Atlantic Basin Tropical Cyclones

Tropical Storm Nicole Forecast Discussion


360 
WTNT42 KNHC 090859
TCDAT2

Tropical Storm Nicole Discussion Number   9
NWS National Hurricane Center Miami FL       AL172022
400 AM EST Wed Nov 09 2022

Nicole's satellite presentation has not changed since last evening.
The associated convection is fairly fragmented, and cloud-top
temperatures are not particularly cold compared to a typical
tropical cyclone (they're only as cold as -50 degrees Celsius near
the center).  The initial intensity remains 60 kt based on data
from last evening's reconnaissance mission.

Aircraft fixes and radar data from the Bahamas indicate that Nicole
has continued to move west-southwestward (250/11 kt), even a little
south of the previous NHC track prediction.  However, track model
guidance indicates that Nicole should turn westward soon, and its
center is forecast to move across the Abacos and Grand Bahama
Island later today and approach the southeast or east-central coast
of Florida tonight.  After 24 hours, high pressure over the
southeastern U.S. is expected to slide eastward over the Atlantic,
and that will cause Nicole to recurve around its western flank,
moving across northern Florida or the northeastern Gulf of Mexico,
and then across the southeastern U.S.  Nicole is then expected to
accelerate northeastward toward the Mid-Atlantic states in 60-72
hours ahead of an approaching deep-layer trough and cold front.
Due to Nicole's recent short-term motion, the NHC official forecast
has been nudged southward and westward during the first 48 hours
and lies fairly close to the ECMWF and TVCA multi-model consensus.
It's worth noting that a few models, including the GFS, HWRF, and
HCCA, are a little west of the official forecast over the
northeastern Gulf of Mexico and Florida Panhandle.

Nicole will continue to move over warm SSTs of 27-28 degrees Celsius
today, although the cyclone will likely also be contending with some
shear and a dry and not particularly unstable environment.
Therefore, only slight additional strengthening is anticipated, and
Nicole could still become a hurricane later today while it moves
across the northwestern Bahamas and reaches the east coast of
Florida.  Weakening is expected once the center moves over Florida,
and Nicole is forecast to weaken below tropical storm strength by 60
hours once it's over Georgia or South Carolina.  Nicole is expected
to merge with a cold front and become extratropical over the
Mid-Atlantic by day 3, although most global models indicate that
feature will dissipate soon thereafter, with a secondary
extratropical low developing farther north over New England or
eastern Canada.

Scatterometer data from last evening indicated that Nicole's
tropical-storm-force wind field continues to expand on its northern
side, and that has been reflected in the new forecast.


Key Messages:

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

2. Hurricane conditions are expected across portions of the coast
of southeast and east-central Florida beginning this evening or
tonight, where a Hurricane Warning is in effect.  Tropical
storm conditions have begun along the east coast of Florida in the
warning areas and will spread northward to Georgia and South
Carolina later today.  Tropical storm conditions are expected to
begin along the west coast of Florida within the warning area this
evening or tonight.

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
United States.

5. Nicole will produce heavy rainfall today into Thursday across the
Florida Peninsula.  Flash and urban flooding will be likely across
portions of the Florida Peninsula along with possible renewed river
rises on the St. Johns River.  Isolated flash, urban, and small
stream flooding will also be possible on Friday in the Southeast
through the southern and central Appalachians, including the Blue
Ridge Mountains, and extending northward through west-central
Pennsylvania into western New York by Friday night.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 26.6N  75.7W   60 KT  70 MPH
 12H  09/1800Z 26.6N  77.7W   65 KT  75 MPH
 24H  10/0600Z 27.1N  80.4W   60 KT  70 MPH...INLAND
 36H  10/1800Z 28.5N  82.9W   45 KT  50 MPH...OVER WATER
 48H  11/0600Z 30.7N  84.1W   35 KT  40 MPH...INLAND
 60H  11/1800Z 34.1N  82.5W   30 KT  35 MPH...INLAND
 72H  12/0600Z 38.7N  78.2W   35 KT  40 MPH...POST-TROP/EXTRATROP
 96H  13/0600Z...DISSIPATED

$$
Forecaster Berg




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