Post by MobileWeatherWatcher on Aug 29, 2023 21:00:26 GMT -6
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
Hurricane Idalia Discussion Number 14
NWS National Hurricane Center Miami FL AL102023
1100 PM EDT Tue Aug 29 2023
Satellite and NWS radar imagery show that Idalia is becoming
increasingly more organized. The eye on the Tampa WSR-88D is
becoming better defined and the cloud pattern on GOES 16 imagery
consists of a growing Central Dense Overcast with a strong
convective band over the eastern semicircle of the circulation.
Reconnaissance aircraft measurements show that the central pressure
is steadily falling and is now around 958 mb. Flight-level and
SFMR-observed winds along with Doppler velocity data from the
aircraft support an intensity of 95 kt for this advisory.
Idalia is now moving faster toward the north or slightly east of
north with a motion estimate of 010/16 kt. The hurricane is moving
between a mid-level trough over the northwestern Gulf of Mexico and
ridge over the Bahamas and Greater Antilles. The system is expected
to turn north-northeastward within the next 12 hours, make landfall
along the northeastern Gulf coast, and then move northeastward to
eastward on the southern side of a mid-level trough moving off the
northeast U.S. coast. The 12-hour track forecast point for this
advisory has been nudged a bit westward, a little west of the model
consensus, but close to the latest GFS and ECMWF solutions. It
should be noted that some credible models, i.e. the HAFS-A and
HAFS-B predictions, are even a little father west.
After landfall, Idalia is expected to move near or along the coast
of Georgia and the Carolinas in 24-36 hours. Uncertainty in the
track forecast beyond 48 hours remains quite large, with some of
the global models turning Idalia southward, while some of the
regional hurricane models show the storm moving out to sea. Given
the uncertainties, the official track forecast shows a slow
southeastward motion in 4 to 5 days.
Based on the current strengthening trend and the favorable
thermodynamic and oceanic conditions, significant strengthening
seems likely up to landfall. The new official intensity forecast
calls for Idalia to reach category 4 strength at landfall. This is
fairly close to the HAFS And HWRF regional hurricane model
simulations. After the center moves back over the Atlantic,
significant restrengthening is not anticipated at this time due to
the expectation of strong vertical west-southwesterly vertical wind
shear.
Dangerous winds are likely to spread well inland near the path of
Idalia due to its relatively fast forward motion.
KEY MESSAGES:
1. Catastrophic impacts from storm surge inundation of 12 to 16 feet
above ground level and destructive waves are expected somewhere
between the Wakulla/Jefferson County line and Yankeetown, Florida.
Life-threatening storm surge inundation is likely elsewhere along
portions of the Florida Gulf Coast where a Storm Surge Warning is in
effect. Residents in these areas should follow any advice given by
local officials.
2. There is the potential for destructive life-threatening winds
where the core of Idalia moves onshore in the Big Bend region of
Florida, with hurricane conditions expected elsewhere in portions of
the Hurricane Warning area along the Florida Gulf Coast. Strong
winds will also spread inland across portions of northern Florida
and southern Georgia near the track of the center of Idalia where
Hurricane Warnings are in effect. Residents in these areas should be
prepared for long-duration power outages. Damaging hurricane-force
winds are possible in portions of eastern Georgia and southeastern
South Carolina where Hurricane Watches are in effect.
3. Areas of flash, urban, and moderate river flooding, with locally
considerable impacts, are expected across the Florida Big Bend,
central Georgia and South Carolina, through eastern North Carolina
into Thursday.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0300Z 27.7N 84.5W 95 KT 110 MPH
12H 30/1200Z 30.0N 83.9W 115 KT 130 MPH...ON COAST
24H 31/0000Z 32.3N 81.3W 70 KT 80 MPH...INLAND
36H 31/1200Z 33.5N 78.6W 50 KT 60 MPH...OVER WATER
48H 01/0000Z 33.8N 75.0W 50 KT 60 MPH
60H 01/1200Z 33.5N 72.5W 50 KT 60 MPH
72H 02/0000Z 32.9N 71.0W 45 KT 50 MPH
96H 03/0000Z 32.0N 69.4W 45 KT 50 MPH
120H 04/0000Z 31.0N 68.4W 45 KT 50 MPH
$$
Forecaster Pasch
TTAA00 KNHC DDHHMM
Hurricane Idalia Discussion Number 14
NWS National Hurricane Center Miami FL AL102023
1100 PM EDT Tue Aug 29 2023
Satellite and NWS radar imagery show that Idalia is becoming
increasingly more organized. The eye on the Tampa WSR-88D is
becoming better defined and the cloud pattern on GOES 16 imagery
consists of a growing Central Dense Overcast with a strong
convective band over the eastern semicircle of the circulation.
Reconnaissance aircraft measurements show that the central pressure
is steadily falling and is now around 958 mb. Flight-level and
SFMR-observed winds along with Doppler velocity data from the
aircraft support an intensity of 95 kt for this advisory.
Idalia is now moving faster toward the north or slightly east of
north with a motion estimate of 010/16 kt. The hurricane is moving
between a mid-level trough over the northwestern Gulf of Mexico and
ridge over the Bahamas and Greater Antilles. The system is expected
to turn north-northeastward within the next 12 hours, make landfall
along the northeastern Gulf coast, and then move northeastward to
eastward on the southern side of a mid-level trough moving off the
northeast U.S. coast. The 12-hour track forecast point for this
advisory has been nudged a bit westward, a little west of the model
consensus, but close to the latest GFS and ECMWF solutions. It
should be noted that some credible models, i.e. the HAFS-A and
HAFS-B predictions, are even a little father west.
After landfall, Idalia is expected to move near or along the coast
of Georgia and the Carolinas in 24-36 hours. Uncertainty in the
track forecast beyond 48 hours remains quite large, with some of
the global models turning Idalia southward, while some of the
regional hurricane models show the storm moving out to sea. Given
the uncertainties, the official track forecast shows a slow
southeastward motion in 4 to 5 days.
Based on the current strengthening trend and the favorable
thermodynamic and oceanic conditions, significant strengthening
seems likely up to landfall. The new official intensity forecast
calls for Idalia to reach category 4 strength at landfall. This is
fairly close to the HAFS And HWRF regional hurricane model
simulations. After the center moves back over the Atlantic,
significant restrengthening is not anticipated at this time due to
the expectation of strong vertical west-southwesterly vertical wind
shear.
Dangerous winds are likely to spread well inland near the path of
Idalia due to its relatively fast forward motion.
KEY MESSAGES:
1. Catastrophic impacts from storm surge inundation of 12 to 16 feet
above ground level and destructive waves are expected somewhere
between the Wakulla/Jefferson County line and Yankeetown, Florida.
Life-threatening storm surge inundation is likely elsewhere along
portions of the Florida Gulf Coast where a Storm Surge Warning is in
effect. Residents in these areas should follow any advice given by
local officials.
2. There is the potential for destructive life-threatening winds
where the core of Idalia moves onshore in the Big Bend region of
Florida, with hurricane conditions expected elsewhere in portions of
the Hurricane Warning area along the Florida Gulf Coast. Strong
winds will also spread inland across portions of northern Florida
and southern Georgia near the track of the center of Idalia where
Hurricane Warnings are in effect. Residents in these areas should be
prepared for long-duration power outages. Damaging hurricane-force
winds are possible in portions of eastern Georgia and southeastern
South Carolina where Hurricane Watches are in effect.
3. Areas of flash, urban, and moderate river flooding, with locally
considerable impacts, are expected across the Florida Big Bend,
central Georgia and South Carolina, through eastern North Carolina
into Thursday.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0300Z 27.7N 84.5W 95 KT 110 MPH
12H 30/1200Z 30.0N 83.9W 115 KT 130 MPH...ON COAST
24H 31/0000Z 32.3N 81.3W 70 KT 80 MPH...INLAND
36H 31/1200Z 33.5N 78.6W 50 KT 60 MPH...OVER WATER
48H 01/0000Z 33.8N 75.0W 50 KT 60 MPH
60H 01/1200Z 33.5N 72.5W 50 KT 60 MPH
72H 02/0000Z 32.9N 71.0W 45 KT 50 MPH
96H 03/0000Z 32.0N 69.4W 45 KT 50 MPH
120H 04/0000Z 31.0N 68.4W 45 KT 50 MPH
$$
Forecaster Pasch
