Central Atlantic tropical wave and disturbance will take a minimalist approach to development this week

Headlines

  • A tropical disturbance and wave in the Atlantic may very slowly develop this week or next weekend as it comes west.
  • There is no imminent concern of rapid development or risks to land at this time.
  • Still, check back in on this through the week to ensure nothing has changed.
  • No other development risks are seen at this time.

Tropical wave in the dust

Rumors are swirling and hype is beginning around a tropical wave in the Atlantic that several models have shown developing into a system later this upcoming week or weekend. In fact, after my Friday post, the National Hurricane Center had it on their tropical outlook. Today, they’ve got chances bumped up to about 40 percent over the next 7 days.

A disturbance and approaching tropical wave may help trigger some development in the northern Caribbean or southwest Atlantic later in the upcoming week or next weekend. (NOAA NHC)

So what is it that we’re watching? Well, it’s this wave in the Atlantic, just southwest of the Cabo Verde Islands.

The Atlantic shows a tropical wave encased in dust to the west of the Cabo Verde Islands. This may slowly develop through the week. (College of DuPage)

Admittedly, this doesn’t look like much at all. It’s being choked by Saharan dust right now, and it has little to no thunderstorm activity surrounding it for the most part. In fact, the wave emerging off Africa to its east looks far more impressive, though that one is likely to fizzle in the coming days. Meanwhile, this wave will migrate westward. By Tuesday evening, it should be just east of the Leeward Islands, still unlikely to have developed much at all.

The tropical wave will approach the Leeward Islands Tuesday night or Wednesday, unlikely to be developed much, if at all. (Tropical Tidbits)

The system will still be essentially surrounded by dry air. It will also have to contend with a bit of wind shear. All in all, through Wednesday, it seems unlikely that this wave will develop much, and for the Lesser Antilles, Virgin Islands, and Puerto Rico this will not be one to create significant impacts.

Beyond midweek there will be a little less dry air and slightly more favorable atmospheric conditions for development as it approaches the area between the Bahamas and the Florida Straits. Through hour 144 (Friday night), about half of the European ensemble’s 51 members develop this system into a formal low pressure, and none do so significantly.

About half of the European ensemble’s 51 members develop this tropical wave by early next weekend between about Cuba and east of the Bahamas. None do so in major fashion. (Weathernerds.org)

So based on all this information we have, here’s what we can say about this tropical wave:

  • Development should be slow to occur and probably wouldn’t even begin until very late in the week, if not the weekend.
  • The wave should track generally harmlessly through the northeast Caribbean and end up somewhere between Cuba and east of the Bahamas by the weekend.
  • Dry air is likely going to play a significant role in the development (or lack of development) of this wave.
  • The 40 percent odds as posted by the NHC is a perfectly fine place to be right now.

Beyond the weekend, bets are off. We’ve seen some models track this toward the Southeast, some out to sea, and some not even develop the system at all. The GFS ensemble currently favors the latter outcome, with few to no ensemble members developing this. So for now, it’s just good to keep an eye on this one and wait and see. There’s clearly nothing here yet that is definitive, and there’s no reason to get too worked up about things right now. More to come.

Beyond this one, there are no specific signs of anything to follow. Perhaps after August 10th we’ll see our next potential candidate in the Atlantic.

A quiet weekend for us, but some hints of development in the Atlantic next week

Headlines

  • Quiet for the next 5 days in the Atlantic.
  • Continuing to watch a potential tropical wave later next week in the Western Atlantic.

Watching the next wave

Hello from 35,000 feet! Just scoping out the atmosphere on my way back to the Gulf Coast. Anyway, let’s take a look at what’s doing in the tropics heading into another summer weekend

The National Hurricane Center has a clean outlook map for the next 7 days across the Atlantic. There has been some noise coming from some models for this wave in the far eastern Atlantic today.

A tropical wave in the far eastern Atlantic off Africa is getting some models enthused about tropical development later next week. (RadarScope)

The wave is currently in an atmosphere that is dominated by dust. Or at least the road in front of it is. As the wave approaches the Caribbean or southwest Atlantic later next week, it will have some dry air to fend off. The forecast from last night’s European model shows this rather well. I’m using this to illustrate what the environment may be like when it gets to that general location, not where I think it will specifically be or what it will exactly look like. So take this with a grain of salt. Or Saharan dust.

A look at where the eastern Atlantic wave could be next week, primarily focusing on the environment it’s in. Dry air and at least some wind shear will likely be in place. (Tropical Tidbits)

So yeah, this probably bears a bit of watching. But there is nothing to say that this will definitely develop into something yet. Ensemble support for this is growing somewhat, though again, no models really shoot this to the moon yet. Still, with a tropical wave in a marginally favorable environment in early August, I will at least continue to watch this.

Ensemble modeling from the Euro model earlier this morning shows lukewarm but meaningful support for something existing in the western Atlantic later next week. We will watch. (Weathernerds.org)

Outside of that, we continue to watch for the August increase. There are no other specific concerns we see at this time. Let’s check back in on this tomorrow or Sunday.

Signs of the Atlantic calm slowly breaking in early August

Headlines

  • Quiet tropics are expected to continue into the end of July.
  • Some signs of a potential tropical wave to monitor in the western Atlantic in early August.
  • More activity is expected to pick up in mid to late August.

Calm continues a little longer

The tropics continue to look pretty quiet over the next week or so, with no areas worth watching at this time.

Calendar flips into more action?

As we head into August, as we’ve been warning, it does look like the dam will begin to break, slowly at first but with perhaps more voracity as August progresses.

Yesterday afternoon’s week 2 and 3 outlook from the Climate Prediction Center do highlight the Atlantic for tropical potential north of 20 percent.

The week 2-3 tropical hazards outlook from the Climate Prediction Center highlight the western Atlantic and Caribbean through mid-August for possible development. (NOAA CPC)

This makes sense on a couple levels. As we noted the other day, it does look like a more favorable “background state” is on the way to the Atlantic basin. Additionally, there is some “buzz” in the modeling looking toward the Bahamas late next week or weekend. The Euro has been on this one for a bit, with the operational model guidance periodically showing something, including at midday today. The ensemble guidance is much less enthusiastic about this, as you can see from the 00z European EPS looking at the IQR difference map from Tomer Burg’s excellent site.

The Euro ensemble IQR difference, which indicates ensemble spread is pretty calm for later next week, with only about 5 or 6 of the 51 ensemble members even showing low pressure. (Tomer Burg)

This really lacks much support from elsewhere at this time. The GFS and its ensemble generally shows little in this region. Even the ICON (for now), which tends to overforecast in the tropics but nailed Beryl in the Gulf doesn’t have a particularly strong signal. That said, wind shear looks relatively modest next week. However, dry air may be in plentiful supply around the area with significant dust in the basin right now, which would limit development. I would say that I can understand modeling picking up on this area for possible development, but I do not necessarily think this merits significant concern at the moment. We’ve got some time, so let’s continue to watch for an uptick in showers and storms in the Bahamas late next week or weekend.

Elsewhere, we continue to see hints of more aggressive change later in August, with European weekly data now showing above normal tropical activity by late month. Not much else we can say at this point, except to make sure you’ve got your season preps complete or soon to be completed as we white knuckle our way into later August.

Another week of calm in the Atlantic, but an August flip continues to look likely

Headlines

  • Quiet Atlantic basin for another week.
  • Signs of change continue to persist in early August.
  • Mid-August could be quite busy.

Happening in the Atlantic

It’s quiet out there again today.

There is nothing of consequence in the Atlantic at this time. (College of DuPage)

There is a smattering of showers across the Atlantic but no organized waves. The Caribbean is quiet. The Gulf is mostly quiet. There is an area of thunderstorms in the Bay of Campeche. Nothing is expected to come of that area, but with thunderstorms pestering the Gulf Coast all week and this down there, you just don’t like to totally take your eyes off this area during hurricane season. Just in case.

But in general, the next 5 to 7 days look to be void of any organized tropical activity in the Atlantic, Caribbean, or Gulf.

When will this change?

The short answer: Probably after the first few days in August.

The longer answer: Let’s dive into the weeds a bit. If we look at the background state of the atmosphere in the Atlantic, it’s dominated by sinking air, which is indicated on the chart below by orange and red coloring. However, as we go into early August, I’ve circled an area of migrating rising air. You can match it to the global map below. Notice how over the next two weeks, that area of rising air in the background maneuvers its way from Indonesia to about Central America.

A plot known as a “Hovmoller” showing the Atlantic currently run by sinking air (red/orange color), but with rising air approaching by early August (blue color). (StormVista)

As this rising air moves in, it will gradually tinge the background state of the Atlantic to be more hospitable to tropical systems. Sinking air tends to suppress storm development, whereas rising air promotes it, and as this rising air passes, it will help seed the Atlantic to get ready for action as August progresses.

Could this change? Of course, but in general, this makes sense meteorologically, and this gives us some confidence that it will get busy. And given the current absurdly warm water temperatures across the entire basin, it could get quite busy.

For now, enjoy another week of general calm, and once we see signs of something we’ll address it. Look for our next update on Wednesday or Thursday.