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Tropical Storm Florence Discussion Number 67
NWS National Hurricane Center Miami FL AL062018
1100 PM EDT Sat Sep 15 2018
Florence's center continues to trudge slowly westward across South
Carolina, but heavy rainbands are still streaming inland from the
ocean across extreme southeastern North Carolina. The NOS station
at the Johnny Mercer Pier in Wrightsville Beach in the vicinity of
these rainbands is the lone observing station that has still been
reporting sustained tropical-storm-force winds, and based on the
most recent observations, Florence's maximum winds are estimated to
be 35 kt.
Florence is expected to weaken to a tropical depression within the
next 6-12 hours, with the global model fields showing winds
decreasing below 35 kt near the coast very soon. Continued
weakening is anticipated while Florence moves farther inland, and
it is likely to become a remnant low in about 36 hours when its
circulation becomes less defined. Florence is then expected to
become a strengthening extratropical low between days 3 and 5 when
it exits the Northeast U.S. coast and moves out to sea.
The initial motion is still very slow toward the west, or 275/3 kt.
A mid-level ridge across the Upper Midwest and Great Lakes is
currently blocking Florence from making much headway, but that
feature is expected to slide eastward to the western Atlantic
during the next 24 hours. This should allow Florence to recurve
and accelerate across the Ohio Valley and the northeastern U.S.
during the next 3 days, and then accelerate further toward the
east-northeast over the Atlantic Ocean on days 4 and 5. The new
NHC track forecast is essentially an update of the previous one and
is close to the various model consensus aids.
1. Life-threatening, catastrophic flash floods and prolonged
significant river flooding are likely over portions of the Carolinas
and the southern to central Appalachians from western North Carolina
into west-central Virginia and far eastern West Virginia through
early next week, as Florence moves slowly inland. In addition to
the flash flood and flooding threat, landslides are also possible in
the higher terrain of the southern and central Appalachians across
western North Carolina into southwest Virginia.
2. Tropical storm conditions will continue along the coast within
the tropical storm warning area and also well inland across portions
of South Carolina and North Carolina overnight.
3. Large swells affecting Bermuda, portions of the U.S. East Coast,
and the northwestern and central Bahamas will continue this week,
resulting in life-threatening surf and rip currents.
FORECAST POSITIONS AND MAX WINDS
INIT 16/0300Z 33.7N 80.5W 35 KT 40 MPH...INLAND
12H 16/1200Z 34.3N 81.6W 30 KT 35 MPH...INLAND
24H 17/0000Z 35.8N 83.2W 25 KT 30 MPH...INLAND
36H 17/1200Z 37.8N 83.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 18/0000Z 39.2N 81.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 19/0000Z 41.5N 71.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
96H 20/0000Z 43.0N 59.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 21/0000Z 45.5N 47.0W 40 KT 45 MPH...POST-TROP/EXTRATROP