Isaias, advisory 11

000
WTNT34 KNHC 090857
TCPAT4
 
BULLETIN
Hurricane Isaias Advisory Number  11
NWS National Hurricane Center Miami FL       AL092026
400 AM CDT Fri Oct 09 2026
 
...ISAIAS STRENGTHENING...
...PREPARATIONS SHOULD BE RUSHED TO COMPLETION AS THE WEATHER WILL
GO DOWNHILL QUICKLY TODAY....
 
 
SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...26.4N 88.0W
ABOUT 370 MI...590 KM NNE OF PROGRESO MEXICO
ABOUT 200 MI...320 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 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,
during the next 36 hours in the indicated locations. 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, in this case within 24 hours.
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, in this case within 24
hours.
 
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours. 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 AM CDT (0900 UTC), the eye of Hurricane Isaias was located
near latitude 26.4 North, longitude 88.0 West. Isaias is moving
toward the north-northeast near 15 mph (24 km/h). A turn toward the
north is expected later today. On the forecast track, Isaias is
expected to approach the U.S. northern Gulf Coast this afternoon and
make landfall within the warning area tonight or early Saturday.
 
Air Force and NOAA Hurricane Hunter data indicate that the maximum
sustained winds have increased to near 110 mph (175 km/h) with
higher gusts. Isaias is likely to become a major hurricane this
morning. Slight weakening is expected before landfall, but it is
expected to remain a dangerous hurricane.
 
Hurricane-force winds extend outward up to 30 miles (45 km) from the
center and tropical-storm-force winds extend outward up to 185 miles
(295 km).
 
The estimated minimum central pressure is 963 mb (28.44 inches) 
based on Air Force dropsonde data.
 
 
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...
 
Dauphin Island, AL to Indian Pass, FL...5-7 ft
Indian Pass, FL to Steinhatchee River, FL...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
Mobile Bay...3-5 ft
Suwannee River, FL to Yankeetown, FL...2-4 ft
Yankeetown, FL to Egmont Key, FL...1-3 ft
Lake Pontchartrain...1-3 ft
Morgan City, LA to Mouth of the Mississippi River, LA...1-2 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
area tonight into early Saturday, with tropical storm conditions
beginning later today. 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 likely across the region, with
considerable impacts possible 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 late this afternoon and
continue tonight in coastal areas of Alabama, the Florida Panhandle,
and far southwest 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 will spread northward toward
the Gulf Coast later today. 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 AM CDT.
Next complete advisory at 1000 AM CDT.
 
$$
Forecaster Blake
 

000
WTNT44 KNHC 090858
TCDAT4
 
Hurricane Isaias Discussion Number  11
NWS National Hurricane Center Miami FL       AL092026
400 AM CDT Fri Oct 09 2026
 
Isaias has intensified overnight. NOAA and Air Force Reserve 
Hurricane Hunter data showed that the maximum flight-level winds 
have increased up to 107 kt, with a better-defined eye and a 
shrinking eyewall. These changes are also present on satellite 
imagery, with a more symmetric presentation along with a warming 
eye/cooling eyewall. The available data suggest a current intensity 
of 95 kt for this advisory.
 
Isaias will likely become a major hurricane soon with the improving 
satellite imagery, and it could continue to intensify for the next 
12 hours or so while it moves over very warm and deep water. 
However, a large increase in shear is anticipated before landfall, 
which will probably cause some weakening to occur. This is a tenuous 
spot because it would only take about a 6h delay in the onset of the 
shear to bring a stronger hurricane than expected onshore. The new 
forecast explicitly is a bit higher than the last one, but our best 
forecast at this time is for a high-end category 2 intensity at 
landfall, which is about the same as before.  Regardless of its 
exact wind speed at landfall, Isaias will be a dangerous hurricane 
with significant storm surge, damaging winds, and flooding rains. 
The wind field is also predicted to grow due to a trough 
interaction, and some of these impacts will extend well away from 
the center. After landfall, gusty winds are expected to reach well 
inland over portions of the southeastern United States.
 
Isaias has turned towards the north-northeast (020/13 kt), and
the hurricane is expected to turn northward and accelerate later
today due to increasing flow between an upper trough near the
northwestern Gulf Coast and a subtropical ridge extending across
the western Atlantic. Landfall is expected to occur within the
hurricane warning area Friday night or early Saturday.  The new
forecast is almost the same as before, very near the Google DeepMind
guidance, which has been very accurate for Isaias.
 
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 today. 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 through the weekend.
Considerable flash and urban flooding, along with significant river
flooding, will be possible.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0900Z 26.4N  88.0W   95 KT 110 MPH
 12H  09/1800Z 28.4N  87.3W  105 KT 120 MPH
 24H  10/0600Z 31.0N  87.1W   65 KT  75 MPH...INLAND
 36H  10/1800Z 33.5N  87.5W   35 KT  40 MPH...POST-TROP/INLAND
 48H  11/0600Z 35.5N  86.7W   25 KT  30 MPH...POST-TROP/INLAND
 60H  11/1800Z 38.2N  83.1W   15 KT  15 MPH...POST-TROP/INLAND
 72H  12/0600Z...DISSIPATED
 
$$
Forecaster Blake