Tropical Storm Franklin Discussion Number   8
NWS National Hurricane Center Miami FL       AL082023
1100 AM EDT Tue Aug 22 2023

It is unclear this morning if Franklin still has a well-defined
center of circulation.  Visible satellite images suggest that broad
low-level turning is occurring well to the west of the bulk of
Franklin's deep convection, and there is no clear evidence that a
center exists near, or that a new center if re-forming beneath, the
convection.  It appears that scatterometer will miss Franklin and
be of no help in assessing the wind field, but a NOAA Hurricane
Hunter aircraft is scheduled to investigate the system later this
afternoon.  For now, the initial intensity is held at 45 kt, which
is right in the middle of the various subjective and objective
satellite estimates.

If Franklin does still have a center, it is assumed to have jumped
or re-formed a bit to the west where there is new convection.  This
position gives the storm an overall motion over the past 12 hours
toward the northwest (325 degrees) at 6 kt.  Franklin is positioned
within the southern extent of a large mid-level trough, which
includes a mid-/upper-level low centered south of Bermuda.  While
the steering flow is weak, this should cause Franklin to move slowly
northward and then northeastward for the next 4 days or so.  By day
5, a new shortwave trough is likely to develop over New England,
with ridging strengthening over the central Atlantic, and Franklin
is forecast to turn back toward the north at that time.  Largely
because of the adjustment in the initial position, all of the track
guidance has shifted westward on this cycle.  The NHC track
forecast has also been moved westward, although it is on the
eastern side of the guidance envelope and fairly close to the
typically-reliable HCCA consensus aid.  That said, there is
greater-than-usual uncertainty in Franklin's forecast track given
potential re-formations of the center.

Moderate-to-strong westerly shear is expected to continue over
Franklin for the next 4 days or so.  In addition, the system is
forecast to move over the rugged terrain of Hispaniola within the
next 24-36 hours.  As a result, little change in strength is
anticipated before Franklin reaches Hispaniola, and some weakening
is likely while it is crossing the island.  Some intensification
is then noted in the 3-5 day period when environmental conditions
begin to become a little more conducive for strengthening.  The NHC
intensity forecast is near the HCCA and IVCN consensus aids for
much of the 5-day forecast period.


KEY MESSAGES:

1. Heavy rainfall from Franklin is expected across portions of
Puerto Rico and Hispaniola into Thursday. The heavy rainfall may
produce areas of flash and urban flooding as well as river rises and
mudslides. Across Hispaniola, significant and potentially
life-threatening flash flooding is possible Tuesday into Wednesday.

2. Franklin is expected to bring tropical storm conditions to
portions of the Dominican Republic and Haiti, where Tropical Storm
Warnings are in effect, beginning later today and continuing through
Wednesday.


FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 15.5N  71.1W   45 KT  50 MPH
12H  23/0000Z 16.5N  71.3W   50 KT  60 MPH
24H  23/1200Z 18.3N  70.9W   45 KT  50 MPH...S COAST OF DOM REPUB
36H  24/0000Z 20.4N  70.2W   40 KT  45 MPH...OVER WATER
48H  24/1200Z 22.1N  69.3W   40 KT  45 MPH
60H  25/0000Z 22.9N  68.2W   45 KT  50 MPH
72H  25/1200Z 23.3N  67.1W   50 KT  60 MPH
96H  26/1200Z 24.2N  66.3W   60 KT  70 MPH
120H  27/1200Z 27.1N  67.1W   70 KT  80 MPH

$$
Forecaster Berg