Tropical Storm HERMINE Advisory Fr, 23.09.

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM

Tropical Depression Ten Discussion Number   1
NWS National Hurricane Center Miami FL       AL102022
200 PM CVT Fri Sep 23 2022

Satellite images indicate that the strong tropical wave that NHC has
been tracking for several days over western Africa has developed a
well-defined surface center over the far eastern Atlantic with
organized bands of convection.  Dropsonde data from a DC-8 aircraft
with the NASA field program Convective Processes EXperiment-Cabo
Verde (CPEX-CV) has been quite useful in determining the central
pressure and surface circulation definition of the low, with the
central pressure of 1003 mb based on the dropsondes.  The initial
wind speed is set to 30 kt, perhaps conservatively since the eastern
side of the circulation has not been sampled by scatterometer or
aircraft data.

The system is moving north-northwestward at about 10 kt.  A large
break in the eastern Atlantic subtropical ridge should cause this
system to move generally northward ahead of a mid-level trough
before turning westward and accelerating as a shallow system beneath
the low-level ridge.  The forecast is close to the model consensus,
with heavier weight being placed on the global models than the
regional hurricane track models.

The depression has about a day over warm water in light to moderate
shear before all the models blast the system with strong upper-
level southwesterly winds.  Most of the guidance shows this system
becoming a tropical storm before weakening significantly by late
this weekend and dissipating early next week.  The official wind
speed prediction is near the NOAA corrected-consensus guidance HCCA.

Note that 2 to 4 inches of rain is possible over the Canary Islands
through this weekend due to a combination of the mid-level trough
and moisture from this system, which is a bit unusual for that area.


FORECAST POSITIONS AND MAX WINDS

INIT  23/1500Z 17.9N  19.8W   30 KT  35 MPH
 12H  24/0000Z 19.2N  20.5W   35 KT  40 MPH
 24H  24/1200Z 21.0N  21.0W   35 KT  40 MPH
 36H  25/0000Z 22.3N  21.1W   30 KT  35 MPH
 48H  25/1200Z 23.2N  21.0W   25 KT  30 MPH
 60H  26/0000Z 23.9N  21.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  26/1200Z 24.3N  21.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  27/1200Z 26.0N  26.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  28/1200Z...DISSIPATED

$$
Forecaster Blake