Atlantic Basin Tropical Cyclones

Hurricane Ian Forecast Discussion


959 
WTNT44 KNHC 301455
TCDAT4

Hurricane Ian Discussion Number  32
NWS National Hurricane Center Miami FL       AL092022
1100 AM EDT Fri Sep 30 2022

Satellite images show that Ian has re-developed deep convection
near the center, with frontal features away from the core of the
cyclone.  Additionally, a primitive eyewall has formed around about
half of the circulation.  An Air Force Reserve Hurricane Hunter
aircraft recently found peak flight-level winds of 80 kt and SFMR
winds of 72 kt.  Radar data is also showing winds of up to 85 kt 
around 10 thousand feet, with hurricane-force winds now in the
northeastern quadrant.  These values support the initial wind speed
of 75 kt.  NOAA buoy 41004 near the center recently reported a
minimum pressure of 981 mb with some wind, which supports the
advisory value.

Ian is now moving faster to the north, around 12 kt, and should
continue to accelerate to the north-northwest later today due to
a shortwave trough over the southeastern United States.  The new
forecast is adjusted a bit to the east, but should still lead to a
landfall in South Carolina this afternoon.  Little change in
intensity is expected before Ian makes landfall, due to competing
influences of strong shear versus baroclinic forcing from the trough
over water waters.   Ian should rapidly transition into an
extratropical low tonight after landfall, and dissipate by Saturday
night.

It should be emphasized that dangerous winds and life-threatening
storm surge should rapidly increase during the next few hours in
the Storm Surge and Hurricane Warning areas due to Ian moving faster
toward the coast.


Key Messages:

1. There is a danger of life-threatening storm surge today along the
coasts of the Carolinas within the Storm Surge Warning areas.

2. Hurricane-force winds are expected along the coasts of South
Carolina and southeastern North Carolina within the Hurricane
Warning area soon.  Hurricane conditions are possible in North
Carolina within the Hurricane Watch area by this afternoon.
Preparations should be rushed to completion.

3. Ongoing major-to-record river flooding will continue through
next week across portions of central Florida. Considerable flooding
is expected today across portions of coastal and northeast South
Carolina, coastal North Carolina and southeast Virginia. Locally
considerable flooding is possible across portions of northwest North
Carolina and southern Virginia today into early Saturday.


FORECAST POSITIONS AND MAX WINDS

INIT  30/1500Z 32.4N  79.0W   75 KT  85 MPH
 12H  01/0000Z 34.1N  79.4W   50 KT  60 MPH...POST-TROP/EXTRATROP
 24H  01/1200Z 36.0N  80.0W   25 KT  30 MPH...POST-TROP/EXTRATROP
 36H  02/0000Z 37.5N  80.0W   15 KT  15 MPH...POST-TROP/EXTRATROP
 48H  02/1200Z...DISSIPATED

$$
Forecaster Blake




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