000
WTPZ42 KNHC 202058
TCDEP2
 
Tropical Depression Seventeen-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP172026
300 PM CST Sun Sep 20 2026

The tropical disturbance to the south of Mexico, formerly Invest 
99E, has become better organized with some convective banding 
features over its eastern semicircle.  Although a recent 
scatterometer pass missed the circulation, low cloud motions 
indicate that the system now has enough of a low-level circulation 
to qualify as a tropical depression with an initial intensity of 30 
kt this advisory. 

The center has been difficult to track so far so the initial motion 
is a rather uncertain 030/7 kt.  According to the majority of the 
track guidance, the system is likely to turn eastward within the 
next 12 to 24 hours.  This motion is apparently due to the system 
being embedded within a broader cyclonic gyre near the southern 
coast of Mexico.  Later in the forecast period, the system is 
expected to turn toward the northwest and move on the southern side 
of a mid-level high.  The official forecast is near the northern 
side of the track guidance model envelope.

The depression should be situated within an environment that is 
conducive for strengthening during the next few days, with very 
light vertical wind shear, and very warm sea surface temperatures.  
The official intensity forecast is near the model consensus and 
shows the system becoming a hurricane in 36 h.  It should be noted 
that the Google DeepMind and HCCA guidance call for even faster 
strengthening than shown in this initial forecast.


Key Messages:
1. Heavy rainfall associated with Tropical Depression 17-E will 
impact coastal portions of southwest Mexico this week. This rainfall 
may produce life-threatening flooding and mudslides, especially in 
areas of steep terrain.

2. Tropical Depression 17-E is forecast to strengthen and move 
closer to the southwestern Mexican coast as a major hurricane later 
this week. Although it is too soon to determine the exact location 
or magnitude of impacts associated with the system, interest in 
Mexico should closely monitor its progress and updates to the 
forecast.

 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/2100Z 14.9N 104.9W   30 KT  35 MPH
 12H  21/0600Z 15.2N 104.2W   40 KT  45 MPH
 24H  21/1800Z 15.3N 103.2W   55 KT  65 MPH
 36H  22/0600Z 15.2N 102.6W   70 KT  80 MPH
 48H  22/1800Z 15.1N 102.1W   85 KT 100 MPH
 60H  23/0600Z 15.5N 102.2W   95 KT 110 MPH
 72H  23/1800Z 16.4N 103.0W  100 KT 115 MPH
 96H  24/1800Z 18.1N 104.9W  100 KT 115 MPH
120H  25/1800Z 19.3N 107.4W  100 KT 115 MPH
 
$$
Forecaster Pasch