Major Hurricane Isaias

[NorthHillsWx]

This system has escalated quite a bit from what the original thinking was. Definitely some potential for a strong hurricane especially in the middle of the gulf 

[WxWatcher007]

Now that we do have a well defined center and recon data that will be incorporated into the models, we should hopefully start to see gradual consensus on the eventual track and intensity. I'm still a touch skeptical, but far less so than yesterday given how much more compact this tends to be. These BoC systems can really produce.

Just goes to show how even in an otherwise historically inactive season things can change quickly. 

[Windspeed]

This system has escalated quite a bit from what the original thinking was. Definitely some potential for a strong hurricane especially in the middle of the gulf 

Having a closed surface circulation and its approximate location should give the TC models a better handle on environmental interaction. We'll have to see if there is RI potential prior to conditions becoming less favorable. I suppose there does exist the possibility of rapid intensification occurring, leading to some panic, only for the TC to rapidly weaken prior to landfall. It is an annoying forecast in that regard and subject to big changes quickly. It's tough to approximate exactly when strong mid-level shear will impede or disrupt a core, especially if the system intensifies faster than forecast. But no TC is going to be immune to 30+ kts of shear prior to landfall. Yet, before that shear escalates, the system will have very strong ventilation. Therefore, the ceiling is high through the first 72 hours. How close does the core get to the coast prior to shear obliterating it? Not like this would be the first time we've been psyched out by a hurricane in the GOM, of course.

[cardinalland]

It’s supposed to pass right over the loop current. And the tail end of a trough is often quite favorable. There’s a lot of moving pieces but a hurricane landfall looks plausible at the moment.

[Windspeed]

It’s supposed to pass right over the loop current. And the tail end of a trough is often quite favorable. There’s a lot of moving pieces but a hurricane landfall looks plausible at the moment.

The forecast track and storm motion keeps the center over relatively deep heat content. Obviously, shallow SSTs remain quite high and untapped due to limited frontal progression and miniscule TC activity so far this season. The system will not be a slow mover, so we must depend on the timing of development and changes in atmospheric conditions: How fast does the TC intensify versus how fast favorable atmospheric conditions deteriorate to hostile? The key limiting factors up to landfall are increasing mid-level shear and potential dry air encroachment to limit or weaken landfall intensity.

[olafminesaw]

And the GFS has folded like a house of cards

 

[NorthHillsWx]

Man, it looks really good on satellite right now. It’s got that look…

[40/70 Benchmark]

17 minutes ago, Windspeed said:

41 minutes ago, cardinalland said:

It’s supposed to pass right over the loop current. And the tail end of a trough is often quite favorable. There’s a lot of moving pieces but a hurricane landfall looks plausible at the moment.

The forecast track and storm motion keeps the center over relatively deep heat content. Obviously, shallow SSTs remain quite high and untapped due to limited frontal progression and miniscule TC activity so far this season. The system will not be a slow mover, so we must depend on the timing of development and changes in atmospheric conditions: How fast does the TC intensify versus how fast favorable atmospheric conditions deteriorate to hostile? The key limiting factors up to landfall are increasing mid-level shear and potential dry air encroachment to limit or weaken landfall intensity.

Looks like minimal cane landfall given just a cursory glance at things...if it looks a bit more compelling tomorrow I may write it up.

[TriPol]

I think this gets up to a major before it gets closer to the coast. The gulf has so much heat in it... just jet fuel for it. And if it slows down at all? 

[Windspeed]

I think this gets up to a major before it gets closer to the coast. The gulf has so much heat in it... just jet fuel for it. And if it slows down at all? 

Right now is the slowest motion we will see. The westerly steering flow in interaction with the mid-to-upper trough will push the TC towards the east and then begin to turn it poleward. At that point, it should be gaining forward motion into landfall.

[cardinalland]

Look at all those hot towers

 

Would agree on a C1 landfall being most likely right now. Reaching C3+ over the open ocean beforehand looks very attainable.

[NorthHillsWx]

I’m not going to over analyze individual model runs but if it takes a track like the GFS shows that’s really bad for surge at the mouth of the Mississippi, bay St. Louis, biloxi bay, and possibly mobile bay. Landfall intensity is important but if this peaks maybe 6-8 hours before landfall any weakening would not affect surge potential at all. That’s a very bad track in that regard

[Floydbuster]

Even if it weakens, the intensity offshore could have huge implications on potential storm surge.

[olafminesaw]

[Windspeed]

The first runs of the HAFS suites since classification are not impressive, to say the least. The TC gets walloped around 70'ish hours out and becomes very assymetric with advected dry air doing its thing. Something to keep in mind. Is the window there for a strong hurricane? Sure. But the TC needs to come together rapidly over the next 48 hours.

[40/70 Benchmark]

1 hour ago, Floydbuster said:

Even if it weakens, the intensity offshore could have huge implications on potential storm surge.

Yea, should be more a hydro concern than a wind issue....strikes me as a system that will be weakening well before landfall.

[40/70 Benchmark]

Anyone have latest links for Tomer Burg super ensemble and TCHP maps? Been away during the CONUS tropical respite over the past couple of years and some of my links seem to no longer be valid....Tomer seems like he is moving his stuff around.

Found this one for TCHP, but don't love it.

https://cwcgom.aoml.noaa.gov/cgom/OceanViewer/index_phod.html#

This was my go-to, hasn't been updated for a couple of years.

https://www.aoml.noaa.gov/phod/goos/gliders/images/tchp_conditions_latest.png

[Windspeed]

Anyone have latest links for Tomer Burg super ensemble and TCHP maps? Been away during the CONUS tropical respite over the past couple of years and some of my links seem to no longer be valid....Tomer seems like he is moving his stuff around.
Found this one for TCHP, but don't love it.
https://cwcgom.aoml.noaa.gov/cgom/OceanViewer/index_phod.html#
This was my go-to, hasn't been updated for a couple of years.

https://www.aoml.noaa.gov/phod/goos/gliders/images/tchp_conditions_latest.png

https://isotherm.rsmas.miami.edu/heat/weba/atlantic.php for updated TCHP maps. Sadly, many of the old NCEP and CPC sites are MIA these days for oceanic and atmospheric data.

[Newman]

55 minutes ago, 40/70 Benchmark said:

Anyone have latest links for Tomer Burg super ensemble and TCHP maps? Been away during the CONUS tropical respite over the past couple of years and some of my links seem to no longer be valid....Tomer seems like he is moving his stuff around.

Found this one for TCHP, but don't love it.

https://cwcgom.aoml.noaa.gov/cgom/OceanViewer/index_phod.html#

This was my go-to, hasn't been updated for a couple of years.

https://www.aoml.noaa.gov/phod/goos/gliders/images/tchp_conditions_latest.png

Tomer's newest tropics site

https://polarwx.com/tropical/

[40/70 Benchmark]

2 minutes ago, Newman said:

Tomer's newest tropics site

https://polarwx.com/tropical/

Yea, I found that, but not the super ensemble plot...his data seems to be in flux as he is in the process of moving to that site.

[40/70 Benchmark]

45 minutes ago, Windspeed said:

https://isotherm.rsmas.miami.edu/heat/weba/atlantic.php for updated TCHP maps. Sadly, many of the old NCEP and CPC sites are MIA these days for oceanic and atmospheric data.

Thanks.

Yea, this admin. has killed funding for data......it's why we lost N/CAR1 and the monthly QBO tabular data is no longer updated.

[Boston Bulldog]

Looking pretty dang organized for a TD on the latest microwave pass

 

[WxWatcher007]

Tropical Depression Nine Discussion Number   2
NWS National Hurricane Center Miami FL       AL092026
1000 PM CDT Tue Oct 06 2026
 
The convective organization of the depression has not changed much 
since the prior advisory. Much of the associated deep convection is 
displaced slightly to the north of the estimated surface center, but 
recently a new convective burst has emerged closer to this location. 
The initial intensity is held at 30 kt for now, consistent with the 
latest T2.0 Dvorak classification from TAFB. An ASCAT-C pass is 
expected to arrive shortly after this advisory issuance and will be 
helpful in reassessing the position and intensity of the system.

The depression is moving slowly eastward (080/4 kt) within weak 
steering currents to the south of an upper trough over the 
southeastern United States. The track models are in good agreement 
that the system should move eastward to east-northeastward through 
Thursday while passing to the north of the Yucatan Peninsula. While 
the center is forecast to remain well offshore, its passage will 
likely produce gusty winds and heavy rainfall for portions of the 
Yucatan Peninsula. A turn toward the northeast and north is 
predicted by Friday as the system moves within the flow between a 
shortwave trough over Texas and a strengthening ridge over the 
western Atlantic. There remains significant along- and cross-track 
spread in the track guidance regarding this northward turn, with the 
AI-based models on the right side of the envelope and generally 
faster than the physics-based guidance. The updated NHC forecast is 
slower than the previous one from 48-96 h to bring it closer to the 
latest corrected consensus (HCCA), but remains on the fast and right 
side of the latest models. Users should closely monitor forecast 
updates given the below-average confidence in this forecast.

High oceanic heat content, moist mid-levels, and upper-level 
divergence should allow the compact system to intensify during the 
next few days. The only limiting factor appears to be southwesterly 
vertical wind shear, which is forecast to strengthen later this week 
as the system approaches the northern Gulf Coast. Most skillful 
models show the system becoming a hurricane over the central Gulf, 
and the latest forecast shows a similar rate of intensification and 
peak intensity as the prior forecast, generally following the more 
aggressive Google DeepMind and HCCA aids. Due to strong shear, it is 
likely that the system peaks in strength before reaching the coast 
as a hurricane. The cyclone is also expected to grow in size as it 
approaches the northern Gulf Coast, and the anticipated convective 
and motion asymmetries will likely cause rain and wind impacts to 
extend far from the center on the eastern side of the storm.

 
Key Messages:
 
1. There is an increasing risk of dangerous wind and storm surge
impacts along portions of the northern Gulf Coast, and watches could
be required on Wednesday. Residents from Louisiana to the Florida
Panhandle should closely monitor the latest forecast updates and
ensure they have their hurricane plan in place.
 
2. The system will bring areas of heavy rainfall to the central U.S. 
Gulf coast Friday into the weekend. Flash and urban flooding, along 
with isolated river flooding, will be possible.
 
3. Yucatan Peninsula of Mexico: The depression is expected to
strengthen and could bring gusty winds and areas of heavy rain to
the western portion of the Yucatan Peninsula in a couple of days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0300Z 22.1N  95.0W   30 KT  35 MPH
 12H  07/1200Z 22.2N  94.2W   40 KT  45 MPH
 24H  08/0000Z 22.5N  92.7W   50 KT  60 MPH
 36H  08/1200Z 23.2N  91.1W   60 KT  70 MPH
 48H  09/0000Z 24.3N  89.7W   75 KT  85 MPH
 60H  09/1200Z 26.1N  88.7W   85 KT 100 MPH
 72H  10/0000Z 28.8N  88.3W   85 KT 100 MPH
 96H  11/0000Z 34.1N  88.8W   30 KT  35 MPH...INLAND
120H  12/0000Z 39.0N  86.0W   20 KT  25 MPH...POST-TROP/INLAND
 
$$
Forecaster Reinhart

[Boston Bulldog]

Remains a TD at 11pm, but the discussion makes it sound like they may upgrade to TS shortly once this ASCAT pass comes in

[Windspeed]

Intense bursting of convection now over the NHC's 10PM CDT advisory position:

[GaWx]

The 0Z UKMET landfalls at Mobile at 987 mb ~4AM CDT Sat, which is weaker than its lowest SLP of 978 mb 12 hours earlier in the N Gulf. The center then moves N over W AL before turning left into EC MS and then NE MS. Beneficial rains fall over much of the SE.

[Windspeed]

00z HAFS suites are significantly stronger versus 18z. Intensification is faster, with a major hurricane down into the 940s passing east of the mouth of the Mississippi River. Both still show disruption from increasing shear by landfall, but obviously, this would be troubling for surge impacts along the Mississippi, Alabama, and western Panhandle coastline.

[GaWx]

0Z Euro has landfall near Biloxi ~8AM CDT Sat at 986 mb.

[Windspeed]

Best track is now 35 kts and upgraded to TS Isaias for the next advisory package.

[dbullsfan]

I don't see how this is still a TD, gotta get bumped up