Hurricane Isaias

[Nomz]

Recon found 990 extrapolated; I would guess 995 or so on the drop, based on the last two passes. 

EDIT: Drop was was 996 @ 23 kt = 994mb

[Araz07]

Large tower just went up over Isaias' center

[Tyler Penland]

Popping towers but definitely looks like its ingested some dry air over the past couple hours.

[yoda]

BULLETIN
Tropical Storm Isaias Advisory Number   5
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Wed Oct 07 2026
 
...ISAIAS QUICKLY INTENSIFYING, FORECAST TO BE A HURRICANE BY 
THURSDAY MORNING...
 
 
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...22.7N 92.9W
ABOUT 225 MI...365 KM WNW OF PROGRESO MEXICO
ABOUT 500 MI...805 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
None
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
 
A Storm Surge Watch is in effect for...
* Mouth of the Mississippi River to Yankeetown
 
A Hurricane Watch is in effect for...
* Bay St. Louis to Indian Pass
 
A Tropical Storm Watch is in effect for...
* Jefferson/Plaquemines Parish line to west of Bay St. Louis
* East of Indian Pass to Aucilla River

[yoda]

Tropical Storm Isaias Discussion Number   5
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Wed Oct 07 2026
 
Satellite and aircraft data show that Isaias continues to 
strengthen.  GOES-19 imagery indicates that a central dense overcast 
has formed, and the system has become more symmetric than this 
morning.  The peak NOAA Hurricane Hunter aircraft 700-mb winds 
were 61 kt, with the pressure dropping to 994 mb.  The initial 
intensity is set to 55 kt as a reflection of this data.
 
Isaias is basically on track, moving east-northeast at 7 kt. There 
is no change to the synoptic reasoning as a deepening trough along 
the northwestern Gulf Coast and a strengthening Atlantic subtropical 
ridge should cause the system to move faster to the northeast 
tomorrow and northward on Friday.  As long as the cyclone remains 
intact, it makes physical sense that the system will move on the 
faster and eastward side of the guidance due to the stronger shear 
Isaias should encounter near landfall.  Thus, the new forecast is 
adjusted slightly to the east, closer to the AI-based and 
corrected-consensus models.
 
NOAA radar data (P3-TDR) show that the system is experiencing some 
southwesterly shear, with tilt analyses displaying the mid-level 
circulation displaced 5-10 n mi to the northeast of the low-level 
center.  This structure seems sufficient for further intensification 
given a continuation of similar low or moderate shear and very warm 
SSTs in a very humid environment.  Models are fairly consistent 
about the shear increasing on Friday, but almost all guidance still 
shows a category 1 or 2 hurricane at landfall.  While the regional 
hurricane models have generally come down on the peak intensity this 
cycle, it is unknown whether this is the start of a real trend, and 
we would prefer to see more than one guidance cycle before making 
any adjustments.  The new forecast is close to the previous one, 
near the high side of the model suite.
 
Key Messages:
 
1. Isaias is expected to strengthen and be a strong hurricane when 
it approaches the northern Gulf Coast on Friday. There is an 
increasing risk of life-threatening storm surge along portions of 
the northern Gulf Coast, and a Storm Surge Watch is in effect from 
The Mouth of the Mississippi River to Yankeetown, Florida. Residents 
in the watch area should follow advice given by local officials and 
evacuate if told to do so.

2. The risk of damaging hurricane-force winds is increasing over 
portions of the Florida Panhandle, southern Alabama, and southern 
Mississippi.  A Hurricane Watch has been issued from Bay St. Louis, 
Mississippi, to Indian Pass, Florida.  Residents in these areas 
should prepare for the possibility of long-duration power outages. 

3. Isaias will bring areas of heavy rainfall to the central U.S. 
Gulf Coast and much of the Southeast Friday into the weekend. Flash 
and urban flooding, along with isolated river flooding, will be 
possible.

4. Isaias could bring gusty winds and areas of heavy rain to the 
western portion of the Yucatan Peninsula through Thursday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/2100Z 22.7N  92.9W   55 KT  65 MPH
 12H  08/0600Z 23.1N  91.8W   70 KT  80 MPH
 24H  08/1800Z 24.1N  90.1W   80 KT  90 MPH
 36H  09/0600Z 25.8N  88.7W   90 KT 105 MPH
 48H  09/1800Z 28.1N  87.6W   95 KT 110 MPH
 60H  10/0600Z 31.0N  87.3W   60 KT  70 MPH...INLAND
 72H  10/1800Z 34.0N  87.5W   30 KT  35 MPH...POST-TROP/INLAND
 96H  11/1800Z 37.5N  84.5W   15 KT  15 MPH...POST-TROP/INLAND
120H  12/1800Z...DISSIPATED
 
$$
Forecaster Blake

[Floydbuster]

 

[WxWatcher007]

Great tweet from Andy

[DeltaPilot]

Not the best looking symmetry there. Appears it may have a very small window for intensification, then it's going to struggle. OHC can only do so much. I'd say major status will be difficult at this point.

[olafminesaw]

47 minutes ago, WxWatcher007 said:

Great tweet from Andy

Yeah recon just found 988, so still fairly decent intensification which is quite impressive given how sheared it looks

Also a nice little core evident on microwave:

[WxWatcher007]

33 minutes ago, olafminesaw said:

Yeah recon just found 988, so still fairly decent intensification which is quite impressive given how sheared it looks

Also a nice little core evident on microwave:

Cyan ring there. That’s significant.

[dbullsfan]

Cyan ring there. That’s significant.

I think he takes off tonight.


.

[WxWatcher007]

On the cusp at 11pm

[WxWatcher007]

982mb dropsonde

[Shenanagins1091]

Great sunset in Gulf Shores AL tonight 

[Nomz]

Hurricane warnings hoisted for extreme W FL, AL, E MS.

[40/70 Benchmark]

1 hour ago, DeltaPilot said:

Not the best looking symmetry there. Appears it may have a very small window for intensification, then it's going to struggle. OHC can only do so much. I'd say major status will be difficult at this point.

Yea, I have it falling just short. 

[MattPetrulli]

 
Hurricane Isaias Tropical Cyclone Update
NWS National Hurricane Center Miami FL       AL092026
1030 PM CDT Wed Oct 07 2026

...ISAIAS BECOMES A HURRICANE...

Dropsonde data from an Air Force Reserve hurricane hunter aircraft 
indicates that Isaias has become a hurricane, with maximum sustained 
winds of 75 mph (120 km/h) with higher gusts. The minimum central 
pressure measured from another dropsonde launched in the eye was  
982 mb (29.00 inches). 
 
SUMMARY OF 1030 PM CDT...0330 UTC...INFORMATION
---------------------------------------------------
LOCATION...22.9N 91.9W
ABOUT 180 MI...290 KM NW OF PROGRESO MEXICO
ABOUT 460 MI...745 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES
 

[WxWatcher007]

Was just coming to post about the dropsondes. Let's see what the next pass looks like but that was a substantial drop in pressure between center fixes. 

[WxWatcher007]

Waiting on one more center pass before going to bed...

[WxWatcher007]

980.3mb extrapolated. Pressure falls continue. 

As the deep convection continues over the center we are probably on the cusp of significant intensification, even as you see some more hostile conditions on the western edge of the system. It's a race between this current intensification trend and when the conditions ultimately disrupt the center.   

[Boston Bulldog]

Isaias is already a bit lopsided to the east, but the center is secluded enough from both shear and dry air to continue to intensify. Maybe a small eye pops briefly, honestly the analog may be Sandy before Cuba landfall (at least in regards to a potent late season core surrounded by synoptic fuel).

Isaias will be getting ripped apart upon landfall, but it will gain significant strength before doing that. Also the jet streak equatorward entrance region is going to fuel baroclinicty over the SE US. Not to be slept on, the tornado threat on the right side is going to be significant.

Isaias will have a ton of energy to be conserved as it gets absorbed by the trough as landfall occurs, this will be an impactful event

[NorthHillsWx]

Winds catching up to the pressure falls. Wouldn’t surprise me if recon found a cat 2 this morning. RI since yesterday morning in spite of shear. 40 mph increase since this time yesterday. 

[SnowenOutThere]

45 minutes ago, NorthHillsWx said:

Winds catching up to the pressure falls. Wouldn’t surprise me if recon found a cat 2 this morning. RI since yesterday morning in spite of shear. 40 mph increase since this time yesterday. 

It’s ridiculous how almost every storm in the gulf seems to rapidly intensify now. 

[jm1220]

13 minutes ago, SnowenOutThere said:

It’s ridiculous how almost every storm in the gulf seems to rapidly intensify now. 

When you have jet fuel water temps unaffected by any other tropical system this year-yep that’s what happens. Luckily conditions should become significantly more hostile as it comes in. 

[olafminesaw]

HAFS A and B are predicting a decapitation at landfall

[CoastalWx]

Still a little disorganized on IR. Although, it seems to be fighting off shear a bit. 

[Interstate]

I see the Eastward motion help counteract the shear but as soon as it turn north, that is when you will start to see it get ripped apart. 

[Boston Bulldog]

24 minutes ago, olafminesaw said:

HAFS A and B are predicting a decapitation at landfall

Hah, impressive guillotine. The core will not be that well put together on approach, it also won’t be totally gone by landfall

[40/70 Benchmark]

35 minutes ago, Interstate said:

I see the Eastward motion help counteract the shear but as soon as it turn north, that is when you will start to see it get ripped apart. 

Yes, that is precisely what I was intimating in my write-up.

[jm1220]

1 hour ago, olafminesaw said:

HAFS A and B are predicting a decapitation at landfall

Wonder if you can even call that a halfacane, maybe thirdacane?