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Subtropical Storm Nicole Forecast Discussion


594 
WTNT42 KNHC 080854
TCDAT2

Subtropical Storm Nicole Discussion Number   5
NWS National Hurricane Center Miami FL       AL172022
400 AM EST Tue Nov 08 2022

Nicole appears to be beginning its transition to a tropical storm,
with the low-level center now embedded beneath a relatively small
but persistent burst of deep convection.  The system still has a
broad cloud and wind field, however, with bands of convection
extending over 500 n mi to the east of the center, and gale-force
winds expanding significantly over the northwestern quadrant.  The
initial intensity remains 40 kt based on ship and scatterometer
observations during the past several hours, and an Air Force Reserve
Hurricane Hunter aircraft which measured a peak 925-mb flight-level
wind of 52 kt.  Nicole's center is just north of NOAA buoy 41047, 
and that platform indicates that the minimum pressure has fallen to 
995 mb.

The NOAA buoy and reconnaissance fixes indicate that Nicole's center
has taken a northward jog since the previous advisory, and the
initial motion remains northwestward, or 310/7 kt.  However, a ridge
axis to the north should cause Nicole to turn westward and then
west-southwestward today and tonight, followed by a recurvature
around the western side of an eastward-moving area of high pressure
Wednesday through Friday.  Because of the recent short-term motion
which deviated from the previous forecast track, the track guidance
has shifted northward a bit during the next 2-3 days.  As a result,
the NHC official track forecast has been nudged northward and is
closest to the GFS, ECWMF, and HCCA solutions, and just a bit south
of the TVCA multi-model consensus.

With Nicole's structure beginning to take on more tropical
characteristics, strengthening is likely to commence later today.
Warm 27-28 degree Celsius waters and a more diffluence upper-level
environment are expected to aid this intensification, and the NHC
intensity forecast continues to show Nicole near or at hurricane
strength as it's moving near the northwestern Bahamas and
approaching the east coast of Florida.  This forecast is just above
the highest intensity guidance, with the HWRF, COAMPS-TC, and HCCA
aids showing an intensity of 60-65 kt at 48 hours.  Weakening is
expected after Nicole moves inland over Florida and accelerates
northeastward over the southeastern United States, although the
system could still produce tropical-storm-force winds over the
adjacent offshore waters.  Nicole should be extratropical by day 4
over the Mid-Atlantic U.S., and most of the global models show the
circulation dissipating by day 5, with a separate extratropical low
forming over northern New England or Quebec.


Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected in
portions of the northwestern Bahamas on Wednesday, where a Hurricane
Warning is in effect.

2.  Hurricane conditions are possible across portions of the coast
of southeast and east-central Florida beginning late Wednesday or
Wednesday night, where a Hurricane Watch is in effect.  Tropical
storm conditions are expected in the Tropical Storm Warning areas in
Florida and Georgia beginning early Wednesday.

3. A dangerous storm surge is expected along much of the east coast
of Florida and portions of coastal Georgia where a storm surge
warning is in effect.  The storm surge will be accompanied by
large and damaging waves.  Residents in the warning area should
listen to advice given by local officials.

4. Do not focus on the exact track of Nicole since it is expected to
be a large storm with hazards extending well to the north of the
center, outside of the forecast cone. These hazards are likely to
affect much of the Florida peninsula and portions of the southeast
U.S.

5. Nicole will produce heavy rainfall Wednesday and Thursday across
the Florida Peninsula.  Flash and urban flooding will be possible
across portions of the Florida Peninsula along with renewed river
rises on portions of the St. Johns River. Flash, urban and small
stream flooding will be possible in southeast Georgia and portions
of South Carolina Thursday into Thursday night.


FORECAST POSITIONS AND MAX WINDS

INIT  08/0900Z 27.6N  71.6W   40 KT  45 MPH...SUBTROPICAL STORM
 12H  08/1800Z 27.6N  73.3W   45 KT  50 MPH...TROPICAL STORM
 24H  09/0600Z 27.0N  75.4W   55 KT  65 MPH
 36H  09/1800Z 26.9N  77.4W   60 KT  70 MPH
 48H  10/0600Z 27.6N  79.9W   65 KT  75 MPH
 60H  10/1800Z 29.0N  82.2W   45 KT  50 MPH...INLAND
 72H  11/0600Z 30.9N  83.1W   35 KT  40 MPH...INLAND
 96H  12/0600Z 38.8N  76.1W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  13/0600Z...DISSIPATED

$$
Forecaster Berg




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