GaWx

Yeah, that's a concern I have regarding the lead AEW wave that will start to emerge within 24 hours: shear is low and is projected to remain low in much of the E and C MDR for a good # of days. In addition and somewhat related: steering by high pressure that builds westward to its north is progged to prevent an early safe recurve and thus would likely mean a move far west into the basin, a potentially very dangerous scenario IF dry air doesn't keep it weak as suggested by various ens members as well as a couple of GFS runs. It being La Nina and August (not as high a % of safe recurves of E MDR TCs for both categories) add to the concern. Here's an updated satellite pic (IR) that shows similar to the prior pic that there may already be a weak circulation over far SW Mali despite convection having lightened up tonight:

Regarding this: Among other locations affected out of the 31 or so members, there are 3 12Z GEFS members with Hs that later directly affect PR. Also, there are 4 that later landfall on the SE CONUS as cat 2+ Hs along with several others threatening at the end of the run. If not the most threatening GEFS run to date for the US, I think this run almost has to be close to the worst run yet this season. These are almost 100% from that AEW that is currently over SW Mali and soon to emerge from Africa. Keep a watchful eye on it for ~8/25+ in the Caribbean and ~8/29+ in the CONUS. Hopefully it will not end up a problem, of course, and be careful what you wish for (not that wishing has any effect)!

Thanks, Ed. The 12Z GEFS is pretty active with this wave as there are strong members between 47W and 58W on 8/25 (the one near 60W is not from this wave):

Just to clarify for those who may not be following closely, the MH on the 6Z GFS is from the same wave that the GFS from 5 runs earlier (0Z of 8/15/22) had as a hurricane hitting the Leewards on 8/29-30. Energy/moisture that comes off Africa to lead to this developing per the 6Z GFS manifests itself as convection that is currently already centered over SW Mali near 7W, 12N, and already starts emerging from Africa tomorrow evening near 12N just as it did on yesterday's 0Z run. Because operational runs generally have little reliability going too far out in time, I think it is important to note how soon the seed from this potential trouble hits water and how far west it already is in Africa so that it can be followed closely. I just checked the satellite pic and convection can clearly be seen on IR over SW Mali.

Lmao, I need to try again as I somehow accidentally posted a link to a Mike Ventrice tweet that had nothing to do with a Andy Hazelton tweet I meant to link to: Regarding that lead wave on the 12Z EPS and GEFS (posted elsewhere from a fellow poster from Andy Hazelton), Andy is describing it as mostly an ITCZ formation as opposed to just a simple AEW although I would assume something coming off Africa is needed as a spark to set it off:

From the 18Z GFS, here is a weak sfc low near 40W at hour 228 that emanates from energy coming off Africa on Saturday (8/20) and appears to me to be the same source that formed those strong TCs on the 12Z EPS and GEFS that threatened the W basin late this month: it goes quite far west as the high to the north goes west with it and keeps it from recurving, but the wave stays weak and thus never amounts to anything on this run. Regardless, I'll probably be focusing on this wave on subsequent GFS/Euro op/ens runs:

Regarding that lead wave on the 12Z EPS and GEFS (posted elsewhere from a fellow poster from Andy Hazelton), Andy is describing it as mostly an ITCZ formation as opposed to just a simple AEW although I would assume something coming off Africa is needed as a spark to set it off:

The 12Z EPS is one of the most threatening runs yet to the Caribbean and US from an MDR system. This is from an AEW that comes off Africa late this week and first develops into a TC on many members a couple of days later near 30-40W. The slightly odd thing is that the Euro operational isn't doing anything with this earlier wave and hasn't been on earlier runs as it has had only a subsequent AEW develop a sfc low. Also, the 12Z GEFS has some members from this same wave that threaten the W basin. 12Z 8/15/22 EPS 360:

12Z EPS 228 vs 0Z EPS 240 for two MDR areas: - still has good number of members with E MDR low, the one recent Euro ops have been developing, but they're still mostly weak and there aren't quite as many members. They are more spread out. - has a bit more activity in the 45-60W region and this includes a few more of TS strength/1,000 mb or lower; the surface high to the north is a bit stronger and seems to be building westward above the low; thus, this looks like the potentially more dangerous of the two 12Z EPS MDR systems to me. Many of the members for this more westward potential form near 40W on or near 8/22. So, this would seemingly be from an AEW coming off ~8/18-20...so late this week look off Africa and see how it looks! This could be a sneaky one and is the AEW before the one the Euro ops have been developing. That's my take fwiw. It is worth the price you paid for it.

I just went with the genesis of 6 NS in September. Why? 1. 3rd year Niña analog of 2000 had 7, but ACE was much higher as of 8/15 in 2000 due to Alberto and 7 was by far largest # of Sept. NS geneses for a 3rd year La Niña. So, I reduced the 7 slightly. 2. Recent La Niña years' #s in Sept: 8, 9, 4, 5...these average 6.5 Sept. geneses. 3. Low ACE as of 8/15 analogs for non-El Nino since 1995: Sept geneses were 6, 3, 4, 7, 7.....these average 5.4 in Sept. Considering all of the above, I was deciding between 5 and 6 and went with 6. So, I now have 3 in Aug and 6 in Sep to go with the 3 we already have. So, I'm currently at 12 NS through 9/30/22.

El Niño years, not La Niña years, often have quiet seasons, especially in the MDR and often including not that much activity late. However, this season so far has been behaving during a good portion of it a bit like a typical El Niño (shear and dry air in MDR) more than like a typical La Niña fwiw. I believe El Niño years tend to have the westerlies drop down somewhat sooner on average vs La Niña years although it may be hard to prove this without hard data. It is interesting to see the "mood swings" from one operational GFS/Euro to the next. Too much imho in both directions (not just at this forum) considering the lack of reliability.

The 0Z Euro is consistent with recent Euro runs in having a CV sfc low on 8/24 (day 9) although the low is weaker and the high to the north isn't as strong. At hour 240 (8/25 0Z), it barely moves and is still near the CVs on the Euro although there's a small piece well in front. The 0Z GFS at 240 is way west of the Euro's main low (past 40W) with its lead low: 0Z Euro 240: low still only near CVs 0Z GFS 240: low already past 40W and in a more threatening position

Yep, the models may be starting to play catch up like they sometimes do when the lid comes off. The developed Euro AEW didn't move offshore til 8/22. The 0Z GFS looks like it is at least incorporating energy moving off on 8/19 (similar to 18Z GFS) and already has a weak surface low SW of the CV Islands on 8/20. Then it looks like it gets new energy coming off Africa on 8/21 that somehow combines with it on 8/22. It then gets to 40W on 8/24, the day that the Euro low is much further east near 27W. The GFS looks weird with this evolution, but if there really is going to be a low near 40W on 8/24 still that far south, this looks like it could be a real threat as it does do so at the end of the run. The 0Z UKMET has no TC through 144 (0Z on 8/21) just like it's prior run. I'm sticking with 3 NS this month.

The 18Z GEFS is rather active with the AEW coming off on 8/19 fwiw. This is the AEW preceding the one that the Euro/EPS developed.

I took a very rare midsummer walk today due to it being a beautiful evening dewpoints only in the low 60s. They actually were in the upper 50s earlier. Yesterday's were tolerable, too, though not as low.

Taking this 12Z EPS run out to 360, the most concentrated area of lower pressure is within the 40-50 W region with the most active members moving WNW near 15N and thus not showing any obvious sign of an early recurve by that point. If there were to be a TC near 15N, 45W, moving WNW on 8/29 and with it being La Nina, that would potentially be dangerous for somewhere on the US east coast though a subsequent safe recurve would still be in the typical mix of possibilities from that location. There's then also an active followup wave with the most active members just west of the CV Islands.

- I'm still sticking with 120 for my ACE prediction that goes back to late July. - I remain most concerned about the Gulf coast of FL for the highest risk this season per the eight 3rd year La Niña analogs since every one had significant to major impact there. - No TC genesis forecasted by the 12Z UKMET anywhere in the basin. - 12Z model consensus says we'll never know for sure whether yesterday's 12Z consensus of a strong storm into NE would have gotten a name due to possibly being a STS because today's 12Z consensus has only a significantly weaker system now. - If we were to go another week or so with both nothing new as well as nothing imminent on model consensus, my ACE forecast would by then have been reduced from 120.

This latest area update brings 2022 back down a decent amount vs the average of 2007-21. It is now at +330K vs the prior 15 year average for the date as compared to +390 as of three days ago. Recap of current area vs avg. of last 15 years as of: 6/15/22: +70K 6/16/22: +120K 6/20/22: +240K 6/22/22: +140K 6/29/22: -140K 7/1/22: +70K 7/10/22: +250K 7/12/22: +370K 7/16/22: +330K 7/20/22: +360K 7/23/22: +480K 7/26/22: +460K 7/30/22: +440K 8/7/22: +320K 8/10/22: +390K 8/13/22: +330K

The 0Z GFS, Euro, and UKMET have backed way off on the strong low showing up at 12Z going into the NE US. The UKMET backed off from the 12Z's hour 102 TC genesis.

12Z Euro stronger and hits NE as what imho almost has to have been a NS (probably ST) at least before this image considering the warmth of the SSTs:

12Z Euro is stronger and closer to the coast kind of similar to the UK. The key here to me is that it trended somewhat with the 6Z/12Z GFS. At hour 96, this looks like it could easily be a STD though it doesn't look tropical:

12Z UK, which is being labeled as a TC starting here, where SST is 29 C: At 120:

The 12Z UK verbatim per text actually has a TC form at 102 hrs that then goes N into NE. It forms it at 38.2 N, 71.0 W, where SST is at 29 C: NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 102 HOURS FORECAST POSITION AT T+102 : 38.2N 71.0W LEAD CENTRAL MAXIMUM WIND VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS) -------------- ---- -------- ------------- ------------- 0000UTC 18.08.2022 108 38.9N 69.0W 1005 27 1200UTC 18.08.2022 120 43.3N 69.6W 1000 27 0000UTC 19.08.2022 132 43.7N 69.6W 1002 27 1200UTC 19.08.2022 144 CEASED TRACKING

This! Like on the 6Z GFS, this forms over 29-30 C SSTs on Tuesday off NC and it remains over 29-30 C for 12 hours. It looks imho like it is at the very least a STS although I lean toward TS before possibly transitioning to a STS.

Look out on the 12Z GFS NE US!