Tropical Storm Idalia Discussion Number 8
NWS National Hurricane Center Miami FL AL102023
1000 AM CDT Mon Aug 28 2023

The satellite presentation of the storm has improved this morning
with the center more deeply embedded within the deep convection and
colder cloud tops. However, recent reconnaissance aircraft data
from both the U.S. Air Force Reserve and NOAA indicate that the
improved satellite presentation has not yet resulted in an
increase in wind speed. The Air Force Hurricane Hunter aircraft
has measured peak 850-mb flight-level winds of 68 kt, and a minimum
pressure around 990 mb. Based on these data, the initial intensity
remains 55 kt this advisory. The Air Force aircraft will be in the
storm environment through early afternoon and that data should
continue to provide information Idalia's structure and intensity.

Recent satellite and aircraft fixes show that Idalia is moving
northward or 360/8 kt. A mid-level trough over the central
Gulf of Mexico and a ridge near the Greater Antilles should cause
Idalia to move northward at a faster forward speed during the next
12-24 hours. After that time, an even faster north-northeast
motion is expected an another mid-level trough moves across the
central and eastern portions of the United States. The latest NHC
track forecast is again quite similar to the previous forecast.
Although the track forecast has been quite consistent, there is
still some spread in the guidance by 48 hours, and it cannot be
emphasized enough that only a small deviation in the track could
cause a significant change in Idalia's landfall location in Florida
due to the paralleling track to the west coast of the state.

Although there is still some moderate northwesterly over the storm,
intensification seems likely during the next 12-18 hours, and
Idalia is forecast to become a hurricane during that time. By
Tuesday, the environment over the eastern Gulf of Mexico is
expected to become more conducive for strengthening. Steady to
rapid intensification is predicted beginning Tuesday while Idalia
traverses the warm waters of the eastern Gulf and the upper-level
environment becomes more favorable. The NHC intensity forecast
again calls for Idalia to reach major hurricane strength before
landfall along the Gulf coast of Florida.

This forecast has necessitated the issuance of Storm Surge and
Hurricane Warnings for portions of the west coast of Florida and
Storm Surge and Tropical Storm Watches for portions of the Atlantic
coasts of Florida and Georgia.

KEY MESSAGES:

1. There is a danger of life-threatening storm surge inundation
along portions of the Florida Gulf Coast where a Storm Surge Warning
is in effect, including Tampa Bay and the Big Bend region of
Florida. Inundation of 7 to 11 feet above ground level is expected
somewhere between Chassahowitzka and Aucilla River. Residents in
these areas should follow any advice given by local officials.

2. Hurricane conditions are expected within portions of the
Hurricane Warning area along the Florida Gulf Coast, with the
potential for destructive winds where the core of Idalia moves
onshore. Strong winds will also spread inland across portions of
northern Florida near the track of the center of Idalia.

3. Areas of flash and urban flooding, some of which may be locally
significant, are expected across portions of the west coast of
Florida, the Florida Panhandle, and southern Georgia Tuesday into
Wednesday, spreading into portions of the eastern Carolinas
Wednesday into Thursday.

4. Hurricane-force winds are expected across portions of far western
Cuba later today. Heavy rainfall is also expected across portions
of western Cuba and may produce areas of flash and urban
flooding as well as landslides across western Cuba.

FORECAST POSITIONS AND MAX WINDS

INIT 28/1500Z 20.8N 85.2W 55 KT 65 MPH
12H 29/0000Z 22.0N 85.2W 65 KT 75 MPH
24H 29/1200Z 23.9N 85.1W 75 KT 85 MPH
36H 30/0000Z 26.4N 84.6W 90 KT 105 MPH
48H 30/1200Z 29.2N 83.5W 100 KT 115 MPH
60H 31/0000Z 31.9N 81.2W 55 KT 65 MPH...INLAND
72H 31/1200Z 33.6N 78.0W 50 KT 60 MPH...OVER WATER
96H 01/1200Z 34.6N 71.2W 50 KT 60 MPH
120H 02/1200Z 34.5N 67.0W 50 KT 60 MPH

$$
Forecaster Brown

BULLETIN
Tropical Storm Idalia Advisory Number 8...Corrected
NWS National Hurricane Center Miami FL AL102023
1000 AM CDT Mon Aug 28 2023

Corrected Hurricane Warning end point in the change section of the
watches and warnings

...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR PORTIONS OF THE
WEST COAST OF FLORIDA...
...LIFE-THREATENING STORM SURGE AND DANGEROUS WINDS BECOMING
INCREASINGLY LIKELY FOR PORTIONS OF FLORIDA...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.8N 85.2W
ABOUT 80 MI...125 KM SSW OF THE WESTERN TIP OF CUBA
ABOUT 305 MI...495 KM SSW OF THE DRY TORTUGAS
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...990 MB...29.24 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Storm Surge Warning has been issued from Englewood northward to
the Ochlockonee River, including Tampa Bay.

A Hurricane Warning has been issued from the Middle of Longboat Key
northward to the Ochlockonee River, including Tampa Bay.

A Tropical Storm Warning has been issued from Chokoloskee northward
to the Middle of Longboat Key, and from west of the Lockheed
River westward to Indian Pass.

A Storm Surge Watch has been issued from Mouth of the St. Mary's
River to Altamaha Sound, Georgia.

A Tropical Storm Watch has been issued for the Atlantic coast of
Florida and Georgia from Sebastian Inlet, Florida northward to
Altamaha Sound, Georgia.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Englewood northward to the Ochlockonee River, including Tampa Bay

A Hurricane Warning is in effect for...
* Cuban province of Pinar del Rio
* Middle of Longboat Key northward to the Ochlockonee River,
including Tampa Bay

A Tropical Storm Warning is in effect for...
* Yucatan Peninsula from Tulum to Rio Lagartos, including Cozumel
* Isle of Youth Cuba
* Dry Tortugas Florida
* Chokoloskee northward to the Middle of Longboat Key
* West of the Ochlockonee River westward to Indian Pass

A Storm Surge Watch is in effect for...
* Chokoloskee northward to Englewood, including Charlotte Harbour
* Ochlockonee River to Indian Pass Florida
* Mouth of the St. Mary's River to Altamaha Sound Georgia

A Hurricane Watch is in effect for...
* Englewood to the Middle of Longboat Key
* West of the Ochlockonee River westward to Indian Pass

A Tropical Storm Warning is in effect for...
* South of the Middle of Longboat Key to Chokoloskee Florida
* West of the Ochlockonee River westward to Indian Pass

A Tropical Storm Watch is in effect for...
* Lower Florida Keys west of the west end of the Seven Mile Bridge
* Sebastian Inlet Florida northward to Altamaha Sound Georgia

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued 36
hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous. Preparations to protect life
and property should be rushed to completion.A Hurricane Warning
means that hurricane conditions are expected somewhere within the
warning area, in this case within the next 12-24 hours.
Preparations to protect life and property should be rushed to
completion.

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.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests along the southeastern U.S. coast should monitor the
progress of this system. Additional watches and warnings will
likely be required later today.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1000 AM CDT (1500 UTC), the center of Tropical Storm Idalia was
located near latitude 20.8 North, longitude 85.2 West. Idalia is
moving toward the north near 8 mph (13 km/h). A northward motion
is expected through tonight, followed by a faster north-northeast
motion on Tuesday and Wednesday. On the forecast track, the center
of Idalia is forecast to pass near or over western Cuba tonight,
over the extreme southeastern Gulf of Mexico by early Tuesday, and
reach the Gulf coast of Florida on Wednesday.

Maximum sustained winds are near 65 mph (100 km/h) with higher
gusts. Idalia is forecast to become a hurricane later today and a
dangerous major hurricane over the northeastern Gulf of Mexico by
early Wednesday.

Tropical-storm-force winds extend outward up to 105 miles (165 km)
from the center.

The latest minimum central pressure estimated from data from an Air
Force Reserve reconnaissance aircraft is 990 mb (29.24 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Idalia can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC,
and on the web at hurricanes.gov/text/MIATCDAT5.shtml

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...

Aucilla River, FL to Chassahowitzka, FL...7-11 ft
Chassahowitzka, FL to Anclote River, FL...6-9 ft
Ochlockonee River, FL to Aucilla River, FL...4-7 ft
Anclote River, FL to Middle of Longboat Key, FL...4-7 ft
Tampa Bay...4-7 ft
Middle of Longboat Key, FL to Englewood, FL...3-5 ft
Englewood, FL to Chokoloskee, FL...2-4 ft
Charlotte Harbor...2-4 ft
Indian Pass, FL to Ochlockonee River, FL...2-4 ft
Mouth of the St. Mary's River to Altamaha Sound, GA...2-4 ft
Chokoloskee, FL to East Cape Sable, FL...1-3 ft
Flagler/Volusia County Line, FL to Mouth of the St. Mary's
River...1-3 ft
Florida Keys...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.

Storm surge will raise water levels by as much as 4 to 6 feet above
normal tide levels along the southern coast of Pinar del Rio, Cuba.
Near the coast, the surge will be accompanied by large waves.

WIND: Hurricane conditions are expected within the hurricane
warning area in western Cuba later today. Winds are expected to
first reach tropical storm strength by this morning, making
outside preparations difficult or dangerous. Preparations to
protect life and property should be rushed to completion.

Tropical storm conditions are expected over portions of the
tropical storm warning area over the Yucatan Peninsula and the Isle
of Youth in Cuba through today

Hurricane conditions are expected within the hurricane warning area
in Florida by late Tuesday or Wednesday, with tropical storm
conditions beginning on Tuesday.

Tropical storm conditions are expected in the Dry Tortugas
beginning late today and within the tropical storm warning area
along the Florida Gulf coast on Tuesday.

RAINFALL: Idalia is expected to produce the following rainfall
amounts:

Portions of the eastern Yucatan: Additional 1 to 2 inches.

Western Cuba: 4 to 7 inches, with isolated higher totals of 10
inches.

Portions of the west coast of Florida, the Florida Panhandle,
southeast Georgia and the eastern Carolinas: 4 to 8 inches from
Tuesday into Thursday. Isolated higher totals of 12 inches possible,
primarily near landfall in northern Florida.

This rainfall may lead to flash and urban flooding, and landslides
across western Cuba.

Areas of flash and urban flooding, some of which may be locally
significant, are expected across portions of the west coast of
Florida, the Florida Panhandle, and southern Georgia Tuesday into
Wednesday, spreading into portions of the eastern Carolinas
Wednesday into Thursday.

SURF: Swells generated by Idalia are affecting portions of the
southern coast of Cuba and eastern Yucatan. These swells are
likely to cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.

TORNADO: A few tornadoes will be possible starting Tuesday along the
west central Florida coast and the tornado threat will spread
northward into the Florida Big Bend area by Tuesday night.

NEXT ADVISORY
-------------
Next intermediate advisory at 100 PM CDT.
Next complete advisory at 400 PM CDT.

$$
Forecaster Brown