Isaias, advisory 13

000
WTNT34 KNHC 092052
TCPAT4
 
BULLETIN
Hurricane Isaias Advisory Number  13
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Fri Oct 09 2026
 
...CONDITIONS DETERIORATING QUICKLY WITHIN THE STORM SURGE AND
HURRICANE WARNING AREAS...
...RESIDENTS SHOULD BE SEEKING SAFE SHELTER...
 
 
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...29.2N 87.0W
ABOUT 90 MI...145 KM S OF PENSACOLA FLORIDA
ABOUT 125 MI...195 KM SSE OF MOBILE ALABAMA
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 17 MPH...28 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. 
 
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 400 PM CDT (2100 UTC), the center of Hurricane Isaias was located
near latitude 29.2 North, longitude 87.0 West. Isaias is moving
toward the north near 17 mph (28 km/h), and this general motion is 
expected to continue through Saturday. A north-northeastward to 
northeastward motion is forecast on Sunday. On the forecast track, 
Isaias is expected to make landfall along the coast of the western 
Florida Panhandle this evening. The center is then expected to move 
across Alabama and into the Tennessee Valley Saturday and Sunday.
 
Maximum sustained winds are near 115 mph (185 km/h) with higher
gusts.  Isaias is a category 3 hurricane on the Saffir-Simpson
Hurricane Wind Scale.  Little change in strength is expected before 
Isaias makes landfall this evening. Weakening is expected to begin 
tonight after landfall, and Isaias is forecast to become 
post-tropical on 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). A sustained wind of 46 mph (74 km/h) with a gust to 58 
mph (93 km/h) was recently measured at Fair Point Light 2 near Gulf 
Breeze, Florida. A wind gust to 56 mph (90 km/h) was reported at 
the Pensacola Naval Air Station.
 
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: Within the Hurricane Warning area, tropical storm conditions
are now occurring, and hurricane conditions are expected this
evening into early Saturday. Hurricane-force winds are expected to
spread inland as far as 100 miles from the coast into southern
Alabama. Tropical storm conditions are also occurring in the
tropical storm warning areas.
 
RAINFALL:  From Friday 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, urban, and river flooding is possible across the region, with 
considerable impacts likely across much of southern Alabama and the 
Florida Panhandle into southwestern Georgia. Considerable flash 
flooding and landslides are also possible across the Southern 
Appalachians. 

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: The risk for tornadoes this afternoon in the Florida 
Panhandle will continue into this evening and tonight across the 
Florida Panhandle, southeast Alabama, 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 much of the Gulf coasts of
the United States, Mexico, and western Cuba. 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 700 PM CDT.
Next complete advisory at 1000 PM CDT.
 
$$
Forecaster Berg
 

000
WTNT44 KNHC 092052
TCDAT4
 
Hurricane Isaias Discussion Number  13
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Fri Oct 09 2026
 
Deep-layer shear from the southwest has increased to 30-40 kt, and
the hurricane's structure is responding accordingly. WSR-88D radar
data shows that the structure is becoming increasingly asymmetric,
with very intense convection mainly confined to the northern
eyewall. Tail Doppler radar data from the NOAA P-3 has also shown
that the circulation is becoming tilted with height. That said,
some impressive winds were measured at flight-level--136 kt by the
Air Force Reserve at 10,000 feet and 126 kt by NOAA at 8,000 ft.
While these winds themselves would normally support a higher
intensity, several dropsondes released in the eyewall showed that
there is a sharp drop-off of winds at the ocean surface, with
layer-averaging suggesting a surface intensity of 90-95 kt. In
addition, recent Doppler radar data from Mobile show winds of
100-110 kt at about 10,000 feet in the northern eyewall. Combining
all this data together, the maximum surface winds appear to be
around 100 kt, although it's very likely that Isaias will be a
gustier-than-normal hurricane when it makes landfall.
 
Isaias has turned northward and is accelerating with a current
motion of 010/15 kt. The track guidance has honed in on a landfall
over the western Florida Panhandle near the Pensacola area sometime
this evening. A northward motion is expected to continue through
Saturday, bringing Isaias's center through Alabama, followed by a
northeastward trajectory across the Tennessee and the central
Appalachians on Sunday. The circulation is expected to dissipate by
hour 60.
 
The high-resolution hurricane regional models (HAFS-A, HAFS-B, and
HWRF), as well as the statistical-dynamical models (SHIPS and LGEM)
indicate that Isaias is likely to be at or near major hurricane
strength at landfall this evening. After landfall, fast weakening
is expected, with some caveats. As mentioned previously, Isaias is
likely to be a gusty hurricane, and its fast motion could bring
strong hurricane-force gusts well inland. Simulated satellite
imagery from global model guidance indicates that Isaias is likely
to transition to a post-tropical cyclone over Alabama by Saturday
afternoon, although it could still be producing
tropical-storm-force gusts, especially in areas of higher terrain.
 
 
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 and the
southern Appalachians, 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, along with significant river
flooding, will be possible. Landslides are also possible across the
Southern Appalachians.
 
5. The tornado potential will 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  09/2100Z 29.2N  87.0W  100 KT 115 MPH
 12H  10/0600Z 31.2N  86.8W   75 KT  85 MPH...INLAND
 24H  10/1800Z 33.4N  87.2W   40 KT  45 MPH...POST-TROP/INLAND
 36H  11/0600Z 35.6N  86.1W   30 KT  35 MPH...POST-TROP/INLAND
 48H  11/1800Z 38.1N  82.5W   25 KT  30 MPH...POST-TROP/INLAND
 60H  12/0600Z...DISSIPATED
 
$$
Forecaster Berg