Tropical Wave over the Eastern Caribbean

[tropicwatch]

Starting to see some 925mb vorticity in the area of the latest flare up of convection.

[Teban54]

[Steve H.]

Well, there is some kind of circulation evident on visible satellite imagery. Let’s watch and see. It still has time to avoid SA if it is legitimate

[chaser1]

Indeed; some lower level of turning appears at 7.5N and 47W. Sustaining itself or further deepening will be dependant on central convection.

[Stratton23]

Interesting to note on the euro/ GFS if you select the 850 MB option, both the euro and gfs show this vigorous disturbance gaining latitude and tracking through the caribbean eventually ending up in the vicinity of the NW caribbean- yucatan peninsula , Euro doesn’t develop but still a weak 850mb signature can be tracked, GFS showing that development in the NW caribbean consistently may have something to do with this tropical wave

[chaser1]

As of 10:00pm this evening, an increasing defined circulation with strong convection limited to its north quadrant appears to be located near 8N & 48W with an apparent west to WNW motion. I'm skeptical about it being on the surface but it may well be making a go at it. I don't really care what the models are suggesting but I'd project 30/50 - short/long range odds to develop.

[LarryWx]

As of 10:00pm this evening, an increasing defined circulation with strong convection limited to its north quadrant appears to be located near 8N & 48W with an apparent west to WNW motion. I'm skeptical about it being on the surface but it may well be making a go at it. I don't really care what the models are suggesting but I'd project 30/50 - short/long range odds to develop.

Hey chaser, Do you think there’s enough Coriolis force way down at 8N to get this to spin up into a TC? I count only 7 TCGs that far S with way more near 10N.

[Stratton23]

LarryWx if you look at the 12z euro 850 MB map, despite not developing it does have this wave gaining latitude in the next 2-3 days and actually moving into the caribbean, eventually ends up in the NW caribbean sea near the yucatan peninsula, its possible this could develop if it manages to gain enough latitude in time to avoid SA

[chaser1]

As of 10:00pm this evening, an increasing defined circulation with strong convection limited to its north quadrant appears to be located near 8N & 48W with an apparent west to WNW motion. I'm skeptical about it being on the surface but it may well be making a go at it. I don't really care what the models are suggesting but I'd project 30/50 - short/long range odds to develop.

Hey chaser, Do you think there’s enough Coriolis force way down at 8N to get this to spin up into a TC? I count only 7 TCGs that far S with way more near 10N.

.

Yes I do however..... I'll also admit that the Coriolis force could well be outweighed by the shorter term impact of a strong deep layer flow that within a given region, might still force a tropical cyclone westward. Even more likely would be for this disturbance to still remain entirely shallow, in which case it's motion would remain at the mercy of the low level Easterlies (unless or until a little bit of a vertical structure were to begin to develop).

[chaser1]

Further analysis suggests that a potential center would appear to be under the southeast side of a small but currently expanding CDO. SST's are 29C (and rise to 30C just east of the Southern Windwards and around 10N). Present outflow nicely expands out to the west and north quadrants. The disturbance itself appears to be the leading edge of significantly moist flow environment, with the CDO feature essentially just outside the dry line demarcated by the much dryer air to its west.

It remains to be seen for this disturbance to develope and maintain a singular CDO co-located with an apparent LLC. It could soon go poof following DMAX but it its identity is maintained into tomorrow, then it wouldn't be unreasonable for a TD to develop just east of or while passing through the Windward Islands.

[Stratton23]

Chaser1 worth watching if it gets into the caribbean, this looks like the wave that the GFS has been consistently developing in the western caribbean, it can be tracked on the 850 mb level

[Teban54]

So far tonight, a nice burst of deep convection has sustained itself, even though alignment with the center could be better.

[chaser1]

Starting to see some 925mb vorticity in the area of the latest flare up of convection.

I'm really having difficulty with the models as a whole. Days ago the GFS was forecasting 91L to develop into a TS but eventually dropped it. Now, it doesn't seem to acknowledge an established tropical disturbance approaching 50W. I can't help but wonder what broke.... bad data, less data collection, data computing issues, or just some new magical meteorological phenomenon impacting our basin (or overall Climate) that science seems challenged to get ahead of and understand?

[chaser1]

So far tonight, a nice burst of deep convection has sustained itself, even though alignment with the center could be better.

[url]https://i.postimg.cc/hjTKqhP3/15559184.gif [/url]

[url]https://i.postimg.cc/brPpY8ZY/15559184-1.gif [/url]

The result of Easterly shear perhaps? I would think that continued convective bursting might overcome light easterly shear. Just the convection part is a big "if" atm.

[chaser1]

Chaser1 worth watching if it gets into the caribbean, this looks like the wave that the GFS has been consistently developing in the western caribbean, it can be tracked on the 850 mb level

I think you're right. I was suspecting that was the case but had not had the time during the last few days to go back and compare 91L and this disturbance. If the same, and for no other reason then the "attendant" mid level energy to the north of 91L finally being pulled further away, then that alone would seem to better allow a low level feature to possibly develop & deepen.

[AJC3]

Stitched MON evening METOP-B and METOP-C ASCAT passes. Looks like the broad, ill-defined center was near 9.5N 46W about 6 hours ago. Roughly 24 hours,ASCAT showed a broad center near 7.9N 40W, so it is gaining latitude, and likely enough to avoid running into SOAM. But we'll see what happens when it enters the accelerating easterlies of the eastern Caribbean "graveyard".

[LarryWx]

Chaser1 worth watching if it gets into the caribbean, this looks like the wave that the GFS has been consistently developing in the western caribbean, it can be tracked on the 850 mb level

I think you're right. I was suspecting that was the case but had not had the time during the last few days to go back and compare 91L and this disturbance. If the same, and for no other reason then the "attendant" mid level energy to the north of 91L finally being pulled further away, then that alone would seem to better allow a low level feature to possibly develop & deepen.

What’s odd is that the 0Z EPS shows a well defined TC moving WNW toward the northern Leewards (so quite a bit of N component), but from only one member of the 50! The 18Z run has also exactly one member! And the GEFS/GEPS have none.

[GCANE]

Looks like the low-level vorts are not well aligned, with the convection well to the west.
It really needs to start picking up the high TPW air from the Amazon.
Watching.

[LarryWx]

Chaser1 worth watching if it gets into the caribbean, this looks like the wave that the GFS has been consistently developing in the western caribbean, it can be tracked on the 850 mb level

I think you're right. I was suspecting that was the case but had not had the time during the last few days to go back and compare 91L and this disturbance. If the same, and for no other reason then the "attendant" mid level energy to the north of 91L finally being pulled further away, then that alone would seem to better allow a low level feature to possibly develop & deepen.

What’s odd is that the 0Z EPS shows a well defined TC moving WNW toward the northern Leewards (so quite a bit of N component), but from only one member of the 50! The 18Z run has also exactly one member! And the GEFS/GEPS have none.

And I can now add the 6Z EPS as having one member with a TC from this. It’s the 3rd EPS run in a row with exactly one member developing a TS+ from this that then goes WNW to NW toward the N Leeward Islands (plenty of N component).

[tropicwatch]

Convection is being persistent and not all over the place.