Atlantic development odds slowly increasing, and potential impacts from the Pacific’s 93C in Hawaii are growing

In brief: We continue to track development potential in the Atlantic over the next week or so, and things remain fairly unimpressive (though plausible). In the Pacific, a system passing close to Hawaii by the weekend is a distinct possibility, and we have an update with the latest.

Atlantic MDR system

Looking at satellite this evening, and the primary disturbance we’re watching in the Atlantic looks half decent.

(WeatherFront)

We haven’t seen it hit “invest” classification yet, but I imagine we are not too far off. Over the next couple days, this disturbance will have mostly modest conditions to work with. There’s some shear, some dry air. Nothing is perfect here. But it may be enough to allow the system to try to slowly organize.

Since yesterday, we have seen some weather modeling get a little more bullish on potential development from this disturbance. Google Deep Mind’s model in particular has moved to about 25 percent odds of development here.

That’s a bit under the NHC’s 60 percent odds right now, but it’s still a decent signal when combined with the also relatively bullish AIFS and European model. As noted above, any development here is likely to be sluggish. The system is likely to have to battle some degree of wind shear into the rest of this week and weekend. In addition, it’s probably going to be surrounded by dry air and Saharan dust, or at least close enough in proximity to it that it acts against development. Overall, there’s no reason to believe that over the next 3 to 5 days at least this thing gets anywhere noteworthy with intensity. Hence, we are of the mindset of slow development.

Relative humidity will be low on the north and west flanks of the Atlantic system all week, including here on Thursday morning. (Tropical Tidbits)

Once it gets closer to the islands, maybe it can shake some of the drier air off, but I’m not convinced just yet. Still, if you live in or are visiting the Lesser Antilles, it probably makes sense to keep some casual tabs on what this system does through the week. However at this time, it still does not appear that we’ll have much of a menace on our hands. Farther out in time, I’m not sure we can say much coherently about this system, short of it is unlikely to be a big storm. More to come, of course.

Other Atlantic disturbances

The National Hurricane Center has modest odds on two other areas. The 10 percent one in the central Atlantic will likely fall prey to shear and dry air soon. The 10 percent one in the northern Atlantic is unlikely to do anything either. Onward.

Hawaii & Invest 93C

Well, to Hawaii now, and Invest 93C. This one looks a little frazzled today.

Invest 93C in the Central Pacific. (WeatherFront)

That said, we don’t really expect development for another 12 to 24 hours or so. Look for this to gradually become more coherently put together by tomorrow. From there, two things have changed since yesterday. First, the track has shifted slightly farther north, now bringing more of the Big Island into the forecast envelope (especially if you look at Google Deep Mind’s model).

Invest 93C’s Google Deep Mind outlook. (tcatlas.org)

Second, the max forecast intensity has dropped off some. Fewer models and ensemble members bring this to a major hurricane now. After 75% or more yesterday, we now have about 35 percent today. While that’s a rather large move, it’s still a noteworthy, healthy minority of members and a solution that should be taken seriously. Basically, interests in Hawaii should be monitoring Invest 93C very closely. Impacts are possible as early as later Friday or Saturday.

Atlantic rumbling but not especially menacing, while Hawaii monitors Invest 93C

In brief: A pair of disturbances in the Atlantic are highlighted for development risk over the next week or so, however neither look particularly menacing. Generally, below average activity should continue in the basin. A potentially potent storm in the Central Pacific may develop and pass just south of Hawaii later this week as well.

Atlantic picking up a bit

Back on Friday we talked about the potential for development in the Atlantic’s Main Development region as a wave pushed off the African coast. Well, as of today, the National Hurricane Center is identifying two areas to watch for development.

(NOAA/NHC)

The front running disturbance is the one we discussed back on Friday. This one looks mediocre at best today, at least in terms of being organized.

(WeatherFront)

To be honest, modeling also looks mediocre here, with roughly 0 to 10 percent of ensemble members across the board between the Euro, Euro AIFS, and Google Deep Mind showing development over the next 3 days. Generally speaking, this wave is also heading into an area with a lot of shear and dust, so the 20% odds by the NHC may be a bit generous here.

Now, the wave behind it has a little more support. While only about 10 to 20 percent of Google Deep Mind members develop this one, a fair number of Euro and AIFS ensemble members do develop it eventually. As we noted on Friday, it seems likely that any development here is likely to have a pretty low ceiling. That still holds true. The western Atlantic is not exactly super hospitable for tropical activity right now. This is more or less August being August above all else. Wind shear remains fairly strong in the western Atlantic and Caribbean.

Google Deep Mind 1,000-member ensemble guidance for potential tropical disturbance later this week. (tcatlas.org)

Note that while the intensity on the 1,000-member Google Deep Mind ensemble increases as the storm turns northward, the number of members falls to single digits, meaning roughly 1 percent of members do this; highly unlikely.

I could foresee two likely outcomes from this wave. The first would be if it follows the Euro/AIFS logic of development, where it becomes coherent in 3 to 4 days or so. In that case, the system would be more likely to split the gap between high pressure in the Atlantic and probably curve out to sea. The second outcome is an incoherent tropical wave that makes it to the Caribbean and just gets sheared apart. Neither outcome is particularly menacing. At this point, I would say that the islands of the Caribbean should monitor the progress of this disturbance over the next week or so, however it remains highly unlikely that a severe system would impact the region at this time. Elsewhere, check back in a couple days from now and see where we are.

Other than these two systems on the board, the next thing to watch may be another deep Atlantic wave sometime the week of August 17th, which again looks minimally impressive in modeling at this time. Notably, if you look at the European subseasonal forecast from Saturday into the week of August 24th (and August 31st for that matter), Atlantic activity is expected to be below 50% of normal. This indicates to me that we are unlikely to see any significant burst of Atlantic activity the rest of this month. El Niño dominance over the basin is likely to persist.

(ECMWF)

Central Pacific and Hawaii

One area to watch that we don’t normally cover much in depth, however, is Hawaii. You can see that week 3 activity is running around 2 to 3x normal. Multiple models are pretty bullish on the disturbance out there right now, Invest 93C.

(WeatherFront)

At this point, virtually all modeling keeps this south of Hawaii, but it likely is a system to keep an eye on over the next week or so, as the northern fringe of the forecast envelope just grazes the Big Island. Fringe impacts, such as gusty winds and rough surf would be likely to impact the islands eventually.

The Google Deep Mind 1,000 member ensemble is tightly clustered south of Hawaii, but it’s close enough to continue monitoring, as well as watch for gusty winds, rough surf, and fringe impacts. (tcatlas.org)

Google Deep Mind’s ensemble is quite bullish on fairly rapid intensification of 93C, with over 75 percent of members bringing this to major hurricane status (115 mph or greater). We’ll keep tabs here too.

Atlantic tropics trying to come back to life but it will be an uphill battle

In brief: The first potential non-Gulf system of the season faces an uphill battle in the Atlantic. It’s possible something tries to develop next week, but it’s more than likely going to end up sloppy.

Let’s start big picture and take a peek at the Atlantic basin this morning.

Satellite view of the Atlantic on Friday morning. (WeatherFront)

The standout feature is a tropical wave emerging off the African coast today. Over the next few days, this wave will track west through the Atlantic. Wind shear in the eastern Atlantic is actually not too bad at the moment. But dry air? Yeah, there’s a lot of that. Saharan dust plumage all over the Atlantic basin right now.

Saharan dust dominates. (University of Wisconsin)

That looks more like July than August, but either way it’s choked with dust. This should mean anything that develops or tries to develop will struggle a bit, if not a lot. Regardless, there’s an interesting split within the models about the future of this disturbance. The physical European model, the original gold standard is modestly bullish on development over the next 4 days, with about a quarter of the 51 ensemble members developing the system.

European ensemble development chances are modest but generally low over the next few days. (Weathernerds.org)

Some develop it and kill it off pretty quickly too. Go to the AI version of the Euro and the story is, well, pretty much the same.

European AI ensemble shows a similar outcome to the physical Euro. (Weathernerds.org)

And what of the current gold standard, the Google Deep Mind ensemble? Not much.

Google Deep Mind ensemble. (Weathernerds.org)

I will say, all the models have had their moments, good and bad with genesis of tropical systems. So I’m not going to read into anything here too much. That said, the one notable takeaway here is that even the models that do develop the system to any extent (mainly the Euro) are lukewarm on its ceiling. Meaning, if you get development, you’re probably getting a sloppy system with a low top end intensity. Sloppy systems deserve love too though, so we’ll watch to see what happens here.

With that in mind, it does not appear at the moment that this system will be a serious threat to anyone downstream. It’s a reminder that despite El Niño, despite the hostile Atlantic, despite the quiet forecast it’s still August and worth checking in on things from time to time.

No other concerns are seen at this time in the Atlantic.

The quiet Atlantic will continue for the foreseeable future as El Niño tightens its grip

In brief: We check in on the state of the tropics, how El Niño is already impacting the season, and what we may see in the coming weeks. We also discuss how to not fall for engagement bait.

It’s August 3rd as I write this, and suffice to say, it has been a delightful tropical season for those of us who don’t want major hurricanes impacting communities. Arthur, while not the full cause of flooding in Louisiana and the broader Deep South, remains the most notable of our two storms so far. Our ACE has accumulated to 2.6 units thus far, not the lowest we’ve ever seen, but certainly on the lower end of the spectrum of recent years.

(University of Arizona/Dr. Kim Wood)

We typically average about 10 units of ACE by this point in the season, although that still only accounts for about 8.5 percent of total hurricane season. So, we’re a long way from the finish.

How has hurricane season been so quiet? Well, for one, it’s normal to be quiet in the first 2.5 months of the season. We’ve seen some catastrophic examples of that going awry over the years, but by and large, those years are very much exceptions rather than rules. So, climatology is your friend. But beyond that, there’s been the El Niño that has been talked up to the moon over the last few months. And it’s worthy of the hype; it’s one of, if not the strongest El Niño we’ve seen to this point in the modern era. El Niño means wind shear in the Atlantic, and big El Niños mean big wind shear. This year? No different.

Generalized wind shear since January 1. (NOAA)

Other than perhaps a few days in early to mid-June, wind shear in the Atlantic basin has been average to well above average this season. The Gulf and subtropical Atlantic has been a bit more subdued, whereas the Caribbean has been raging with shear. So El Niño is doing its thing.

And in fact, this particular El Niño remains on pace to become a first ballot hall of fame event. This event has been building and building all summer long. When you look at the total depth of the water temperature anomalies, you can clearly see that this event is absolutely romping.

Sea-surface temperature anomalies are running 5 to 10 degrees above normal (Celsius) in the subsurface waters of the Tropical Pacific (NOAA)

As a sidebar, one thing I want to make sure the general public understands about this and the media ecosystem and content creation system today: You are going to hear people start making bold proclamations about El Niño and winter. Yes, winter. In August. It’s nonsense. People will cherry pick the most exciting (read: cold/snowy) model they can get their hands on for winter to basically draw you into engagement. They’ll couch it in language like, “This is only one solution, and it’s not necessarily likely to happen, but when I see this, I take notice!” It’s a digital dopamine hit. And it’s just not right, nor is it being a meteorologist. It’s picking a cold model because they know you, the reader or viewer gets excited about that, and it will spur you into engagement, which in turn helps you to feed the beast, as it were. It used to be rogue “social mediarologists” that did this, but it has gotten far worse and extended into professionals that know (or should know) better, particularly on the broadcast side of things. And a lot of the legacy media tries to draw you in with big, bold headlines too. Bottom line: If someone is selling you a historic cold or snowy winter right now, don’t buy the hype. Sure, there could be a storm or two — as happens almost every winter. That’s not exactly a forecast; it’s called climatology. This winter is likely to be historic in some way given the El Niño, but real history points toward either a very warm planet or high precipitation values and drought in various different parts of the globe.

Anyway, off the soapbox. El Niño is feeding the wind shear machine. The other issue? Water temps. The Gulf? Warm. The Caribbean? Less warm. The Atlantic Main Development Region? Not warm at all.

(Dr. Kim Wood/University of Arizona)

We are near climo in the deep tropics. And that’s not going to cut it with this sort of wind shear environment we are in. Basically, this points to development occurring through closer to home systems that could fire up if wind shear relaxes for even a couple days at the right (wrong) time. Or by waves, disturbances, or remnant fronts that make it closer to the much warmer subtropical latitudes off the East Coast or in the open Atlantic. We could still see a few weaker tropical systems out in the deeper Atlantic. But Cabo Verde season seems increasingly unlikely to replicate what Cabo Verde’s soccer team did at the World Cup this year.

Still, watch we will. But at this time, all looks quiet the next week or two.