 mb low pressure center is along the wave near 13N.
Convective precipitation: scattered moderate to isolated strong
from 11N to 18N from 12N to 18N between 41W and 52W.

[abajan]

Meteorologist Alan Archer who provides daily forecasts on various radio stations in this region, stated in a recording aired a few minutes ago (but done earlier today) that Barbados can expect winds up to 30 mph from 92L but that it won't be anything more than a tropical wave when it passes through the Lesser Antilles.

[Gustywind]

So, here's my thoughts on 92L and shot at how I perceive the following 5 days will play out. In short, I think 92L will develop at least reaching Tropical Storm strength probably between the Eastern and Central Caribbean

I hate siding with the Canadian model especially when its out there in right field all by itself . But frankly 92L is looking fairly good on satellite. I see the area as moistening up and clearly having weak rotation at some level. It is presently moving pretty quickly but I think it will slow down as it approaches the islands. We are at the climatological peak of hurricane season and there appears to be a lessening chance of 92L trying to develop while following Hermine's island hopping excursion through the islands. So, given 92L's lower latitude, I think it has the makings of our next tropical cyclone in 3 or 4 days. It is moving fast which might be a near term hindering factor AND looks to be approaching an upper trough about to cut off while also moving generally westward (or southwestward). Its this upper feature that is presently helping fan 92L's outflow through the added upper air diffluence. This same feature might also be responsible for a day of strong shear as 92L catches up to it, thus making 92L look worse in the near future and until 92L can move past it and closer to the islands. What I found interesting is that since 12Z Aug. 30, 5 runs (12 hourly) of the Canadian has insisted on some level of development. During the same period of time, none of the 11 (6 hourly) runs of the GFS have developed 92L. One obvious distinction???? If one were to look back at each of those GFS runs, you'll see that all of them dragged 92L right over those of you in the N. Leewards, Puerto Rico, and every piece of land between itself and Arizona. Meanwhile, a number of the Canadian runs did take 92L further south and into the Caribbean where its present position and southern latitude implies it may well go. So, based on present appearance, overall upper air dynamics, warm SST's, but most of all climatology... I don't see the pockets of dry air lurking not to far away to be enough of a hinderance to keep 92L from developing as it enters or within the Caribbean. Right now the upper level winds throughout the Caribbean are not conducive, however as 92L approach the islands it would appear to be moving under increasingly anticyclonic conditions which would expand over itself with an adequate degree of convection. Further downstream at about 90 hours from now, 92L "supposedly" a T.D. or stronger, would appear to be due south of a stalled Hermine off the Carolina Outer Banks, but with an elongated and stout 594 mid level ridge displaced between them. It is this point (at approx. 90-120 hr.'s) that upper air conditions would seem to be most conducive for eventual stronger development to possibly occur

Thanks for that nice post Chaser1 . So do you think that this has the potential to be a DT by approaching or (and) crossing the Lesser Antilles?

[ScottNAtlanta]

The MJO is in a much more favourable location than when 99L was in this area. That makes a big difference