Tropical Storm Fabio Forecast Discussion

469 
WTPZ41 KNHC 060846
TCDEP1

Tropical Storm Fabio Discussion Number   4
NWS National Hurricane Center Miami FL       EP062024
200 AM MST Tue Aug 06 2024

Fabio has become better organized this evening.  The satellite 
presentation reveals a developing deep convective band wrapping 
around the southern portion of the cyclone, and a small Central 
Dense Overcast (CDO) with cold cloud tops of -83C that appears to be 
forming over the surface center.  A blend of the Dvorak satellite 
and UW-CIMSS objective intensity estimates, and a recent SATCON 
intensity analysis yields 55 kt for this advisory.

A low shear and moist thermodynamic environment should allow Fabio 
to strengthen before the cyclone directly interacts and becomes 
absorbed by Emilia.  The deterministic guidance also shows an 
upper-level low moving toward Fabio from the northeast and producing 
favorable upper diffluent flow over the northeast portion of the 
cyclone.  The new NHC intensity forecast is a bit above the previous 
one and now shows Fabio's peak intensity at 60 kt, which is close to 
the IVCN and HCCA consensus aids.  It's worth noting, however, that 
the initialization of the two tropical cyclones in the GFS seems to 
be the most reasonable based on the structure and intensity of both 
cyclones.  Therefore, a change in the forecast philosophy may be 
deemed necessary in subsequent advisories.

Fabio's initial motion is estimated to be west-northwestward or 
295/15 kt.  The global models show that Fabio will move between 
Emilia to the west-southwest and a mid-tropospheric ridge extending 
from the west Gulf of Mexico to the southern Baja California 
Peninsula during the next couple of days.  The models also generally 
agree that Emilia will capture and absorb Fabio, but the exact 
timing for which this will occur is in some doubt. The 
ECMWF/CMC/UKMET and the COAMPS-TC show this evolution taking place 
within 36 hours, while the GFS run indicates the two tropical 
cyclones cyclonically orbiting around each other during the next 
three to four days.  The best solution at this time is to show a 
similar scenario to the previous advisory and hedge toward the 
better-performing consensus guidance with Fabio becoming absorbed by 
Emilia by mid-week.


FORECAST POSITIONS AND MAX WINDS

INIT  06/0900Z 16.9N 110.8W   55 KT  65 MPH
 12H  06/1800Z 17.9N 113.1W   55 KT  65 MPH
 24H  07/0600Z 18.6N 116.2W   60 KT  70 MPH
 36H  07/1800Z 18.6N 119.5W   60 KT  70 MPH
 48H  08/0600Z...DISSIPATED

$$
Forecaster Roberts