Pacific Hurricane Feed

Tropical Depression Eighteen-E Forecast Discussion

WTPZ43 KNHC 070237

Tropical Depression Eighteen-E Discussion Number  11
NWS National Hurricane Center Miami FL       EP182021
1000 PM CDT Sat Nov 06 2021

The structure of the depression has not changed much during the past 
several hours.  Deep convection continues to pulse near the center 
and in bands on the system's south side.  Last-light visible 
satellite images indicate that the circulation is quite stretched, 
likely due to the Gulf of Tehuantepec gap wind event.  In fact, 
confidence in the center location is low and somewhat based on 
continuity. Hopefully the next round of ASCAT data and microwave 
images will provide a better look at how organized the circulation 
is overnight.  For now, the system is held as a 30-kt depression 
following the Dvorak estimates and the earlier ASCAT data.

The depression continues to move just south of due west at 265/11 
kt, and the system is at a very low latitude near 8N.  This motion 
is expected to continue overnight, but a general westward to 
west-northwestward motion is likely to occur after that as the 
system moves within the flow on the south side of a low- to 
mid-level ridge.  Except for the UKMET, which is a northern outlier, 
most of the models show a similar solution with some speed 
differences.  The NHC track forecast is near the middle of the 
guidance envelope and just an update of the previous one.

The system has been steady state since it formed a little more than 
two days ago despite being in generally favorable large-scale 
conditions.  Some of the models suggest that the depression will 
slowly gain strength during the next several days, which is possible 
since the environmental conditions are forecast to be at least 
marginally conducive.  However, since the depression has not 
strengthened yet and because the circulation might not be well 
organized, the NHC intensity forecast remains on the low side of the 
guidance envelope through the period.


INIT  07/0300Z  8.3N  98.6W   30 KT  35 MPH
 12H  07/1200Z  8.4N 100.3W   30 KT  35 MPH
 24H  08/0000Z  8.8N 102.7W   30 KT  35 MPH
 36H  08/1200Z  9.2N 105.2W   35 KT  40 MPH
 48H  09/0000Z  9.6N 107.7W   35 KT  40 MPH
 60H  09/1200Z 10.0N 110.1W   35 KT  40 MPH
 72H  10/0000Z 10.3N 112.6W   35 KT  40 MPH
 96H  11/0000Z 10.6N 117.6W   35 KT  40 MPH
120H  12/0000Z 10.6N 123.0W   35 KT  40 MPH

Forecaster Cangialosi

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