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Tropical Depression Eighteen-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP182023
1000 AM CDT Sun Oct 22 2023

The area of low pressure (91E) that NHC has been monitoring has now 
become a tropical depression well offshore of southern Mexico.  
Satellite images show that deep convection has been increasing and 
consolidating near the center, and ASCAT data from several hours ago 
indicated that the system had developed a well-defined center.  
Dvorak estimates from TAFB and SAB have increased to 2.5/35 kt, but 
the initial intensity is set a little lower at 30 kt since the ASCAT 
pass suggested that the Dvorak estimates have been running a little 
high. 

The depression is drifting northward at 2 kt.  A continued slow 
northward motion is expected during the next couple of days as the 
system moves in the light steering flow between a ridge to its 
northeast and a trough to its northwest.  Beyond a few days, the 
weakening system will likely turn westward in the low-level flow.  
However, by the end of the forecast period, there is quite a bit of 
spread in the track guidance making the long-term forecast somewhat 
uncertain.   The NHC track forecast is near the various consensus 
aids.

Some slight strengthening is possible during the next couple of days 
while the depression remains in generally conducive environmental 
conditions.  However, beyond that time, an increase in vertical wind 
shear should cause slow weakening, and most of the models show the 
system decoupling or dissipating by the end of the forecast period.  
The NHC intensity forecast lies near the middle of the guidance 
envelope.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/1500Z  9.9N  96.7W   30 KT  35 MPH
 12H  23/0000Z 10.2N  96.8W   35 KT  40 MPH
 24H  23/1200Z 10.8N  96.8W   35 KT  40 MPH
 36H  24/0000Z 11.8N  96.7W   40 KT  45 MPH
 48H  24/1200Z 12.8N  96.9W   40 KT  45 MPH
 60H  25/0000Z 13.4N  97.4W   40 KT  45 MPH
 72H  25/1200Z 13.7N  97.7W   40 KT  45 MPH
 96H  26/1200Z 13.9N  98.1W   35 KT  40 MPH
120H  27/1200Z 13.9N  98.6W   30 KT  35 MPH
 
$$
Forecaster Cangialosi/Bucci
 
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