The Eyewall

One-sentence summary

A wave near the Bahamas is unlikely to develop over the next few days, but support is growing for some development of a wave emerging off Africa later next week.

Happening now: Bahamas wave unlikely to develop

Things remain quiet in the tropics for the near-term. We do not expect any development from any areas. The most prominent feature continues to be a tropical wave near the Bahamas.

Modeling continues to view this area unfavorably, and no development is expected from it. But since we watch things closely, let’s just talk briefly about why it probably won’t develop.

Wind shear is not the issue, as this wave is embedded in an area of lower shear. But there is a fair bit of dry air around this wave. Yesterday I noted how a surge of mid-level dry air into the Southeast this weekend or early next week would likely eviscerate this wave. That’s still on track.

But given the low shear environment, we’re sort of lucky to already have some dry air around the system. Otherwise, I think it would be a potential candidate for development. We’ll continue to watch it into the weekend, just in case. But for now, we feel confident that this will not form.

Elsewhere, things are quiet.

The medium range (days 6 to 10): Model support growing for wave off Africa to develop next week. Maybe.

The next item to watch will be emerging off Africa in the coming days. We are beginning to see some actual model agreement now between the GFS and Euro that suggest a wave or waves will develop later next week. The trouble right now is that there are a lot of disturbances in that part of the world, and it’s tough to really say with any confidence which one it will be that goes, if any do at all! The European ensemble model shows this really well.

Recall, ensemble models are basically when you take the same model and run it 30 (GFS) to 50 (Euro) times with tweaks each time. If you look at the individual ensemble members, you get a more realistic spread of potential outcomes. Indeed, when you look at the European ensemble right now, you can make absolutely zero sense of things. Which wave? When does it develop? Is it multiple waves? What is life?

As a forecaster, all I can do is look at that and tell you, “Hey, a wave emerging off Africa in 3 to 5 days has a good chance of developing later next week.” That’s where our focus will be in the medium range. Confidence is not terribly high given how the Atlantic has underachieved this season. And quite frankly, this may be telling us that the Atlantic ends up too chaotic for development. That’s very much a possibility as well. We’ll see how this evolves.

Fantasyland (beyond day 10): Who knows?

I’ll be honest with you. Given the uncertainty surrounding next week’s wave off Africa, it doesn’t make sense to tinker much with the “beyond day 10” period. I personally expect this medium-range wave(s) to be the main storyline heading into the longer range, should it develop. Behind that, we’ll continue to watch the African wave train do its thing as we head toward September. You can count on us for sober, level-headed, no hype coverage of all of it in the coming weeks. If you haven’t already, tell your friends or family on the coast from Newfoundland to New Orleans to Nicaragua that we’re here to help folks make sense of hurricane season!

One-sentence summary

The near-term is quite quiet, and while there are a couple things to watch beyond the weekend, there’s nothing of any serious concern at the moment.

Happening now: Really nice for August

Things are quiet, and they’re expected to remain so over the next 3 to 5 days, with no areas of any real concern, and nothing rogue on any modeling. If we look at satellite this morning there are at least a couple areas that stand out. Certainly the storms over Missouri are notable. There is storminess off the Southeast and Mid-Atlantic coast, a disturbance north of Hispaniola, and another tropical wave entering the Windward Islands.

None of these areas looks particularly menacing though from a tropical development sense, and we expect the next five days to be storm-free.

The medium range (days 6 to 10): Next candidate for development emerges off Africa

The next period should start with a tropical wave in the Bahamas that will likely scoot toward Florida and the Gulf around day 6 (next Monday or Tuesday). A rather aggressive shot of dry air dropping south into the Southeast should act to really inhibit any development of that wave.

My guess is that tropical wave will either be dragged northwest into the coast in between the Bermuda high and the Texas heat dome, or it will get shunted off to the south and west toward Mexico. Or it may just end up getting dismantled. Regardless, no development is expected.

Behind that wave, we should see another one moving into the Antilles without much organization. Behind that wave another one should be emerging off Africa this weekend, and we’ll see where we are at the end of the medium-range period. The Euro ensemble (50+ runs of the same model with various tweaks), as it has been much of summer with main development region (MDR) waves is rather aggressive in developing this as it comes across the Atlantic, reaching about half to two-thirds of the way across by day ten. The operational Euro is emblematic of this, and you can see that on its day 9 forecast it shows modest development just east of the Lesser Antilles. This map shows what we call vorticity at 700 mb, about 10,000 feet up in the atmosphere. Vorticity can tell us where atmospheric disturbances are or how “robust” they are. You’ll periodically hear this referred to as “energy in the upper atmosphere” by some meteorologists.

Anyway, this shows that on day 9 there is one wave gradually approaching the Caribbean islands and another emerging off Africa.

The Bermuda high is expected to weaken a good deal by days 8 to 10 or so, which might imply the escape hatch out to sea will be open. Still, it’s 10 days out so we have a world of time to watch this evolve, should it even develop at all. As noted, the Euro has had an aggressive history this summer in the MDR, and it has not exactly worked out, so I’m not as confident as that particular model is in development.

Fantasyland (beyond day 10): No signs of anything specific for now

The good news about the fringe forecast period is that there is no real sign of anything specific showing up in modeling that we can point to and say “we might need to watch this.” Maybe, maybe that next wave off Africa has a chance to be the next one to watch. Maybe. You choose your words carefully this time of year, so we’ll keep watching.

One-sentence summary

While we continue to keep an eye on a couple robust looking tropical waves in the Atlantic, there has been no added support or reason to believe these are any likelier to develop this week than it appeared last week, which is to say chances are low.

Happening now: Do the wave

Looking at satellite this morning, we have two pretty distinct features in the Atlantic. If you did not know better, these might look somewhat likely to develop.

But you read our site each day, so you do know better! And what I can tell you about things today is that these remain just some relatively bulked up tropical waves. No development of these waves is expected over the next 5 days as they continue marching to the west. The leading wave should arrive in the Antilles by Wednesday, bringing bulked up rain chances with scattered showers and thunderstorms to many of the islands. The trailing wave may or may not make it to the Caribbean.

Wind shear is going to remain rather hostile across many key points across the basin, including in the Caribbean, Gulf, and southwest Atlantic.

This should act to keep any development chances of these waves very much in check over the coming days.

The medium range (days 6 to 10): Development odds remain somewhat squelched

There are a couple things to watch in the medium range but none that I think are particularly likely to develop. First, the wave entering the Caribbean early in the period that will struggle may have some potential to try and organize itself as it comes west if it can escape some of that shear above. But honestly, that’s entirely based on history. Because the models are not having it. Here’s a map that roughly shows how much uncertainty there is in the Euro ensemble (50+ runs of the same model with tweaks) forecast of sea level pressure with this wave as it moves toward the northwest Caribbean and Gulf.

There’s not much there. If there were higher uncertainty (in this case, a meaningful cluster of individual ensemble members showing development), these colors would pop more. To me, this indicates that within the ensemble spread of the 51 members from the Euro, there is not a ton of volatility. If a tropical system were likely, you’d expect volatility here. Since we don’t see this, it’s indicative that modeling senses a hostile environment toward any tropical development. So, yes, keep an eye on it, but odds seem to favor nothing over anything else.

There may be an additional wave off Africa to look at or perhaps the trailing wave in the Atlantic in the near term can try something, but all of these features are likely to have some headwinds inhibiting their organization.

Fantasyland (beyond day 10): I guess we can keep an eye on the Atlantic?

Trends this season have been very, very clear cut in modeling. A system shows itself as possible around days 10 to 13 or so, it holds in the modeling, a development area gets highlighted, and then it finds a way to fail. Now that we’re pushing through mid-August and toward late August, I don’t want to get lulled to sleep. But admittedly, I can’t help but wonder if we’re trending toward that potential again. There are some signs of a wave forming in the Atlantic in the 11 to 15 day period, but exactly how and where are up for debate within models.

So for now, we’ll say that development odds in the “fantasyland” portion of the forecast are maybe a little higher than in the medium or near-term, but I would not classify the odds as “high” by any means yet. That is good news in mid-August.