Major Hurricane Ian
Posted: Sat Sep 24, 2022 11:00 am
Folks... I am breaking out Ian on its own thread since it has a high chance at impacting the CONUS. Please discuss all things Ian here. Currently as of 11am advisory, Ian has winds of 45 mph moving W at 15. Per the satellite image below, you can see good outflow on the southern side and western but shear cutting off the cloud tops on its northern and eastern sides. The convection still isn't going to be able to wrap around the center until it moves further west into the Caribbean where there is less shear and more room for development.
Model guidance is below...
Ian should begin to strengthen over the next 24 hours as low shear is ahead of it from the storm itself to Florida.
Finally... 11am statement from NHC:
Tropical Storm Ian Advisory Number 6
NWS National Hurricane Center Miami FL AL092022
1100 AM EDT Sat Sep 24 2022
...IAN FORECAST TO RAPIDLY STRENGTHEN LATER THIS WEEKEND...
...HURRICANE CONDITIONS POSSIBLE IN THE CAYMAN ISLANDS EARLY
MONDAY...
SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.4N 75.2W
ABOUT 270 MI...435 KM SSE OF KINGSTON JAMAICA
ABOUT 520 MI...840 KM SE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES
Tropical Storm Ian Discussion Number 6
NWS National Hurricane Center Miami FL AL092022
1100 AM EDT Sat Sep 24 2022
Ian still has an asymmetric appearance in satellite imagery this
morning, with most of the deep convection located over the western
portion of the circulation. Tail Doppler radar and dropsonde data
from a NOAA Hurricane Hunter aircraft indicate the cyclone is still
vertically tilted, with the low- to mid-level center displaced to
the south of the surface center. This structure is likely a product
of the northerly shear that has affected the cyclone since genesis.
The aircraft reported 700-mb flight-level winds of 43 kt and SFMR
retrievals slightly above 35 kt, which supports keeping the initial
intensity at 40 kt for this advisory.
The initial motion is a bit south of due west at 260/13 kt. A
generally westward motion is expected through tonight as the cyclone
is steered by a narrow ridge to its north. Ian is forecast to turn
northwestward on Sunday and north-northwestward on Monday as it
moves across the northwestern Caribbean Sea around the periphery of
the ridge. The NHC track forecast during this period has been
adjusted slightly south and west of the previous one, in line with
the track consensus aids. Beyond 72 h, there is still a large amount
of cross-track spread in the guidance as Ian emerges into the
eastern Gulf of Mexico and approaches Florida. Hopefully, data
collected from special radiosonde releases beginning later today and
a scheduled NOAA G-IV flight will help resolve the steering flow
around Ian and deep-layer trough that is forecast to be over the
eastern U.S. early next week. The guidance envelope has once again
shifted westward this cycle, and the official NHC track forecast has
been adjusted in this direction as well, though it still lies
slightly to the east of the TVCA and HCCA aids. Further adjustments
to the track forecast may be needed given the increased uncertainty
in the day 3-5 period.
Ian is moving into a lower shear environment over very warm waters,
and it should not take long for the system to shed its tilted
structure and develop an inner core. Once that occurs, significant
to rapid intensification is expected while Ian crosses the
northwestern Caribbean Sea. The intensity guidance unanimously
supports strengthening during the next several days, and the
SHIPS-RII probabilities indicate a 67 percent chance of a 65-kt
intensity increase in 72 h. Therefore, the NHC track forecast has
been raised from the previous one, showing Ian becoming a hurricane
by late Sunday and approaching western Cuba at or near major
hurricane strength by Monday night. Limited land interaction is
expected as the cyclone quickly passes over western Cuba, and Ian
is forecast to be a major hurricane over the eastern Gulf of Mexico
on Tuesday and Wednesday as it approaches the west coast of Florida.
Model guidance is below...
Ian should begin to strengthen over the next 24 hours as low shear is ahead of it from the storm itself to Florida.
Finally... 11am statement from NHC:
Tropical Storm Ian Advisory Number 6
NWS National Hurricane Center Miami FL AL092022
1100 AM EDT Sat Sep 24 2022
...IAN FORECAST TO RAPIDLY STRENGTHEN LATER THIS WEEKEND...
...HURRICANE CONDITIONS POSSIBLE IN THE CAYMAN ISLANDS EARLY
MONDAY...
SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.4N 75.2W
ABOUT 270 MI...435 KM SSE OF KINGSTON JAMAICA
ABOUT 520 MI...840 KM SE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES
Tropical Storm Ian Discussion Number 6
NWS National Hurricane Center Miami FL AL092022
1100 AM EDT Sat Sep 24 2022
Ian still has an asymmetric appearance in satellite imagery this
morning, with most of the deep convection located over the western
portion of the circulation. Tail Doppler radar and dropsonde data
from a NOAA Hurricane Hunter aircraft indicate the cyclone is still
vertically tilted, with the low- to mid-level center displaced to
the south of the surface center. This structure is likely a product
of the northerly shear that has affected the cyclone since genesis.
The aircraft reported 700-mb flight-level winds of 43 kt and SFMR
retrievals slightly above 35 kt, which supports keeping the initial
intensity at 40 kt for this advisory.
The initial motion is a bit south of due west at 260/13 kt. A
generally westward motion is expected through tonight as the cyclone
is steered by a narrow ridge to its north. Ian is forecast to turn
northwestward on Sunday and north-northwestward on Monday as it
moves across the northwestern Caribbean Sea around the periphery of
the ridge. The NHC track forecast during this period has been
adjusted slightly south and west of the previous one, in line with
the track consensus aids. Beyond 72 h, there is still a large amount
of cross-track spread in the guidance as Ian emerges into the
eastern Gulf of Mexico and approaches Florida. Hopefully, data
collected from special radiosonde releases beginning later today and
a scheduled NOAA G-IV flight will help resolve the steering flow
around Ian and deep-layer trough that is forecast to be over the
eastern U.S. early next week. The guidance envelope has once again
shifted westward this cycle, and the official NHC track forecast has
been adjusted in this direction as well, though it still lies
slightly to the east of the TVCA and HCCA aids. Further adjustments
to the track forecast may be needed given the increased uncertainty
in the day 3-5 period.
Ian is moving into a lower shear environment over very warm waters,
and it should not take long for the system to shed its tilted
structure and develop an inner core. Once that occurs, significant
to rapid intensification is expected while Ian crosses the
northwestern Caribbean Sea. The intensity guidance unanimously
supports strengthening during the next several days, and the
SHIPS-RII probabilities indicate a 67 percent chance of a 65-kt
intensity increase in 72 h. Therefore, the NHC track forecast has
been raised from the previous one, showing Ian becoming a hurricane
by late Sunday and approaching western Cuba at or near major
hurricane strength by Monday night. Limited land interaction is
expected as the cyclone quickly passes over western Cuba, and Ian
is forecast to be a major hurricane over the eastern Gulf of Mexico
on Tuesday and Wednesday as it approaches the west coast of Florida.