Major Hurricane Isaias

[WxWatcher007]

The historically quiet Atlantic may have one final gasp before closing the door on the season, and this one is in the southwestern Gulf. 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Oct 5 2026

For the North Atlantic...Caribbean Sea and the Gulf of America:

1. Southwestern Gulf of America:
A trough of low pressure in the southwestern Gulf of America is 
producing disorganized showers and thunderstorms. Although 
environmental conditions appear to be marginally conducive, gradual 
development is becoming more likely, and a tropical depression is 
likely to form during the middle or latter portion of the week. This 
system is expected to drift eastward over the next few days, before 
it turns northward.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...high...70 percent.



Forecaster Kelly

 

We've all been tracking this one for a few days, and while odds have significantly increased, there's still a fair amount of uncertainty on what this one could actually become. 

While development looks likely with the geographically favorable genesis location of the Bay of Campeche (the concave nature of the region promotes spin) alongside warm SSTs and an upper level pattern favorable for divergence (promoting strong convection) there are issues with westerly shear if the system is not perfectly aligned with the jet coming from the west and potentially dry air. 

Most guidance at least at the moment is modest in intensity as it pulls the eventual system northeast into the northern Gulf coast. 

[WxWatcher007]

20 minutes ago, Seminole said:

Flood watches have been issued for most North Florida counties and some south Georgia and Alabama counties. 

Flood Watch
National Weather Service Tallahassee FL
Issued by National Weather Service Jacksonville FL
234 PM EDT Sun Oct 4 2026

ALZ068-069-FLZ007>019-027-108-112-114-115-118-127-326-426-GAZ122>131-
142>148-155>161-060000-
/O.EXT.KTAE.FA.A.0004.000000T0000Z-261006T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Geneva-Houston-North Walton-Central Walton-Holmes-Washington-
Jackson-Inland Bay-Calhoun-Inland Gulf-Inland Franklin-Gadsden-
Leon-Inland Jefferson-Madison-Inland Wakulla-South Walton-Coastal
Bay-Coastal Gulf-Coastal Franklin-Coastal Jefferson-Coastal
Wakulla-Northern Liberty-Southern Liberty-Randolph-Calhoun-
Terrell-Dougherty-Lee-Worth-Turner-Tift-Ben Hill-Irwin-Early-
Miller-Baker-Mitchell-Colquitt-Cook-Berrien-Seminole-Decatur-Grady-
Thomas-Brooks-Lowndes-Lanier-
Including the cities of Bethel, Babcock, Hoggard Mill, Dalkeith, West
Bainbridge, Capitola, Saint Joe Beach, Marianna, Vicksburg,
Mitchell Co A/P, Panama City, Metcalf, Monticello, Seminole State
Park, Simsville, Alpine Heights, Center Ridge, Freeport, Geneva,
Donalsonville, East Albany, Lockett Crossing, Yeomans, Davis Park, De
Funiak Spring Airport, Richter Crossroads, Moultrie
Municipal A/P, Dothan, Cairo, Southport, Coles, Peterson Hill,
Moultrie, Spence Airport, Howard Creek, High Bluff, Sumatra, Beverly,
Lovett, Turquoise Beach, Cottle, Cordrays Mill, Milford, Bonifay,
Chaires, Madison, Chipley, Chula, Bannockburn, Barker Store, Pelham,
Hartford, Santa Clara, Tallahassee, Ganer,
Riverturn, Doverel, Pine Valley, Ausmac, Decatur Co A/P,
Williamsburg, Newton, Commissary Hill, Holmes County Airport,
Graceville, Grady Co A/P, Iveys Mill, Bellview, Shivers Mill,
Berrien Co A/P, Hawkinstown, Tifton, Elpino, Centerville, Cluster
Springs, Nashville, Littman, Wetumpka, Killearn Estates, Pinetta,
Panacea, Albany, Fadette, Fitzgerald Municipal A/P, Lewis,
Pleasant Ridge, Camilla, Santa Rosa Beach, Lynn Haven, Apalachicola,
Nixon, Lynn, Killearn Lakes, Browntown, Festus, Cottonwood, Glendale,
Steinham Store, Dillon, Apalachicola Airport, Bainbridge, Blakely,
Bowens Mill, Courthouse, Chaires Crossroads, Grooverville, Kern, Oak
Grove, Thomasville, Twin
Pole, Dawson Municipal A/P, Barneyville, Springvale, Herod,
Quincy Airport, Early Co A/P, Cooktown, Brooks Co A/P, Cobb
Crossroads, Crystal Lake, Greggs, Odena, Little Hope, Alma,
Sandestin, Benevolence, Blue Springs, Queensland, Leonia, Wakulla
Springs, Hobby, Sweetwater, Waterloo, Palmyra, Alfords, Red Store
Crossroads, Lakeland, Cherry Lake, Ashburn, Sunsweet, Honeyville,
Magnolia Beach, Colquitt, Walker, Marysville, Buckhorn, Westwood,
Abba, Empress, Sylvester Airport, Worth, Valdosta Regional Airport,
Casa Blanco, Adel, Fort Gadsden, Graves, Hacoda, Scotts Ferry,
Branchville, Dickey, Morgan, Valdosta, Hanover, Wewahitchka, Capps,
Moncrief, Five Points, Port Leon, Pine Park,
Vilas, Elmodel Wma, Ashford, Ocilla, Port St. Joe, Pasco, Hanson,
Irwinville, Fitzgerald, Douglasville, Point Washington, Tilton,
Boykin, Cuba, Ashton, Beachton, Bennett, Drifton, Hopewell,
Arlington, Jarrott, Beacon Hill, Econfina, Enterprise, Bay City,
Turner City, Dixie, Saint Marks, Morgan Place, Harding, Mayhaw,
Dawson, Nankin, De Funiak Springs, Pretoria, Southwest Ga
Regional A/P, Sneads, Bradfordville, Bunker, Chipley Municipal
Airport, Hilliardville, Hays Place, Sylvester, Capel, Logan Field
Municipal A/P, Poplar Head, Portland, New Hope, Dills, Cook Co
A/P, Laconte, Frink, Buck Siding, Forrester, Medart, Overstreet,
Quincy, Wilma, Callaway, Cotton, Donaldsonville A/P, Abe Springs,
Quitman, Springvale Station, Clarksville, Teeterville, Maclay State
Gardens, Sopchoppy, Creels, Leesburg, Hardin Heights, Weber, Argyle,
Orange Hill, Central City, Chattahoochee, Clarks Mill, Cuthbert,
Gammage, Isabella, Fairchild, White City, Geneva
Municipal A/P, Youngstown, Durham, Gordy, Edison, Eucheeanna,
Massee, Red Rock, Malone, and Blountstown
234 PM EDT Sun Oct 4 2026 /134 PM CDT Sun Oct 4 2026/

...FLOOD WATCH NOW IN EFFECT THROUGH MONDAY EVENING...

* WHAT...Flash flooding caused by excessive rainfall continues to be
  possible.

* WHERE...Portions of southeast Alabama, including the following
  areas, Geneva and Houston, Florida, including the following areas,
  Calhoun, Central Walton, Coastal Bay, Coastal Franklin, Coastal
  Gulf, Coastal Jefferson, Coastal Wakulla, Gadsden, Holmes, Inland
  Bay, Inland Franklin, Inland Gulf, Inland Jefferson, Inland
  Wakulla, Jackson, Leon, Madison, North Walton, Northern Liberty,
  South Walton, Southern Liberty and Washington, and Georgia,
  including the following areas, Baker, Ben Hill, Berrien, Brooks,
  Calhoun, Colquitt, Cook, Decatur, Dougherty, Early, Grady, Irwin,
  Lanier, Lee, Lowndes, Miller, Mitchell, Randolph, Seminole,
  Terrell, Thomas, Tift, Turner and Worth.

* WHEN...Through Monday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Flooding may occur in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Additional rainfall totals of 2 to 4 inches are forecast for most
    of the area with locally higher amounts of up to 6 inches
    possible through Monday, especially along the Emerald and
    Forgotten Coasts. Another area of concern is across south-central
    Georgia where locally heavy rainfall since Friday afternoon has
    primed the region more so than the rest of our area, so it wont
    take as much rain to cause flash flooding. Across the flood watch
    area, very high rain rates due to the tropical air mass may lead
    to flash flooding, especially in urban and poor drainage areas.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

PK

Given that this might be a late season sprawling system, definitely a good chance this is a moisture laden system. Resharing here.

[TheDreamTraveler]

Maybe we'll break our hurricane drought with this system

[NorthHillsWx]

8 minutes ago, TheDreamTraveler said:

Maybe we'll break our hurricane drought with this system

It is possible. This storm has a runway to attain hurricane status but it not be an ideal environment. There will be westerly shear and dry air impacting the storm to some extent though if this is moving to the NE the shear vector may not be that unfavorable. Also, divergent flow aloft on the east side means this could be a strong, lopsided system. If the surface circulation gets hung up or moves more west it seems (based on ensembles) the shear and dry air win out. At this point we need a center to track before we reach any conclusions on the future environment but it is by no means going to be pristine. We have seen, especially in recent years, storms be able to overcome similar environments while heading NE so I wouldn't write this one off at all even given the look that certainly features westerly shear and continental air impacts at some point. This location is well known for overproducers too this time of year. Will be an interesting week, but at a minimum this looks to be a significant heavy rain event in the deep south and possibly some major drought relief in the Carolinas 

[MJO812]

Gfs

[NorthHillsWx]

Any idea how long the Gulf radars are expected to be down for? This could be a very bad weekend to not have radar. NWS can still view them but the public cannot.

[yoda]

7 minutes ago, NorthHillsWx said:

Any idea how long the Gulf radars are expected to be down for? This could be a very bad weekend to not have radar. NWS can still view them but the public cannot.

I only see three down?  KMOB, KTLH, and KEVX

[NorthHillsWx]

11 minutes ago, yoda said:

I only see three down?  KMOB, KTLH, and KEVX

On my app (RadarScope) KMOB, KEVX, KEOX, KTLH, and KVAX are all still down

[GaWx]

12Z UKMET: shifts back east from 0Z run’s far SE LA to MS/AL border track to new track into FL Pan for mid-grade TS followed by NNE and then NNW move in AL:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 66 HOURS
FORECAST POSITION AT T+ 66 : 22.8N 92.4W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 08.10.2026 72 24.0N 91.4W 1002 30
0000UTC 09.10.2026 84 25.2N 89.4W 999 34
1200UTC 09.10.2026 96 26.7N 88.0W 996 44
0000UTC 10.10.2026 108 28.7N 86.9W 995 49
1200UTC 10.10.2026 120 32.1N 86.1W 999 26
0000UTC 11.10.2026 132 34.5N 87.3W 1001 26
1200UTC 11.10.2026 144 CEASED TRACKING

[Nomz]

Google seems to be zeroing in on a significant landfall on the Gulf Coast. Still a long lead time though

[GaWx]

60%/80% now:

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Oct 5 2026

For the North Atlantic...Caribbean Sea and the Gulf of America:

1. Southwestern Gulf of America (AL92):
A trough of low pressure over the southwestern Gulf of America is
producing disorganized showers and thunderstorms. Although
environmental conditions appear to be marginally conducive, gradual
development is becoming more likely, and a tropical depression is
expected to form during the middle portion of the week. This system
is expected to drift eastward over the next couple of days, before
it turns northward. It is too early to determine the specific
impacts to the northern Gulf Coast, but interests there should
closely monitor the progress of this system.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...80 percent.

[eyewall]

The 12z Euro shreds it and keeps it very weak. 

[NorthHillsWx]

Now that there’s an invest we will get hurricane models this evening. Overall there’s been a significant uptick overall regarding strength on modeling today tho the AI models are definitely cooking this thing up more than the rest. Despite the overall increase from modeling, intensity ranges for this still include a very sheared lopsided weak system (see Euro). Google seems to really want to develop and move this NE quick which might be out ahead of the modeled shear later in the weekend. That might be a specific trend to watch in terms or timing possibly affecting intensity 

[NavarreDon]

This could get interesting regardless of strength if it’s not a fast mover. I’ve already had 12.69” (PWS) this month alone. Keeping my eyes on it for sure.


.

[olafminesaw]

[NavarreDon]

Good news from MOB….

https://x.com/nwsmobile/status/2107184041338306801?s=46&t=0ZvB_AF2VfA6c0SDxf53yA


.

[NorthHillsWx]

13 minutes ago, NavarreDon said:

Good news from MOB….

https://x.com/nwsmobile/status/2107184041338306801?s=46&t=0ZvB_AF2VfA6c0SDxf53yA


.

Everywhere but KVAX is back for me!

[olafminesaw]

[NorthHillsWx]

GFS drives a cat 3 into into Pascagoula 

[MJO812]

[Windspeed]

Even on that GFS operational run, there is a very fine line between a sheared lopsided mess and a hurricane. I don't have a good feel for this one other than perhaps to say that despite the favorable jetstreak to ventilate the system NE off the ECONUS, strong mid-level flow could easily wreck the system's ability to remain vertically stacked. That setup could entrain stable airmass as well. Needless to say, that run has me scratching my head to see 957 mb so near to landfall. If nothing else, perhaps we end the hurricane drought. Also, I should add that this setup looks pretty dynamic to help with dought conditions across the southeast with trough placement over Texas, GOM feed, and ample lift remaining after landfall.

[hawkeye_wx]

The 18z hurricane models all strengthen this system to the 970s in the central gulf, but then shear and dry air rip it apart as it nears the gulf coast.

[NorthHillsWx]

Hurricane Nate from 2017 is a very similar system to what we have here from upper level setup over the gulf during the same time of year 

[Windspeed]

The 18z hurricane models all strengthen this system to the 970s in the central gulf, but then shear and dry air rip it apart as it nears the gulf coast.

The HAFS suites look very realistic as opposed to the overdone operational parent. An assymetric system. The strongest winds may be well in advance of the COC by the time it reaches the coast.

[WxWatcher007]

18z Euro is stronger than 12z (about 989mb at landfall), but the AI version is weak. 

I'm not sure I have a good handle on this one, either. A more northeasterly motion should align enough for some modest intensification, but much like Edouard, it's going to need time to coalesce. The ceiling is a hurricane, but I'm just not sure we get there. But we need a well defined low before hurricane models even get a good handle on things. 

[vortex95]

2 hours ago, WxWatcher007 said:

18z Euro is stronger than 12z (about 989mb at landfall), but the AI version is weak. 

I'm not sure I have a good handle on this one, either. A more northeasterly motion should align enough for some modest intensification, but much like Edouard, it's going to need time to coalesce. The ceiling is a hurricane, but I'm just not sure we get there. But we need a well defined low before hurricane models even get a good handle on things. 

Something doesn't seem right.  I was surprised the 18z ECWMF suddenly went the GFS route.

But the 700-300 mb RH fields and PWAT anoms tell the story. I attached 18z ECMWF 72, 105, and 114 hr 700-300 RH.

Even when it is still the Bay of Campeche, it is "halved" from a strong moisture gradient, and it just gets stronger w/ time. looking like a typical ET low development.  And look at the 114 hr fcst PWAT anomaly.  That clearly shows a frontal structure, and compare the PWAT anomalies to Simon in the EPAC.  That's not nearly the anomaly you'd see in a typical TC.

I can see NHC "playing games" here.  Calling it something that it is not b/c of non-meteorological factors (social media nonsense, its sensible wx impact, etc).  But ET low can and do form in the Gulf in Oct (see the 1992 case I posted about earlier) and given the strength of El Nino, it makes ET lows this early even more likely.  In fact, by 36 hr, the 250 mb STJ become quite apparent near the Gulf Coast, and in 5 days close to landfall, a strong 250 s/w is present in the region, obviously aiding in the system's development.

Some might go, "but the simulated IR from the GFS shows an eye!"  Well, it is the GFS, and yes, initially it could be a TS/STS but here lies another issue, transition to a PT/ET low when it is approaching a landfall.  Sandy anyone?  You see the problem here.  But I say, in the end, it is what it is, and call it as such.  Don't let external pressures and nonsense contaminate the met science!
 

[Boston Bulldog]

If Isaias ends up becoming a formidable cane, this would be a significant coup by DeepMind

[vortex95]

Also, here is the 18z SHIPS output for 92L,  The environmental shear is currently moderate and increases w/ time so it is 30 kt by 84 hr.
https://hurricanes.ral.ucar.edu/realtime/plots/northatlantic/2026/al922026/stext/26100518AL9226_ships.txt
 

[vortex95]

1 minute ago, Boston Bulldog said:

If Isaias ends up becoming a formidable cane, this would be a significant coup by DeepMind

From a strictly climo POV, yes, such a formation in the Bay of Campeche and intensification as a TC to the Gulf Coast happens often, but this climo is a weakness at times for AI models b/c not all follow climo or what would be more typical. 

[NorthHillsWx]

Hurricane models overwhelmingly favor intensification into a hurricane