Tropical Storm Florence Discussion Number  10
NWS National Hurricane Center Miami FL       AL062018
500 PM AST Sat Sep 01 2018

The cloud pattern has continued to improve with a circular area of
convection near the center, and a cyclonically curved band
surrounding the system.  The upper-level outflow is fair in all
quadrants. Although the cloud pattern is better organized, the
Dvorak T-numbers have not changed, and only support 40 kt at this
time.

Florence has a couple of more days embedded within a low-shear
environment which supports strengthening, but it is also currently
heading toward marginal SSTs. By the time the cyclone reaches
warmer waters again, the shear is forecast to be unfavorable. The
best option at this time is to show only a very modest strengthening
at the rate indicated by the intensity consensus aids.

Florence has been moving toward the west-northwest or 285 degrees
at 12 to 14 kt. No change in track is anticipated during the next 3
days while Florence is located to the south of the Atlantic
subtropical ridge.  After that time, Florence will reach a break in
the ridge causing the cyclone to turn toward the northwest with a
decrease in forward speed.  The latter portion of the forecast is
uncertain since the strength of the subtropical ridge to the north
has been fluctuating from run to run in each model. At this time,
the overall guidance has been shifting a little bit westward,
suggesting a stronger ridge. On this basis, the NHC forecast was
adjusted slightly in that direction at the end of the forecast
period.


FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 15.6N  29.0W   40 KT  45 MPH
12H  02/0600Z 16.2N  31.0W   45 KT  50 MPH
24H  02/1800Z 16.8N  33.7W   50 KT  60 MPH
36H  03/0600Z 17.5N  36.5W   55 KT  65 MPH
48H  03/1800Z 18.0N  39.0W   55 KT  65 MPH
72H  04/1800Z 19.5N  43.5W   55 KT  65 MPH
96H  05/1800Z 21.5N  48.0W   50 KT  60 MPH
120H  06/1800Z 23.5N  52.0W   50 KT  60 MPH

$$
Forecaster Avila