Tropical Discussion 2025

[tireman4]

The Eyewall
Dust dominates the Atlantic, while the Pacific sets up for its next system
By Matt Lanza on June 26, 2025

In brief: The Atlantic should be calm over the next week, though there's a low chance of something to watch next weekend off the East Coast. The Pacific gets active again this weekend. Heat winds down and by next week a less noteworthy pattern dominates the U.S.

Atlantic dust but a little something next weekend
On the Atlantic side of the coin, things continue quiet for the next 7 days. The entire central and eastern Atlantic is basically smothered in Saharan dust right now.


Saharan dust (yellow, orange, red, pink) covered the majority of the Atlantic basin. (University of Wisconsin CIMSS)
The dust indicates the presence of dry air, which is easily seen when you look up about 10,000 feet in the atmosphere at the relative humidity across the Atlantic.


Dry air (brown) covers most of the basin concurrent with the Saharan dust. (Pivotal Weather)
The only hint of anything right now for the next 7 to 10 days will be off the Southeast coast late next week or weekend. Models have been fairly consistently showing the potential for a disturbance to emerge there and likely scoot out to sea. Model support for this is across the board from traditional to AI models. We'll keep an eye on that, but at this time, there's no support for anything of concern to the Florida, Georgia, or Carolina coasts.

Pacific back in action soon
Look for the Pacific to wake up from its short late June slumber soon. A disturbance off the coast of Mexico will have about an 80 percent chance of developing by this weekend.


A disturbance off the coast will be likely to develop by this weekend. (NOAA NHC)
While the general model consensus currently keeps this system just off the coast of Mexico, some of the more reliable guidance does keep this thing awfully close to the coast, so it's possible that impacts, at least indirectly, will be felt from about Oaxaca north to Baja as this lifts up the coast. It seems unlikely that this would be a major storm due to proximity to land, but something fairly well organized could emerge from this for a time. Worth continuing to monitor for those in Mexico.

[Pas_Bon]

BOC has a lemon now. Mexico problem.

[biggerbyte]

Never mind about the gulf watch. Yesterdays runs were stupid. Back to our original thinking.

NEXT

[Stratton20]

91L was never going to be a texas problem though, the upper level pattern was never right for that, could see a lemon issued in the NE gulf in the coming week, ensembles favor strong ridging over the SE US meaning anything that tries to form in the NE gulf or east of florida would likely get steered to the west , that is going to be something to watch

[biggerbyte]

91L was never going to be a texas problem though, the upper level pattern was never right for that, could see a lemon issued in the NE gulf in the coming week, ensembles favor strong ridging over the SE US meaning anything that tries to form in the NE gulf or east of florida would likely get steered to the west , that is going to be something to watch

Indeed. The BOC system at one small window was questionable. I think the chance of it heading north was not founded. Rush to clap on that one. It can't do that with bridging in place.

So, something forming to our east was another topic at the time. We will see about that.

[tireman4]

By Matt Lanza on June 30, 2025

In brief: Barry has dissipated. Next, we'll watch the northeast Gulf or southwest Atlantic for development by this weekend, though there's only modest support for something formal at this time. Elsewhere, Tropical Storm Flossie is likely to become another Pacific hurricane tonight, with heavy rain and tropical storm conditions for parts of the Mexico coast.

Like Tropical Storm Andrea earlier in the month, Tropical Storm Barry held that title for a full 12 hours yesterday. Two names down covering 24 total hours? We could get used to this. Anyway, now we move onto the next development chance.

Gulf or Atlantic? Who's next?
Over the next several days, we're going to see repeated rounds of thunderstorms near the Florida Panhandle or just off the First Coast in northeast Florida. By the time we get to Thursday or Friday, a cool front is going to drop into the area and basically stall out, or "wash" out nearby, a typical feature a couple times per summer.


Surface map forecast shows an approaching cool front and weak low pressure approaching Florida from the north. (NOAA WPC)
With these festering thunderstorms and an approaching front, it may be just the shot in the arm this area needs to begin to try to organize. The biggest questions right now revolve around where exactly this happens and what sort of environment it will have to organize in. We know that there will probably be some sort of disturbance that consolidates between the northeast Gulf or southwest Atlantic this weekend.


(Tropical Tidbits)
Steering currents this weekend and early next week look fairly weak, so whatever does form could scoot out into the Atlantic slowly, or drift west southwest through the Gulf. Before anyone panics over this, I think there are a couple things we can say. Systems trying to develop this close to land tend to struggle. Also, there will be a fair bit of dry air around the Gulf Coast early next week that should cause this to struggle a bit as well. Another occasional outcome is that sometimes these disturbances split up some instead of consolidating, and a piece of it would go west and another east.

In terms of model support, reliable modeling tends to be subdued in terms of how this develops, with one or two stronger outliers out of 100 or so ensemble members.

So sitting here on Monday, all we can really do is just watch the evolution of this on modeling. A couple things can be said. There should be a disturbance. There's not much support for significant development, and there is modest support for sloppy development. One thing there is high confidence in is that the Gulf Coast of Florida is going to get whacked by heavy rainfall.


7-day rainfall totals through next Monday morning. (NOAA WPC)
The current NWS forecast shows upwards of 10 to 15 inches of rain or more possible just along the coast of the Big Bend and in the open Gulf. There will likely be some street flooding issues at times along the west coast and Panhandle coast of Florida. Heavy rain may also extend back west to Mobile and coastal Mississippi. This will be the biggest impact concern through early next week. More to come.

Elsewhere
Tropical Storm Flossie in the Pacific is going to become a hurricane by tonight in all likelihood. It will pass along and off the coast of Mexico, bringing heavy rain to the coast. Tropical Storm Watches and Warnings are posted there.


(NOAA NHC)
Flossie will significantly weaken as it approaches Baja and enters much colder water. Minimal impacts are expected there, and Flossie's remnants may get directed out into the open Pacific next week.

Additional development is possible in the Eastern Pacific behind Flossie.

Comment

[tireman4]

Levi Cowan

[biggerbyte]

In my opinion, no need for a gulf watch just yet. The system in BOC is behaving as expected. There is still some conversation to be had about some potential in the N.E. Gulf. There could actually be two systems form. One heads west towards Texas. The other the opposite direction. Hmmm