Busy Atlantic without big risks for now, but we realistically speculate on what happens next

In brief: None of the currently highlighted areas in the Atlantic will threaten land. We discuss some of the speculation surrounding what may come next in the Atlantic, which is probably something of note but what exactly that is is very much TBD. Also, today is the first day since mid-June without a level 2 or higher risk of flooding somewhere in the U.S., ending a remarkable and painful 46-day streak.

The current trio

We’ve seen few changes in the overall expectation that the current three systems highlighted in the Atlantic are unlikely to be threats to land.

Disturbance off the Carolinas

Good news overall. The system off the Carolina coast has not shown any further signs of development, and it appears that its best chance to do so will be on exit from the East Coast as it generally follows Dexter’s path out to sea.

There’s just not much doing off the coast of the Carolinas. (Weathernerds.org)

Development odds have been reduced to 30 percent here as the system exits stage right. At this point there is no sign that this will impact land as it moves away. It could meander a little for a couple days south of Atlantic Canada but it currently looks to be far enough away to avoid any impacts.

Invest 96L in the deep Atlantic

Invest 96L has a few thunderstorms but little organization whatsoever. (Weathernerds.org)

The Atlantic wave got tagged as Invest 96L today, so now we can see some additional forecast data on this in the coming days. Currently, there’s not much to this. But models do indicate that in the coming days, we will see some development. It’s expected to continue to move somewhere between west-northwest and due northwest, which should keep it well north of the Caribbean islands. From there, it still seems likely to find the escape route north and northeast out to sea. Odds of development are 60 percent but odds of land impacts are close to zero at this time.

Tropical Storm Dexter clinging to life

Dexter will likely turn extratropical by this afternoon as it races out to sea. The transition to extratropical just means that it’s no longer deriving its energy from the warmer water and tropical processes. Rather, it’s now behaving more like a nor’easter and being driven by other meteorological processes, acquiring fronts, etc. In the case of Dexter, it is likely to become a hurricane-force non-tropical low pressure, or essentially a major cyclone over the open ocean that isn’t a tropical system. Hazardous for shipping, may produce some rough seas off Newfoundland but nothing more than that.

Dexter is showing signs of a cold front trailing on the south side of the storm, a tell-tale signal that a tropical system is beginning to transition into an extratropical one. (Tropical Tidbits)

Dexter should eventually end up absorbed into a system or two approaching Europe next week, unlikely to produce any major impacts there.

Speculating on the Atlantic’s future

We’re starting to notice the “churn” in comments, posts, questions, etc. that usually begins to happen in August. Much of it focuses on what this model or that model did during a specific run. Yesterday’s fun and games came courtesy of the evening GFS operational model, as it often does (earning it the nickname the “happy hour run”), which decided that one storm wasn’t enough, so it would plant two of them on either side of Florida on day 16. Look, you do you in terms of looking at weather data, but the GFS operational beyond day 10 is virtually useless. So, I’m going to pretend that never happened.

However…

There is good reason to think that we could have something a little more interesting by the time we get to the late forecast period. This would be more in the August 20th-ish timeframe. You can see this by looking at the European model ensemble spaghetti plot. Again, these aren’t answer keys, but rather they’re showing you what each of the 51 ensemble members is doing with a specific system. Each ensemble member is tweaked just a little to create the real uncertainty that exists in the atmosphere at any given moment due to observational capabilities and thus each ensemble member produces a unique outcome. Within that “noise,” occasionally you can derive a signal to push your confidence one way or another.

Of the European ensemble’s 51 members about 60 percent show a developing system in the main development region next week but have absolutely no agreement on exactly where this occurs. (Weathernerds.org)

In this case, we have a strong signal showing up for a system, but its track representation and intensity representation lives in a sea of noise. So what we can say with authority today is that conditions may be favorable for this tropical wave emerging off Africa in a couple days to perhaps become a development candidate somewhere in the Atlantic or Caribbean about 6 to 10 days from now. In fact, yesterday’s European weekly tropical cyclone anomaly chart does show slightly above normal chances for a system in the southwest Atlantic in week 2 (Aug 18-25).

Slightly above normal odds of a tropical system exist in the southwest Atlantic around the August 20th-ish timeframe. (ECMWF)

All this says is that there’s a slightly better chance than usual that a system could end up somewhere in the southwest Atlantic. We can corroborate this with the traditional model ensembles, as both the Euro and GFS ensembles show at least some noise in this general area. There also seems to be some AI model agreement on this as well.

All we can say definitively today is that the next wave emerging off Africa is creating some noise in model runs that make it an area we’ll probably be watching for several days. We have no idea where it’s heading or what shape it will be in when it gets there, and it doesn’t make sense to even begin to speculate on that topic. What we can do is remind folks that it’s the ramp up to peak hurricane season now, and with quiet conditions this weekend, perhaps it’s a good time to review your kits, checklists, etc. and ensure you are prepared in case this is the year for you. We’ll let you know what we know when we know it.

Lowest flooding risk in weeks

Today is the first day since June 21st that the Weather Prediction Center’s excessive rainfall outlook has not had a level 2 (slight) or higher risk. 46 straight days of slight risks or worse. If it’s not a record, it’s close.

(Iowa State Environmental Mesonet)

We will have much more to say about flooding and risks and all that eventually. I wrote a bit about flash flood warnings on my personal Substack yesterday. But I hope the folks at the Weather Prediction Center can catch their breath for a couple days now. Remarkable summer.

Welcome to The Eyewall’s new commenting system

Hey all—my name’s Lee, and I run the server side of The Eyewall (and Space City Weather, too!). Today we’re changing how comments work on both sites.

We’re moving from WordPress’ built-in commenting system to a new discussion platform called Discourse. The goal is to make it easier for us to moderate conversations, highlight thoughtful contributions, and cut down on off-topic noise. (For the longer version, see the “Start here: What is all this?! Answers within!” post on our new Discourse instance.)

Discourse logo
Discourse!

What does this mean for everyone?

Starting today, instead of leaving comments directly beneath posts on SCW and The Eyewall, readers will follow a link to a dedicated discussion thread on our new Discourse forum. That thread will serve as the home for all conversation related to that day’s forecast post. The most recent replies from the thread—right now we’re showing 20, but that number might change—will automatically appear at the bottom of the forecast post, in the same place comments have always lived.

If you want to comment, follow the link down below that says either “Start the discussion…” or “Continue the discussion…”, which will take you directly to the daily post’s discussion thread. If you haven’t created an account yet, you’ll be prompted to sign up. Once you’re signed in, you can comment as usual!

It’s still early days here and we’ll be continually tuning how Discourse integrates with Space City Weather and The Eyewall. Some things might be slightly broken at first, but we’ll do our best to stomp on any issues as soon as they’re spotted. Voice any concerns in the Forum Feedback category on Discourse, and we’ll look into them.

Thanks for sticking with us, and whether you’re a newcomer or someone who’s been around long enough to know exactly when Katy should evacuate, welcome to the new commenting system!

Lots of Atlantic noise but virtually all of it over the open ocean

In brief: A disturbance off the Carolina coast has a 40 percent chance to develop heading into the weekend, but it looks to remain offshore. Tropical Storm Dexter may intensify over the open Atlantic as it transitions from tropical to non-tropical late this week, no threat to land. The area in the deep Atlantic with 60 percent development odds remains worth watching but not likely to stir up too much trouble.

Tropical Atlantic

We’ll continue our daily check up on the areas worth watching in the tropical Atlantic — and speculate on what could come next.

Carolina coast

Starting closest to land today, some good news. The disturbance that’s expected to attempt to develop off the coast of the Carolinas appears that it will be less stuck than it appeared earlier in the week. Again this morning, there just isn’t a whole lot there yet.

The area we’re watching off the Carolinas is void of much of anything still today. (Weathernerds.org)

Initially, the thought was that we’d see development gradually through the week, followed by a very slow-moving or stationary type system off the coast. The first half of that statement is still true. Development will be very sluggish here. We won’t wake up to a tropical storm out of nowhere tomorrow. It may not be until Friday or Saturday that we see anything make a real effort to form. And from there, it now looks as though it will slowly but steadily move north and northeast, heading out to sea. Development odds have been pushed back to 40 percent this morning, indicating that this is not exactly expected to really get going once it does start to attempt development.

5-day rainfall totals peak at 3 to 5 inches near Myrtle Beach, with a widespread 2 to 4 inches between Cape Lookout and Florida. (Pivotal Weather)

In terms of impacts: Rainfall and rip currents are at the top of the list. You can see the 5-day forecast average rain totals above. Locally higher amounts are possible, especially today in interior North Carolina and Georgia, where flood watches are in effect.

You can see a broad slight risk (2/4) posted from the Piedmont south to the Georgia coast for today for heavy rain and flooding. (NOAA WPC)

A lot of the rain is actually front-loaded and not directly related to the system itself, but the whole pattern is connected. Rip current risk is moderate to high on the North Carolina coast, and if any development does actually occur offshore, that risk will hold into the weekend. Just something to be aware of if you’re beaching it this weekend in the Mid-Atlantic or Southeast.

Tropical Storm Dexter

Dexter continues to cling to life as it moves out to sea.

(NOAA/NHC)

Dexter is expected to become post-tropical tomorrow and end up north of the Azores by Sunday as a non-tropical low pressure. From there, Dexter’s remnants end up getting tied into a storm system near or north of the British Isles by Tuesday or Wednesday of next week. No big impacts are expected right now.

Tropical Storm Dexter has a lopsided appearance today. (Tropical Tidbits)

Dexter’s thunderstorms have outpaced the system itself, with the center again almost exposed entirely this morning. That’s a sign of an unhealthy storm. It’s just not in the greatest environment right now, packed with wind shear. That said, tropical systems have a funny way of doing things when they transition to extratropical systems. In Dexter’s case, while it may continue to look very sloppy, it’s likely to increase in intensity, with winds possibly approaching hurricane-force at some point in the next couple days. Thankfully that will remain over the water, though some rough seas could be generated in Atlantic Canada.

Deep Atlantic

We are watching two areas in the Atlantic. There is the one being highlighted by the NHC with a 60 percent chance of development. There is also what will probably be the next highlighted area by the NHC in a day or two.

The tropical wave associated with 60% odds of development looks a bit better this morning, while the next wave emerges off Africa behind it. (Weathernerds.org)

The 60% area looks a good deal better this morning than it has the last couple of days. We will probably see some gradual organization attempt to occur from this one between now and Friday. I wouldn’t be shocked if the 60 percent becomes a 70 or so by later today. In terms of this one’s future, it will probably have a relatively low ceiling for intensity. But a depression or tropical storm seems like a decent possibility at this time.

As the system moves, it will be steered west northwest or even northwest at times around the periphery of high pressure in the eastern Atlantic. By the time it gets to the weekend, high pressure may strengthen somewhat and force to turn back more to the west for a short time. Eventually, it will likely hit the escape hatch and get drawn back northwest and north through a weakness in the high pressure across the basin.

The system in the Atlantic will be steered around high pressure in the middle of the Atlantic, but it should find a weakness in the pattern by early next week, allowing it to escape north and eventually out to sea. (Tropical Tidbits)

This should allow the system to ultimately turn out to sea. I would say it’s probably worth continuing to monitor for the Caribbean or Southeast or Bermuda, but it’s unlikely to stir up too much trouble.

On the image atop this section, I did highlight the area behind this disturbance as one to watch as well. Model guidance keeps this one a little more southward in the Basin, which could in theory allow it to get closer to more land in 10 to 12 days. There is very little consensus on this one yet though, so for now it’s just probably the next area we’ll watch but nothing more than that.

Tropical Atlantic holding steady as the slow churn continues

In brief: Tropical Storm Dexter is sloppy this morning but continues to head out to sea. An area just off the Carolinas now has a 40 percent chance of developing, and it will likely be a heavy rain, rip current, and tidal flooding risk. Deeper in the Atlantic, nothing looks overly concerning, but we continue to see signs of life and development chances in the future.

Tour de Tropics

UnambiDexterous

Dexter is only moving in one direction, and that’s out to sea.

Tropical Storm Dexter south of a massive plume of wildfire smoke over the open Atlantic. (Colorado State CIRA)

Dexter’s center was exposed some earlier this morning, but it appears that thunderstorms have blossomed back over it after sunrise. Still, this is trending downward overall, and it wouldn’t be a shock to see Dexter go post-tropical by tomorrow as it races out to sea.

(NOAA/NHC)

Dexter’s remnant circulation will probably be absorbed by a storm system moving into northwest Europe, most likely near or north of the British Isles by early next week.

Southeast coast

Next on our tour, we look close to home. There’s not much to see this morning with just some scattered clusters of thunderstorms off the coast of the Carolinas.

Disorganized clusters of thunderstorms sit off the Southeast coast on Tuesday morning. (Weathernerds.org)

Over the next 36 hours or so, low pressure may develop in this area, however, and that’s when things may get a touch more interesting. This area was just bumped to 40 percent odds of developing over the next several days. At least today, it does not appear that whatever develops in this region will get terribly strong. But the overall environment is favorable for slow strengthening, as are water temperatures. One interesting thing about this is that steering currents don’t exactly look strong in this area. In other words, whatever this is will probably not move a ton, at least not in the first few days.

Heavy rain is likely on the coast of North and South Carolina, as well as perhaps over the Piedmont and in the Smokies. (Pivotal Weather)

The initial concern on this will be rip currents on the coast of North and South Carolina, as well as heavy rainfall. Should a system develop and organize some offshore, obviously we’d watch that for the direct tropical risks. If it just sits and spins offshore, we’ll probably want to watch for coastal flooding risks from Virginia into South Carolina.

Bottom line at this point: We should continue to monitor this area over the next couple days, especially because of its proximity to land. At this time, it seems as though rain, rip currents, and perhaps tidal flooding will be the primary issues from this area.

Wild card? A handful of ensemble members develop the low pressure area farther south, closer to Florida. While that is a minimal minority of ensemble members, it’s at least something to perhaps keep a side eye on. It’s far less likely than something off the Carolinas though.

Deep Atlantic

Last on our stop, the deep Atlantic, where the NHC continues to outline a broad 50 percent risk area.

(NOAA/NHC)

The tropical wave that is responsible for this area continues to produce little to no thunderstorm activity. There are storms to its south, but it’s spread so thin that there’s nothing to this at the moment. Over the next few days, we could see some gradual consolidation and organization occur.

There is virtually nothing to the tropical wave today. Over the next couple days, we could see some gradual consolidation. (Weathernerds.org)

This wave should move more to the west-northwest or northwest over the next few days as it makes an attempt to organize. The most likely scenario still takes this out to sea via a weakness in the subtropical ridge across the Atlantic.

More to come

Interestingly, the next wave or two that emerge off Africa may carry a slightly better chance of organizing. In fact, if you look at yesterday’s European model subseasonal forecast for the week of August 11th through the 18th, you’ll see somewhat bolstered odds of development closer to the Caribbean islands.

Slowly increasing potential for tropical development later next week across the Southwest Atlantic or near the islands. (ECMWF)

I will say, the models have been a little overzealous this year in developing risks in the Atlantic MDR in particular. Given that it’s now August and forecasts are pushing into mid-August, we should give those forecasts respect, but thus far it’s been tough sledding out there for any tropical systems. Could that continue? Certainly. So nothing is a guarantee here, but again, as you would expect heading into mid-August, the Atlantic is a little noisy. Stay tuned.