Hurricane Isaias

[MANDA]

2 minutes ago, cardinalland said:

It appears the eye is starting to clear

Looking good with some nice ventilation going on even in the SW quadrent. Has about 24 hours to maximize itself before shear starts to really impinge.

[yoda]

BULLETIN
Hurricane Isaias Intermediate Advisory Number 8A
NWS National Hurricane Center Miami FL       AL092026
100 PM CDT Thu Oct 08 2026
 
...ISAIAS EXPECTED TO STRENGTHEN FURTHER...
...PREPARATIONS TO PROTECT LIFE AND PROPERTY FROM STORM SURGE AND
DAMAGING WINDS IN THE WARNING AREA SHOULD BE RUSHED TO COMPLETION
TODAY...
 
 
SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...24.0N 89.8W
ABOUT 185 MI...300 KM N OF PROGRESO MEXICO
ABOUT 355 MI...570 KM S OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H
PRESENT MOVEMENT...ENE OR 60 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...975 MB...28.80 INCHES

[beanskip]

Last recon pass is up 2 mb to 978mb. Never seen a strengthening storm that doesn't lose any pressure for 5 hours ...

[Boston Bulldog]

I don’t think that’s a legit eye, IR suggests that the inner core convection still isn’t organized enough yet to pop one. Pause in strengthening for now, let’s see if Isaias can get going again soon.

[cptcatz]

Looks like it's struggling. What else do you expect from #2026?

[Interstate]

1 minute ago, cptcatz said:

Looks like it's struggling. What else do you expect from #2026?

Yep I was going to say the same thing... It just cannot keep the convection going.... every time it gets a burst, it fizzles out.

[cardinalland]

It’s passing over some slightly cooler SSTs right now

[ROOSTA]

I don't see an "EYE". Just hallucinations with convection sheared well to the NE. 

I named this sat capture as GONZO 

[eyewall]

Cloud tops warmed pretty quick. This system is definitely struggling right now. 

[NorthHillsWx]

Been on the same pattern since yesterday of convection really dying off during diurnal minimum but coming back with a vengeance overnight 

[GaWx]

1 hour ago, cptcatz said:

Looks like it's struggling. What else do you expect from #2026?

That’s good news if it holds for those threatened. Hopefully shear will do its thing and keep it struggling. But it looks like it will probably still be a hurricane when it comes in and thus be no picnic for them.

[jm1220]

30 minutes ago, NorthHillsWx said:

Been on the same pattern since yesterday of convection really dying off during diurnal minimum but coming back with a vengeance overnight 

I would think tonight’s its last chance to ramp up. It’s clearly struggling already with dry air and shear. Looks elongated already. 

[NorthHillsWx]

1 hour ago, Boston Bulldog said:

I don’t think that’s a legit eye, IR suggests that the inner core convection still isn’t organized enough yet to pop one. Pause in strengthening for now, let’s see if Isaias can get going again soon.

Looks like a legit eye to me but it’s only cleared out bc the convection waned and isn’t overshooting it from the SW I believe. Looks legit now 

[NorthHillsWx]

Recon seems supportive of 80 kts, closing in on cat 2 at a much more modest rate today 

[olafminesaw]

14 minutes ago, NorthHillsWx said:

Recon seems supportive of 80 kts, closing in on cat 2 at a much more modest rate today 

I would expect one more significant ramp up tonight before it hits the shredder Tommorow 

[cptcatz]

Looks like it's trying to wrap some deep convection around the west side of the eye. If it can hold on and build an eyewall out of this, that's it's shot.

[NorthHillsWx]

20 minutes ago, olafminesaw said:

I would expect one more significant ramp up tonight before it hits the shredder Tommorow 

 

16 minutes ago, cptcatz said:

Looks like it's trying to wrap some deep convection around the west side of the eye. If it can hold on and build an eyewall out of this, that's it's shot.

Yep. Core is there and it will be moving over slightly warmer waters too. Diurnal max will be the max for this system. Imo 95-105 kts is attainable 

[vortex95]

On 10/6/2026 at 4:50 PM, NorthHillsWx said:

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 

Probably b/c of it small size.  Global models had trouble picking it up.

[nycwinter]

we ll know from past history these gulf storms intensify last day right up to landfall even in cases of strong wind shear..

[hawkeye_wx]

Models have been predicting a good drop in pressure tonight as the center passes over the warm loop current eddy.

[vortex95]

Isaias is an atypical TC situation esp. for a landfall. In a way it reminds me of Sandy in Oct 2012, but some differences.  However, it has similar implications.

 

The models, both global and hurricane, all along have showed very rapid weakening of Isaias the last 9-12 hr to landfall.

 

12z HAFS-A   09/18z 951 mb /110 kt

                    10/03z 984 mb / 63 kt

12z HAFS-B   09/18z 964 mb / 99 kt

                    10/03z 985 mb / 57 kt

 

So there is a serious question if it will be a hurricane at landfall.

 

In addition, looking at the storm structure forecast, it is difficult to imagine it will still be classifiable as a tropical cyclone at landfall.

 

The SHIPS shear value is 35 kt 09/12z increasing to 49 kt 10/00z.  It is fully embedded in a 250 jet streak near landfall and all the convection sheared off N of the center at the time.  Very dry air (<20% 700-300 RH) is completely wrapped around and over the center (HAFS A/B forecast attached) and clear, defined frontal features apparent on the moisture fields.

 

Since Isaias is rather small and not that strong, it is unlikely to be able to ward off wind shear and dry air intrusion, like Ian did in Sep 2022.

 

Despite all of the above, I do not see any real emphasis currently in the mainstream on this very real possibility.  I've seen this before from NHC.  They avoid much emphasis on rapid weakening close to landfall b/c they think ppl will not take the warnings as seriously, but I find this disingenuous.  They are not being objective and transparent.  This was apparent w/ Milton, which is the most rapid weakening for a HU in a short period leading up to a U.S. landfall.

 

Our forecast skill/modeling have come a long way for TCs, so confidence in outlier or atypical scenarios is higher these days and we should take full advantage of this operationally.

 

I know of no Gulf hurricane situation quite like this one where such rapid weakening and quick PT/ET transition occurs near landfall (Milton comes close).  And I see no reason why the HAFS weakening forecast would be wrong given the synoptic pattern currently and this model handled the very rapid weakening of Milton.  That was a strong baroclinic interaction with high shear impacting the hurricane.

 

So this presents a problem/challenge as to how Isaias could be handled.  The concern is that in deference to messaging, it may not be called PT/ET at landfall or below hurricane strength even if it clearly is since within 12 hr of landfall it may be much stronger.

 

From an objective meteorological standpoint?  It should not matter where a TC is (close to a landfall or far at sea), how strong it is, or what type of watches/warnings are in effect, it should be treated "as is" operationally.  So if goes ET/PT just before landfall, call it for what is it.  The atmosphere does not care about our subjective policies/rules, it does what it does. There is nothing that says a TC can not go ET/PT just before landfall, and it has been done before (Sandy).  And after Sandy, things were adjusted so tropical watches/warnings remain in place even if a TC goes ET/PT, so things are covered here from a messaging standpoint.
 

This kind of objectivity is important to the meteorological science.  A hurricane at landfall or not is significant from a climo standpoint.  And in some cases depending on the state, county, or city/town, what something is called/labeled makes a difference from an insurance and legal standpoint.

 

Some may say all what I say above is being pedantic or picayune, but I beg differ.  There were significant discussions and controversy in the meteorological and other fields as to what Sandy was called at landfall.  I am just proactively pointing out beforehand a similar TC situation currently.

 

[Interstate]

I find 100MPH hard to believe with the way it looks right now.

[yoda]

BULLETIN
Hurricane Isaias Advisory Number   9
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Thu Oct 08 2026
 
...HURRICANE HUNTERS FIND THAT ISAIAS NOW HAS 100 MPH WINDS...
...PREPARATIONS TO PROTECT LIFE AND PROPERTY FROM STORM SURGE AND
DAMAGING WINDS IN THE WARNING AREA SHOULD BE RUSHED TO COMPLETION
TODAY...
 
 
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...24.4N 89.3W
ABOUT 215 MI...345 KM N OF PROGRESO MEXICO
ABOUT 325 MI...525 KM S OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H
PRESENT MOVEMENT...NE OR 50 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...975 MB...28.80 INCHES

[yoda]

Hurricane Isaias Discussion Number   9
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Thu Oct 08 2026
 
The eye of Isaias has become apparent on visible and infrared
satellite imagery.  Interestingly, this is the first eye noted on
satellite pictures in the Atlantic basin during the 2026 Hurricane
Season.  The cloud tops have mostly warmed in the system, but the
latest subjective Dvorak classification value from TAFB has
increased to T4.5 or 77 kt.  NOAA Hurricane Hunter aircraft
observations do not indicate a drop in central pressure so far and
the peak 700-mb flight-level winds have not increased.  However,
Tail Doppler Radar wind velocities from the aircraft measured just
above the surface support increasing the intensity to 85 kt for
this advisory.
 
Satellite and aircraft center fixes indicate that the hurricane 
appears to have made its expected turn toward the northeast and the 
initial motion is now 050/10 kt.  Isaias is expected to turn 
northward tomorrow and move between a mid-level ridge extending 
westward from the Bahamas to the Florida peninsula and a trough 
near the northwest Gulf Coast.  On the forecast track, the center 
will move inland along the northern Gulf coast within the next 36 
hours, and then pass over portions of the southeastern U.S. during 
the next few days.  The official forecast is nudged slightly 
eastward and follows the latest corrected consensus model guidance. 
 
The intensity forecast remains somewhat problematic.  The hurricane 
will be passing over Gulf waters of high oceanic heat content 
during the next day or so.  In fact, the projected track of Isais 
shows it passing near a warm eddy overnight.  However, the vertical 
wind shear, which is already significant, is expected to increase 
substantially during the next 36 hours. The current thinking is that 
the shear will not offset the conducive oceanic conditions until 
12-24 hours, so further strengthening is anticipated overnight.  The 
official intensity forecast is at the high end of the model 
guidance, but in consideration of the expected stronger wind shear 
in 24-36 hours, some decrease in intensity is indicated as Isaias 
approaches the coast.  Regardless, Isaias is expected to remain a 
dangerous hurricane through landfall, and strong gusty winds are 
expected well inland after the center crosses the coast.

Key Messages:
 
1. A life-threatening storm surge is expected from the Mouth of the
Mississippi River to Suwannee, Florida. Residents in the warning
area should follow advice given by local officials and evacuate
immediately if told to do so.
 
2. Damaging hurricane force-winds are expected over portions of the
Florida Panhandle, southern Alabama, and southern Mississippi where
a Hurricane Warning is in effect. Residents in these areas should
prepare for the possibility of long-duration power outages.
 
3. Damaging wind gusts are possible over much of central and 
northern Alabama, extreme eastern Mississippi, and portions of 
western and northern Georgia, especially in areas of higher terrain. 
 Additional Tropical Storm and High Wind Watches and Warnings may be 
required for portions of that area later tonight. Residents should 
secure loose outdoor items, avoid driving high-profile vehicles, and 
prepare for power outages.

4. Isaias will bring areas of heavy rainfall to the central U.S.
Gulf coast and much of the Southeast Friday into the weekend.
Considerable flash and urban flooding, along with significant river
flooding, will be possible.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/2100Z 24.4N  89.3W   85 KT 100 MPH
 12H  09/0600Z 25.7N  88.4W   95 KT 110 MPH
 24H  09/1800Z 28.2N  87.4W   85 KT 100 MPH
 36H  10/0600Z 31.0N  87.2W   65 KT  75 MPH...INLAND
 48H  10/1800Z 33.2N  87.8W   30 KT  35 MPH...INLAND
 60H  11/0600Z 35.0N  87.8W   25 KT  30 MPH...POST-TROP/INLAND
 72H  11/1800Z 37.0N  85.0W   20 KT  25 MPH...POST-TROP/INLAND
 96H  12/1800Z...DISSIPATED
 
$$
Forecaster Pasch

[cardinalland]

Eye has continued to develop and clear.

 

Looks like a Cat 1-2 hurricane, which is what it is

[NorthHillsWx]

1 minute ago, cardinalland said:

Eye has continued to develop and clear.

 

Looks like a Cat 1-2 hurricane, which is what it is

Not a bad looking storm at all!

[Radtechwxman]

I was not expecting 100 mph at this advisory especially with little to no change in pressure. Isaias is looking better on satellite now. Tonight probably best chance to overperform with that warm eddy and diurnal favorable timing for intensification before shear starts to offset everything. 

[TriPol]

As I said, it'll hit Cat 3 before landfall.

[vortex95]

7 minutes ago, hawkeye_wx said:

Models have been predicting a good drop in pressure tonight as the center passes over the warm loop current eddy.

This happened w/ HU Lili in Oct 2002.  It ramped up very quickly over the loop current, but once exiting, it weakened even faster in short order.
 

90 > 125 kt in 24 hr and then 125 > 80 kt in 24 hr at landfall.  And the environment for LIli was not nearly as baroclinic w/ a lot of dry air/shear present as Isaias now.

20021002, 0000,  , HU, 23.0N,  85.7W,  90,  967, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021002, 0600,  , HU, 23.6N,  87.2W, 100,  962, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021002, 1200,  , HU, 24.4N,  88.3W, 110,  952, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021002, 1800,  , HU, 25.4N,  89.5W, 120,  941, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021002, 2013, I, HU, 25.9N,  89.9W, 125,  938, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021003, 0000,  , HU, 26.7N,  90.3W, 125,  940, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021003, 0600,  , HU, 28.1N,  91.4W, 105,  957, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021003, 1200,  , HU, 29.2N,  92.1W,  80,  962, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999
20021003, 1300, L, HU, 29.5N,  92.2W,  80,  963, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999,   10

[cptcatz]

I feel like asking NHC if those 100 mph winds are in the room with them right now...