Isaias, advisory 12

000
WTNT34 KNHC 091453
TCPAT4
 
BULLETIN
Hurricane Isaias Advisory Number  12
NWS National Hurricane Center Miami FL       AL092026
1000 AM CDT Fri Oct 09 2026
 
...CENTER OF ISAIAS EXPECTED TO REACH THE WESTERN FLORIDA PANHANDLE
COAST THIS EVENING...
...LIFE-THREATENING STORM SURGE AND DEVASTATING WINDS LIKELY ALONG 
THE FLORIDA PANHANDLE AND ALABAMA COASTS...
 
 
SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...27.7N 87.3W
ABOUT 195 MI...310 KM S OF PENSACOLA FLORIDA
ABOUT 145 MI...235 KM SE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...NNE OR 25 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...959 MB...28.32 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
None.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
 
A Storm Surge Warning is in effect for...
* Mouth of the Mississippi River to the Suwannee River
 
A Hurricane Warning is in effect for...
* Ocean Springs, MS to the Bay/Gulf County Line, FL
 
A Tropical Storm Warning is in effect for...
* Jefferson/Plaquemines Parish Line, LA to west of Ocean Springs, MS
* East of Bay/Gulf County Line to Aucilla River, FL
 
A Storm Surge Watch is in effect for...
* Suwannee River to Yankeetown, FL
 
A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline. For
a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.
 
A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.
 
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
 
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline. For a depiction of areas at risk, please see the
National Weather Service Storm Surge Watch/Warning Graphic,
available at hurricanes.gov.
 
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
 
 
DISCUSSION AND OUTLOOK
----------------------
At 1000 AM CDT (1500 UTC), the center of Hurricane Isaias was
located near latitude 27.7 North, longitude 87.3 West. Isaias is
moving toward the north-northeast near 16 mph (26 km/h). This 
motion is expected to continue through this evening, followed by a 
northward motion on Saturday. On the forecast track, Isaias is
expected to approach the U.S. northern Gulf Coast this afternoon and
make landfall within the warning area this evening.
 
Maximum sustained winds are near 120 mph (195 km/h) with higher 
gusts. Isaias is a category 3 hurricane on the Saffir-Simpson 
Hurricane Wind Scale. Fluctuations in intensity are possible through 
this afternoon, but Isaias is expected to be at or near major 
hurricane strength when it makes landfall this evening. Weakening is 
expected beginning tonight after Isaias makes landfall, and the 
storm is likely to become post-tropical by late Saturday.
 
Hurricane-force winds extend outward up to 35 miles (55 km) from the
center and tropical-storm-force winds extend outward up to 205 miles
(335 km).
 
The estimated minimum central pressure is 959 mb (28.32 inches).
 
 
HAZARDS AFFECTING LAND
----------------------
Key messages for Isaias can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC.
 
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...
 
AL/FL Border to Grayton Beach, FL...6-9 ft
Grayton Beach, FL to Indian Pass, FL...4-7 ft
Indian Pass, FL to Steinhatchee River, FL...4-6 ft
Dauphin Island, AL to AL/FL Border...4-6 ft
Steinhatchee River, FL to Suwannee River, FL...3-5 ft
Mouth of the Mississippi River, LA to Dauphin Island, AL...3-5 ft
Lower Mobile Bay...3-5 ft
Suwannee River, FL to Yankeetown, FL...2-4 ft
Upper Mobile Bay...2-4 ft
 
The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.
 
For a complete depiction of areas at risk of storm surge inundation,
please see the National Weather Service Peak Storm Surge Graphic,
available at hurricanes.gov/graphics_at4.shtml?peakSurge.
 
WIND: Hurricane conditions are expected within the Hurricane Warning
this evening into early Saturday, with tropical storm conditions
beginning during the next few hours. Hurricane force winds are
expected to spread inland as far as 100 miles from the
coast into southern Alabama. Tropical storm conditions are expected
in the warning areas beginning in the next few hours.
 
RAINFALL:  Through the weekend, Isaias is expected to produce 
rainfall amounts of 4 to 8 inches across southern Alabama, the 
Florida Panhandle and Big Bend, and southwest Georgia. Localized 
totals up to 15 inches are possible, particularly within banding 
across the Florida Panhandle and Big Bend. 

Across much of the remainder of the Southeast, rainfall amounts of 2 
to 5 inches are expected.  Localized higher amounts up to 10 inches 
are possible, especially across the Southern Appalachians and 
coastal Carolinas.  

Flash and urban flooding is possible across the region, with 
considerable impacts likely across much of southern Alabama and the 
Florida Panhandle into southwestern Georgia. River flooding is also 
expected, some of which could be significant. 

For a complete depiction of forecast rainfall associated with 
Isaias, please see the National Weather Service Storm Total Rainfall 
Graphic available at
hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk 
graphic at hurricanes.gov/graphics_at4.shtml?ero.
 
TORNADOES: A tornado risk will begin this afternoon and continue
tonight in coastal areas of Alabama, the Florida Panhandle, and
southern Georgia. The tornado threat will continue Saturday across
parts of eastern Alabama, the Florida Panhandle, Georgia, and the
Carolinas.
 
SURF: Swells from Isaias are affecting the western and northern
portions of the Yucatan Peninsula and are spreading northward toward
the Gulf Coast. These swells are likely to cause life-threatening
surf and rip current conditions. Please consult products from your
local weather office.
 
A depiction of rip current risk for the United States can be found
at: hurricanes.gov/graphics_at4.shtml?ripCurrents
 
 
NEXT ADVISORY
-------------
Next intermediate advisory at 100 PM CDT.
Next complete advisory at 400 PM CDT.
 
$$
Forecaster Berg
 

000
WTNT44 KNHC 091454
TCDAT4
 
Hurricane Isaias Discussion Number  12
NWS National Hurricane Center Miami FL       AL092026
1000 AM CDT Fri Oct 09 2026
 
An Air Force Reserve Hurricane Hunter aircraft currently 
investigating Isaias measured a peak 700-mb flight-level wind of 
120 kt within the eastern eyewall a few hours ago, prompting an 
upgrade of the hurricane to major hurricane status with estimated 
surface winds of 105 kt. Based on the last several dropsondes 
released in the eye, the central pressure appears to have leveled 
off around 959 mb. On the last pass through the eastern eyewall, 
just about a half hour ago, the plane measured a flight-level 
wind of 111 kt, suggesting that the peak winds may have also 
leveled off. The eye itself has become cloud filled in visible 
satellite imagery, but it is now moving into range of several 
WSR-88D radars along the northern Gulf coast.

Strong deep-layer shear has definitely increased as forecast, with 
various analyses now showing 30-40 kt out of the southwest. 
However, the shear vector is nearly aligned with the storm's 
motion, which limits its adverse effects, and upper-level 
divergence is also increasing over the hurricane. This setup has 
likely allowed the hurricane to intensify this morning, and the 
hurricane regional models (HAFS-A, HAFS-B, and HWRF), as well as 
the statistical-dynamical models (SHIPS and LGEM), all suggest that 
Isaias could maintain major hurricane intensity up until its 
landfall this evening. Therefore, the NHC official forecast depicts 
Isaias with 100-kt winds just offshore the western Florida 
Panhandle this evening. Weakening will occur after landfall, but 
sustained hurricane-force winds will likely occur near and along 
Isaias's track up to 100 miles inland from the coast into southern 
Alabama, and gusts to hurricane force could extend even farther 
north into central Alabama. Isaias is likely to lose its tropical 
characteristics by 36 hours when it is over northern Alabama.

Aircraft fixes indicate that Isaias has drifted a bit east of the 
previous forecast track. NHC's track forecast leans on the eastern 
side of the guidance envelope, closest to the latest HCCA and GDMI 
guidance, and implies a potential landfall along the extreme 
western Florida Panhandle coast this evening. After moving inland, 
the center of Isaias is expected to continue northward through 
Alabama, before turning northeastward over the Tennessee and Ohio 
Valleys (as a post-tropical remnant low) on Sunday.

Now that the eye has become visible in WSR-88D coastal radars, 
hourly Tropical Cyclone Updates will be issued beginning at 11 AM 
CDT (1600 UTC).

 
Key Messages:
 
1. A life-threatening storm surge is expected from the Mouth of the
Mississippi River to Suwannee, Florida. Residents under evacuation 
orders should leave immediately and follow advice from local 
officials. 
 
2. Extremely dangerous and 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 have a safe room to ride out the 
storm and prepare for long-duration power outages.
 
3. Damaging wind gusts are likely over a large portion of the 
southeastern United States from western and northern Georgia 
westward over much of central and northern Alabama, southern middle 
Tennessee, and Mississippi, especially in areas of higher terrain.
Residents should secure loose outdoor items, avoid driving 
high-profile vehicles, prepare for power outages, and be aware of 
the potential for falling trees.
 
4. Isaias will bring areas of heavy rainfall to the central U.S. 
Gulf coast and much of the Southeast through the weekend. 
Considerable flash and urban flooding, and significant river 
flooding, are possible.

5. The tornado potential will increase this afternoon and continue 
through tonight. The greatest risk will be east of the center, 
particularly across the Florida Panhandle into southern Georgia. 
This risk will continue spreading north-northeast across
parts of the Southeast on Saturday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/1500Z 27.7N  87.3W  105 KT 120 MPH
 12H  10/0000Z 29.7N  86.8W  100 KT 115 MPH
 24H  10/1200Z 32.1N  87.1W   55 KT  65 MPH...INLAND
 36H  11/0000Z 34.2N  87.2W   35 KT  40 MPH...POST-TROP/INLAND
 48H  11/1200Z 36.5N  85.0W   25 KT  30 MPH...POST-TROP/INLAND
 60H  12/0000Z 39.1N  81.0W   20 KT  25 MPH...POST-TROP/INLAND
 72H  12/1200Z...DISSIPATED
 
$$
Forecaster Berg