Tropical Wave East of Lesser Antilles (Is INVEST 95L)

[gatorcane]

Some model support for development of this sleeper wave further west. It is the area between 10N and 15N on right-side of image below:



GFS has a strong area of vorticity heading towards Bahamas:



CMC going with a strengthening cyclone further south:

[crownweather]

Some model support for development of this sleeper wave further west. It is the area between 10N and 15N on right-side of image below:

https://i.postimg.cc/d3f7fJ1F/goes16-ir-catl-201910121725.jpg

GFS has a strong area of vorticity heading towards Bahamas:

https://i.postimg.cc/sD35G2FB/gfs-z850-vort-watl-35.png

CMC going with a strengthening cyclone further south:
https://i.postimg.cc/VsgdTBT6/gem-z850-vort-watl-35.png

Am actually a little surprised this sleeper wave wasn't at least mentioned in the 2 pm NHC TWO w/ maybe a 10% 2-5 day probability circle.

[gatorcane]

Likely not mentioned because climatology would suggest no development that far out. Visible loop shows an impressive spin that is for sure. Looks like it is moving WSW:

https://www.tropicaltidbits.com/sat/sat ... t=vis-swir

[crownweather]

Some model support for development of this sleeper wave further west. It is the area between 10N and 15N on right-side of image below:

https://i.postimg.cc/d3f7fJ1F/goes16-ir-catl-201910121725.jpg

GFS has a strong area of vorticity heading towards Bahamas:

https://i.postimg.cc/sD35G2FB/gfs-z850-vort-watl-35.png

CMC going with a strengthening cyclone further south:
https://i.postimg.cc/VsgdTBT6/gem-z850-vort-watl-35.png

Also, 12Z ICON model also interested in this sleeper wave too & shows a similar track to the CMC.

[colbroe]

A 1012 low is now attached to this sleeper wave.

[CaribJam]

A 1012 low is now attached to this sleeper wave.

Do you think it may absorb the convection below it?

[SFLcane]

A 1012 low is now attached to this sleeper wave.

No real model signal.

0 eps members

[stormzilla]

Spins up in CMC

https://www.tropicaltidbits.com/analysi ... =z850_vort

Here in a few GFS runs.

https://www.tropicaltidbits.com/analysi ... =z850_vort

[AutoPenalti]

A 1012 low is now attached to this sleeper wave.

No real model signal.

0 eps members

That’s why they call it a sleeper wave.

[LarryWx]

As Gator mentioned, there seemed to be a bit of a low level circ per the last vis pics. What IR loops suggest to me is moderate SW shear. Per models, SW to W 200 mb winds will be present through the entire trek toward the Lesser Antilles, which I assume is common in mid Oct and is probably why activity out there this late is typically limited despite very warm SSTs. The shear isn’t progged to get high but it is likely high enough to be the reason models are keeping this to no more than a weak sfc reflection all the way to the LAs.

This sleeper wave will be interesting to follow next week due to the unanimous model support to get it to the western basin. Will there then be much of anything left to it then? The Euro suite, the best out there, says no. Also, GEFS is very quiet. So, despite the 12Z CMC’s Central Caribbean H at the end of its run, I’d say genesis chances remain low at least for now. But this is certainly going to be watched closely as it does appear to have a compact low level circulation right now. Shear had better not get too low or there could be a surprise.

Here is the day 5 12Z UKMET 850 with 200 mb winds map:

[Hurricaneman]

The 18zGFS seems to develop the northern part of the wave and send it up the east coast while a little later gets the southern part of the wave pulled into the CAG and developing a system in the western Caribbean around day 12

[LarryWx]

0Z GFS 252: has a weak low that originates from this wave that recurved from this point not far from S FL as a strong cold front captures it:



But, oddly enough, it then gets left behind and turns back WSW, goes over Cuba, and then the weakened remnants get sucked into a new low forming in the SW Caribbean at the end of the run!

[LarryWx]

0Z CMC doesn’t have an H but it does bring a sfc low more quickly through the entire Caribbean and then it falls apart over Nicaragua. Here is Hour 204 before it heads WSW into Nicaragua:

[gatorcane]

06Z GFS through the Straits and into the GOM hour 276. But does this originate from this wave or something else? I also count 4 Euro ensembles that show a low form near or over the Bahamas:



Looks like the Euro shows a slight increase in vorticity from this wave in the Western Caribbean by hour 240:

[LarryWx]

06Z GFS through the Straits and into the GOM hour 276. But does this originate from this wave or something else?

https://i.postimg.cc/nzbqfbJt/gfs-mslp-pcpn-watl-46.png

Gator,
Good point. I’m also trying to figure this 6Z GFS run out, which is similar to the 0Z GFS. It appears that when the sleeper wave gets to near the Lesser Antilles and slows, there may be a northeastern extension of this wave that may be combining with additional energy that comes in from its east. This part is hard to decipher.

Meanwhile, the sleeper low level circulation portion of the wave looks like it is rather vigorous and stronger near 10-11N, 42-44W, on this morning’s vis loops with increased convection including some lightning. Shear may be lessening. Watching this just in case. IF this were to do the unexpected and actually strengthen into a TD soon and then come into the Lesser Antilles intact, it would do what virtually no other system has done on record this late in the season from near its current position as I see only one analog on this map doing something similar:

[gatorcane]

Interesting Larry thanks for the climatological tracks. Does have a vigorous low-level signature:

[colbroe]

Pressure is now down to 1010 mb

[colbroe]

Pressure is now down to 1010 mb

[SFLcane]

Very hostile conditions surround this wave don’t see much development.

[tropicwatch]

Likely not mentioned because climatology would suggest no development that far out. Visible loop shows an impressive spin that is for sure. Looks like it is moving WSW:

https://www.tropicaltidbits.com/sat/sat ... t=vis-swir

The TPW shows the wsw movement nicely. Looks like it has SA in mind if it keeps this up.
http://tropic.ssec.wisc.edu/real-time/mtpw2/webAnims/tpw_nrl_colors/natl/mimictpw_natl_latest.gif