Tropical Depression 9 likely to threaten the central or eastern Gulf Coast as a hurricane by the weekend

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In brief: Invest 92L is now Tropical Depression 9 and likely to become our next named storm, and it has a decent chance to become the season’s first hurricane. The storm is likely to impact the central or eastern Gulf Coast by the weekend, with a focus between Biloxi and Destin, FL right now. The potential exists for a landfalling hurricane or borderline major hurricane by the weekend on the Gulf Coast.

The forecast has slowly come into better view today for Invest 92L, which is now classified as Tropical Depression 9, and it appears, as we have been kind of warning about as a possibility, this one may be a potent one for the Gulf Coast.

(NOAA/NHC)

The area of thunderstorms associated with TD 9 looks frazzled but robust this evening. We’re coming out of the daytime minimum for tropical system thunderstorm development and should see the depression begin to perhaps more aggressively produce storms overnight.

(WeatherFront)

The center of Tropical Depression 9 is expected to drift eastward over the next day and a half as it gradually organizes. From there, we hit the inflection point where this possibly turns into something bigger. And indeed, support for something bigger is increasing today. Let’s start with what we know. We know that some of the best hurricane modeling overall, Google’s AI forecast has bumped up the potential for a hurricane and a major hurricane to approximately 90 and 45 percent respectively.

Google’s operational model from 12z Tuesday showing a track toward the central Gulf Coast, with high odds of a hurricane. (Google)

We know that whatever this is, assuming it generally follows the Google track, will eventually run into a lot of wind shear near the Gulf Coast by Friday night or Saturday, when it presumably approaches landfall.

Wind shear is likely to play a big role in what TD 9 or Isaias looks like as it comes ashore, be it in Louisiana or east to Florida on Saturday or so. (Tropical Tidbits)

That wind shear should be detrimental to the storm’s intensity (allowing for weakening on approach to the coast), but as I’ve noted on a couple occasions this week, we have seen late season cases where southwest to northeast wind shear can actually help the outflow of a storm and keep it fairly strong. So I think you need to watch this storm and assume it may come in close to peak intensity and prepare around that. That said, while 55 percent of Google’s broader (not operational) 1,000 member ensemble has the storm peaking as a major hurricane, only 22 percent make landfall as such. That seems to suggest it will come in past peak intensity. Still, it is wise to be cautious when any ensemble is flagging 22% of its members making landfall as a major hurricane.

We also know that it’s going to be traversing some of the highest oceanic heat content in the Gulf. While the Gulf itself is below average in terms of heat content (but above average in terms of water temperature), where this is likely to track will hit some of the most heat-rich water of the Gulf.

Atlantic, Gulf, and Caribbean ocean heat content, showing the only hot spot in the Gulf probably in the path of Tropical Depression 9. (NOAA)

It won’t linger long over that patch of water, so it’s unlikely to be super meaningful, but it could be enough to tip the scales one way or another from tropical storm to hurricane or hurricane to major hurricane depending on the storm’s evolution.

We know a boatload of moisture is headed for the Gulf.

National Blend of Models rainfall forecast through Tuesday. (WeatherFront)

Rain totals aren’t eye popping, but they are over a broad area. Flash flooding is likely to be an issue in spots along the Gulf Coast, as well as inland.

We know that dry air could have a big impact on the storm’s western flank.

Forecast moisture in the Gulf on Saturday showing dry air wrapping into the western flank of TD 9/Isaias. (Tropical Tidbits)

As the storm comes north and pulls in much drier, autumn air southward across Texas and Louisiana and into the western Gulf, we could see it begin to eat away at the western semicircle of the storm, and it’s possible we end up with a sloppy hurricane that has much greater impacts on the east side than the west, even more than usual.

We also know that this is probably going to lead to a bit of a potent setup for strong to severe storms in the Southeast after coming ashore. While details are not going to be worked out for a few days yet, the SPC did mention the potential for expanding severe risks Sunday and Monday in their discussion today.

So what does this all equate to?

  • Tropical development is likely in the Gulf, with advisories almost certain to begin tonight or tomorrow morning.
  • The system we are watching is likely to become a tropical storm, a strong tropical storm, and probably a hurricane at some point.
  • There is about a 50/50 shot that this becomes a major hurricane over the open Gulf before the storm likely weakens a bit at landfall. (However, the risk of the storm making landfall at peak intensity is not zero).
  • Heavy rain is likely along the Gulf Coast and inland, along with the potential for strong to severe storms Sunday and Monday across the Eastern U.S.
  • The main target area for landfall appears to be between New Orleans and Panama City, FL, with a slight edge on areas between Biloxi and Destin.
  • The storm may have exaggerated impacts on the east side of the center versus the west, meaning landfall, while not the only thing that matters, will be an important delineation for this storm’s worst impacts.
  • The timing appears to be between Friday night and Sunday morning for the worst impacts and landfall.

Folks on the Gulf Coast, particularly from Biloxi through Destin really should be preparing now for the potential of a hurricane by Friday night. While details and specifics will change in the coming days, there’s a lot we can see already that’s concerning enough to make it make sense to begin to make preparations. More to come.

Let’s get this out of the way now: The next storm’s name is Isaias, a name that is recycled from the 2020 list, which did a lot of damage on the East Coast, and in some circles was a surprise that it was not retired. It replaced Hurricane Ike on the lists in 2014. It is pronounced “ees-ah-EE-ahs.”

It only takes one: Watching the Gulf for increasing chances of legitimate tropical development

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In brief: Tropical development chances are trending up over the southwest Gulf this week. While we don’t have a fully coherent picture of what will occur, we can begin to speculate a bit on how dry air, wind shear, and the track will play out. Folks on the central and eastern Gulf Coast from just west of New Orleans through the Big Bend region of Florida will want to monitor the progress of Invest 92L.

Our disturbance to watch has been classified today as Invest 92L, and it’s an area of thunderstorms in the Bay of Campeche.

Satellite image as of 5 PM ET Monday in the Gulf. (WeatherFront)

Nothing yet. Just some unsettled weather. Over the next couple days, this is expected to gradually become better organized and a bit stronger. As of this afternoon, the NHC has pushed up the potential for development to 80 percent.

(NOAA/NHC)

So what’s going to go on here. Like I said, we expect this whole area to become a bit better organized through the week in the Bay of Campeche, and by Wednesday afternoon or so, we should have a fairly coherent area of low pressure there.

European model forecast for mid-level “spin” in the atmosphere on Wednesday evening. (WeatherFront)

It’s at this point that the models begin to diverge wildly. The GFS goes ballistic. The Google AI model begins to gradually develop it, as does Google’s 1,000-member ensemble. The AIFS model seems to follow Google’s solution, albeit weaker (though the AIFS is known for poor intensity forecasting). The European operational model peaks it as a tropical storm and weakens it on approach to the Gulf Coast, and the Euro ensemble is a mixed bag of all of the above, though with a lean toward an AIFS type outcome. So the number of solutions on the proverbial board are plentiful.

Google’s WeatherNext model showing a likely tropical storm and potential hurricane in the Gulf tracking toward the central or eastern Gulf Coast by the weekend. (Google)

I feel like the operational version of Google right now feels like a healthy compromise. Still a chance nothing comes of this, but also a 30 percent chance of a hurricane, or perhaps a 5 percent chance of a major hurricane. We’ve seen model guidance come into better agreement today, and we will want to study trends tonight for any sort of signals we can pull.

In the meantime, it seems like a significant rainstorm will precede a potential tropical storm or hurricane impact this weekend on the Gulf Coast, somewhere east of central Louisiana.

NBM model rainfall forecast through Monday morning. (WeatherFront)

I don’t want to overlook the heavy rain impact of this system because that’s going to happen whether this is a tropical storm, hurricane, or nothing at all. So, from that point of view, we’re looking at a potential for some areas of flash flooding on parts of the Gulf Coast this week.

But whether or not this organizes still matters from a wind, surge, and honing of the heavy rain forecast. It appears the system will fester in the Bay of Campeche for a couple days before beginning to turn eastward or northward by later Wednesday or Thursday. There will be a lot of things influencing and dictating the outcome here. For one, wind shear, which is expected to be plentiful in the northwest Gulf but less so in the central Gulf.

Wind shear forecast the Gulf later this week showing strong shear in the northwest Gulf. (Tropical Tidbits)

Keep in mind that wind shear has not always acted as destructively on tropical system intensity as expected, especially along the Gulf Coast and in recent years. While shear is generally going to act against development and strengthening, there have been cases where northward moving storms toward the Gulf Coast have had their outflow aided by wind shear leading to maintained intensity or even strengthening. We can also get weird behaviors when storms are transitioning more toward extratropical cyclones than classic hurricanes. In other words, while wind shear is going to be a topic with this system, if it can organize in the next few days, I would not be fully convinced that is necessarily a negative. That said, this does look rather strong, and it may be a bit tough to fully overcome.

In addition to the wind shear as a result of the pattern over the Gulf and Southeast, there’s also the situation regarding the next Pacific storm, which will likely be named Simon. If that can outdevelop Invest 92L, it could impart more destructive shear on 92L, leading to weaker development. This seems be a low likelihood (but not an impossibility) right now.

Last, we always need to watch to see if dry air is going to be an issue. Much of Texas and the Gulf Coast has or will see rain, but some notably drier air pushing offshore of Texas is likely to get drawn into the storm in the Gulf. This will probably yield at least a somewhat lopsided system, with much greater impacts east of the center than west.

Relative humidity is likely to play a role here, probably leading to a more lopsided storm and a much less intense western half. (Tropical Tidbits)

So, we have a long way to go here. At this point it looks like whatever it is will sweep north over the weekend. That leaves us a couple days to watch developments here before folks would need to prepare in earnest anywhere, if at all.

Bottom line:

  • Gulf development risk is increasing.
  • Potential ranges anywhere from a sloppy, disorganized system to a major hurricane.
  • A “worst case” type outcome is unlikely here because of the hurdles related to dry air and wind shear.
  • Likely track aims to between southeast Louisiana and the Florida Panhandle.
  • Regardless of development, heavy rainfall is likely on the Gulf Coast this week and weekend.

Stay tuned here and to your other favorite sources of weather information for updates in the coming days.

Are we heading into the grand finale of the otherwise tepid 2026 Atlantic hurricane season?

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Happy Sunday! The National Hurricane Center introduced a lemon on the map for potential tropical development over the next week earlier. It is now an orange, indicating a 40 percent chance of tropical development.

(NOAA/NHC)

This one happens to be in the southwest Gulf and Bay of Campeche, a typical launching point for tropical systems this time of year, and occasionally a place where some bigger storms can still emerge. It’s not much today, but over the next 2 or 3 days, we are likely to see a more coherent disturbance try to organize in the area of the Bay.

(WeatherFront)

Models have been on again/off again in terms of how they see this playing out. Google Deep Mind’s 1,000 member ensemble had actually had pretty strong odds earlier this past week before fading them the last 2 or 3 days. However, just in the last 24 hours, we’ve seen a shift back to a higher likelihood of development, with about half of the members doing something here.

(tcatlas-org)

So there are three things here: First, does this even develop at all? Second, how strong could it get? And third, where does it go?

The first question is the only one that has a reasonable answer right now, and that is that there is a reasonable chance, probably better than 50 percent that this does develop into at least a tropical depression. The tail end of a cold front that has delivered a bunch of rain to the Central U.S., especially Texas over the last few days is going to establish in the Gulf as the week goes on. As thunderstorms develop and fester down there, this is where we expect some organization to occur.

Upper air pattern later this week over the Gulf. (Pivotal Weather)

This setup seems to suggest a bit of a mess. A stalled front, a loosely developed tropical system, exceptionally warm water. Gulf of Mexico sea surface temperatures are at record levels for this time of year.

Water temps are the warmest they’ve been in the satellite era in the Gulf for early October. (University of Arizona)

But warm temperatures can only carry a tropical system so far. For further development, you need moist air, unstable air, and generally low shear. It would appear that the moisture and shear will be cooperative for tropical development. Will the instability? Good question. So sitting here about a week out from whatever it may be that threatens, we can say a couple things.

First, tropical development is plausible, but we cannot really speculate on how far it will go. The potential ranges from sloppy tropical depression or storm (the story of 2026) to something fiercer. The 90th percentile intensity outcome on the 50% of Google ensemble members that develop this system is a major hurricane. Given the record warm temperatures there, I would not rule anything out. A track generally north or northeast seems reasonable as well, putting Louisiana through Florida on some notice (not likely Texas). But I think what we are most confident in at this point is a heavy rain event for the Gulf Coast and Florida.

Rainfall forecast from the European AI ensemble over the next 8 days. (WeatherFront)

Rain totals could approach double digits near the Florida Panhandle. Substantial rainfall is expected on the Gulf Coast, as well as in North Florida, mainly above I-4. Flood watches are already posted near Tallahassee and in southwest Georgia

So what’s the play here? Stay tuned, as it will be an interesting week. This hurricane season has been absolutely dead quiet, but it’s those types of seasons that can occasionally produce unpleasant one-off surprises. We don’t expect that here, but it is something we’ll watch.

Flooding event escalating a bit in the Southwest with eyes on interior Texas tomorrow night through Friday

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In brief: Heavy rain is causing widespread instances of flash flooding in the Southwest. This is likely to expand into Colorado, the southern Plains, and west or central Texas tomorrow and Thursday into Friday. The Atlantic tropics remain uneventful. We may see that change in a week or so, but it’s too soon to say what that could mean.

Good evening to everyone except the Atlanta Braves and Chicago White Sox. (Your author is a Phillies and Astros fan)

Let’s see where we are with the ongoing rainstorm in the Southwest and Texas, and we can talk tropics as well.

Polo Remnant Rain

A lot of rain has fallen over the last day and a half or so in the Southwest and parts of Texas. We’ve seen as much as nearly 5 inches of rain southwest of Tucson.

Radar estimates a widespread 1 to 3 inches across Arizona and New Mexico, with numerous flood advisories and flash flood warnings as of early Tuesday evening. (WeatherFront)

We have our first “emergency” of the event, as a small portion of Doña Ana County in New Mexico near Rincon is at risk of severe flooding due to a levee breach.

Rincon, NM is under a flash flood emergency, as a levee has breached near the water treatment plant. (WeatherFront)

Rincon has seen nearly 6 inches of rain this month, almost half of which has fallen in the last 48 hours.

The entire region remains under a moderate risk (level 3 of 4) for excessive rain tonight. That shifts north and east some tomorrow, but still, portions of eastern New Mexico could see some heavier rainfall, as model forecasts are on the order of 2 to 6 inches or more, depending on which model you look at. The tropical and convective (thunderstorm) nature of this rain is such that localized areas can easily receive 1 to 3 inches of rain in a couple hours, which is when the risk of severe flooding increases.

Rainfall from this evening through Wednesday evening as forecast by the REFS ensemble, showing a widespread 1 to 3 inches. There will likely be areas with higher amounts, particularly in the higher terrain of northern New Mexico, southern Colorado, or in central and northern Texas and Oklahoma. (WeatherFront)

The highest risk of those more squirrely amounts would be in southeast Colorado or northern New Mexico. You can see those pockets of oranges showing up on the map above in those areas.

A moderate risk of flash flooding includes Pueblo, southeast Colorado, and extreme northern New Mexico on Wednesday. (NOAA)

For Texas, the situation is a little trickier. A slow-moving line of storms is going to move from West Texas into Central Texas tomorrow night, and as it does, locally torrential rain will occur. The good news is that it’s been relatively dry here late this summer. The bad news is that anytime you add 3 to 6 inches or more of rainfall in a short time, flooding can occur. This is the challenge tomorrow night and Thursday morning in parts of Hill Country.

A moderate risk of excessive rainfall for tomorrow night is in place across most of Hill Country into the western fringe of DFW and north through central Oklahoma. (NOAA)

If we look at the probability of any location seeing 5 inches or more of rainfall, what I would deem to be a more serious flash flooding threat, you can see a bullseye showing up near or south of San Angelo. Don’t zero in too closely on the exact location of this bullseye, as it’s going to be a fluid situation. But you can see those odds creeping up to 80 percent or higher. This mean that somebody, likely between Del Rio and San Angelo and west of Kerrville is going to see 5 to 10 inches of rain tomorrow night, likely to trigger some flash flooding and, locally, some serious flash flooding. The same holds true north and west of Fort Worth.

The odds of 5 inches or more of rain tomorrow night are highest in southwestern parts of Hill Country, as well as north and west of Dallas and south of Oklahoma City. (WeatherFront)

On Thursday night and Friday, this risk will shift east into the I-35 corridor to include DFW, Waco, Austin, and San Antonio. I think the risk is a little more isolated on Friday than it looks tomorrow night, but there is at least the potential for some locally torrential rainfall. And, indeed, a moderate risk for flooding exists on Thursday night/Friday AM too.

A moderate risk of flooding covers the urban corridor of Central Texas for Thursday night and Friday. (NOAA)

Bottom line: Folks in Texas, Colorado, New Mexico, and Oklahoma should be prepared for locally significant flash flooding tomorrow through Friday.

For the Houston area, check out Space City Weather for the latest on how this weather will impact that area, as we don’t expect quite the significance of flooding risk there that we see to the west.

Atlantic tropics remain futile

The eighth named storm of the docile 2026 Atlantic hurricane season formed yesterday, with Tropical Storm Hanna forming east of Bermuda. It heads out to sea and will weaken. Tropical Storm Fay’s on again/off again relationship with tropical storm intensity blossomed again yesterday only to end today. Now, Fay is officially a post-tropical cyclone, with the final advisory issued this evening.

Tropical Storm Hanna should dissipate soon in the North Atlantic. Fay is officially dissipated now in the open Atlantic. (WeatherFront)

Fay managed to rack up only 3.8 units of ACE, despite 39 advisories, which has to be close to a record for futility. That represents 40 percent of the Atlantic’s ACE to date, which should finally breach 10 units tonight. Compare that to a normal value of 95 ACE units by October 1st.

Over the next week, things should remain quiet. It continues to appear like the southern or eastern Gulf will get a little more active in about 7 to 10 days, but we continue to have no real specific read on what disturbance it would be, where it would come from, etc. It’s basically an uncorroborated threat that we will continue to monitor for now and update on by Friday if it becomes more material. At the least, I would expect to see a potential uptick in heavy rain risk in Florida in a week or so.