Tropical Wave has emerged from West Africa (Is Invest 95L)

[cycloneye]

This is the one UKMET, GFS and ECMWF develop.

A new tropical wave is forecast to emerge off the west coast of
Africa by the middle to latter part of this week. Some gradual
development will be possible thereafter while the system moves
generally westward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

[bob rulz]

All aboard the wave train....

[USTropics]

The GFS/ECMWF ensembles are showing a decent ridge in the CATL:





A lot of the 18z members are getting stuck under that ridge:


We'll see how this run plays out, but I imagine we're going to see some East Coast/GOM landfalls. A threat for the islands as well.

[LarryWx]

Thanks for doing this, Luis.

A Euro run from a few days ago had this barreling westward late in the run in the MDR only to have the next runs totally different. Also, I recall one EPS run with a good number of threatening members. Today's 12Z UKMET looks kind of scary as mentioned in the models thread. Although the Happy Hour GFS (FV3) was benign, this is what the Happy Hour GEFS (not FV3 based) has, much more threatening than prior GEFS and as compared to 92L and 93L for the Caribbean, Bahamas, and CONUS among others: 4 of these hit PR as Hs on 9/18 and then these same 4 later hit the CONUS E coast 9/21-2 as large Hs:





This projected wave is making me dizzy, but we need to monitor it as Sept 10th is still within the most risky period for genesis of E MDR waves for the W Atlantic, including the CONUS:

Exact dates of FORMATION (TD+) for 51 1851-2020 (through 9/6/20) CV storms** that hit the continental U.S. based on dates of initial FORMATION::

7/5, 7/11, 7/15, 7/31, 8/3, 8/3, 8/5, 8/7, 8/7, 8/15, 8/15, 8/16, 8/16, 8/17, 8/17, 8/18, 8/19, 8/19, 8/20, 8/20, 8/21, 8/21, 8/23, 8/24, 8/25, 8/25, 8/27, 8/28, 8/28, 8/29, 8/29, 8/29, 8/31, 9/1, 9/2, 9/3, 9/4, 9/6, 9/6, 9/7, 9/8, 9/9, 9/10, 9/10, 9/10, 9/11, 9/15, 9/16, 9/21, 9/21, 9/25

**My def. of CV storm:
tropical storm/hurricane that first became at least a TD E of 50W and S of 20N

[SFLcane]

[TheStormExpert]

It’s 16 days out, we’re safe!!

[gatorcane]

18Z GFS 96 through 240 hour animation, starts near Cape Verde islands and recurves across the Central Atlantic.

[aspen]

18Z GFS 96 through 240 hour animation, starts near Cape Verde islands and recurves across the Central Atlantic.

https://i.postimg.cc/SR2x6ykf/gfs-mslp-pcpn-eatl-fh96-240.gif

I’m a little doubtful of the recurve as of now, because the wave starts out at a lower latitude than 92L and 93L, and said recurve is a week or so out. I won’t exclude the possibility of this going into the Caribbean if it fails to get pulled north.

[gatorcane]

The 18Z GEFS parallel looks a lot different than the GEFS and more in line with the GFS and Euro op runs where most ensembles recurve across the Central Atlantic. Animation below 120 to 240 hours. The wave starts near the Cabo Verde islands. A few ensembles go further west then recurve later in the run threatening Bermuda

[Spacecoast]

09/06 18z GEFS Genesis probabilies up to 45%*...


***Probabilities of GEFS genesis occurring are calculated simply by determining whether the disturbance matches TD/TS characteristics over the 48 / 120 hour forecast window for each ensemble member, effectively each ensemble member is worth 4.55% (nens =22, including both deterministic and control as unique).

9/6 18z Details for this wave: I see that there are 10 members that meet TD criteria, butI'm really not sure what to make of it, compared to same 18z GEFS run from TT.(???)


???

BTW, the FSU says CMC/GFS/UKM prob = 77%, (NAV= 31%), for this wave, I think.

[FireRat]

well dang, all aboard the wave train! Is this future Sally or Teddy? I wonder

[us89]

well dang, all aboard the wave train! Is this future Sally or Teddy? I wonder

Will likely depend on whether the low south of Bermuda ever develops.

[CrazyC83]

This is reminding me so much of the active period in 1995 when we had Humberto, Iris, Jerry, Karen and Luis all in rapid fire...if there are so many out there, it would be hard for all of them to recurve, at least 1 or 2 of them would likely make it at least to the islands, if not the CONUS.

[Hypercane_Kyle]

00z ECMWF has this becoming a powerful hurricane as it moves across the MDR.

[SFLcane]

EPS sure getting is interesting similar to GEFS with some now taking this wave into the GOM and Caribbean.

“ Bottom cluster “

[Shell Mound]

This is reminding me so much of the active period in 1995 when we had Humberto, Iris, Jerry, Karen and Luis all in rapid fire...if there are so many out there, it would be hard for all of them to recurve, at least 1 or 2 of them would likely make it at least to the islands, if not the CONUS.

If the first two CV systems—TD Seventeen and 93L—curve OTS, as seems most likely, then the third system is likely to do so as well. CV-type hits on the mainland U.S. are quite rare after September 18. The ECMWF shows the third system nearing or passing through the islands around September 17, so that system would be closest to the mainland U.S. after September 18, based on trajectory, forward speed, distance, and extrapolation. While some late CV hits have occurred, including Hugo (1989) and Georges (1998), they are the exception rather than the norm among CV-type landfalls on the mainland U.S. At this point I think all further CV activity, including TD Seventeen, 93L, and this AEW, is likely to miss the mainland U.S., barring unforeseen changes.

[LarryWx]

:eek:

EPS sure getting is interesting similar to GEFS with some now taking this wave into the GOM and Caribbean.

“ Bottom cluster “

https://i.postimg.cc/hGKJDXvd/52-F12-CA1-F08-C-4881-9182-AE8-EBE579-F08.png

https://i.postimg.cc/SNpYT14d/70-EE440-D-EFE7-46-F2-B1-BA-4-BD10359-DB3-D.png

https://i.postimg.cc/7Z3VtJjG/C9-EDB5-D4-3323-499-C-8-F3-C-3905-C56-D2-D77.png

Having the 3 CV systems is very confusing. Believe it or not, most of this threatening southern cluster is actually from 93L rather than from the wave still in Africa! I count 4 sub 992 mb from 93L and one sub 992 from the wave still over Africa which all threaten the SE, especially S FL, during 9/19-21. In addition one 1007 mb member hits FL from TD 17 on 9/16. So, technically, the 0Z EPS hits FL with at least one member from TD 17, 93L, and the wave over Africa! And that's not all. About 4 members hit FL during 9/11-13 from the wave SSW of Bermuda!

[cycloneye]

A tropical wave is forecast to emerge off the west coast of Africa
in a few days. Gradual development is anticipated once the system
moves over water and a tropical depression could form late this week
or over the weekend while the system moves generally westward across
the eastern Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

[aspen]

The longer this wave takes to develop or the weaker it remains, it’ll go further west, correct? Its low exit latitude and the tracks in the models that develop it suggest it could end up being a problem for the Lesser Antilles.

[SFLcane]

 https://twitter.com/webberweather/status/1302941368210411520