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Tropical Depression Three-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP032024
800 AM MST Wed Jul 31 2024
 
Over the last few hours, the convective organization has improved 
with the area of low pressure we have been monitoring a few hundred 
miles off the southwestern coast of Mexico. First-light visible 
imagery from a GOES-West meso-sector over the storm show the 
development of organized curve banding, with low-level cloud motions 
also now suggesting the presence of closed cyclonic flow. This 
improved convective structure was also seen in an earlier 1040 UTC 
SSMIS microwave pass. In addition, the latest set of subjective 
Dvorak intensity estimates were both at T2.5/35 kt from both SAB and 
TAFB. All these data suggest that the system has become a tropical 
cyclone, and advisories are being initiated at this time. The 
initial intensity for this advisory is set at 30 kt, a little under 
the Dvorak estimates given the lower objective estimates and 
earlier scatterometer data.
 
The initial estimated motion is off to the west-northwest at 
295/12-kt. This motion is expected to continue with a gentle 
turn more westward over the next few days as the system becomes 
primarily steered by a deep-layer ridge located over the 
southwestern United States. Towards the end of the forecast period, 
there could be a bit more of a weakness in this ridge on its 
western extent, potentially allowing the system to turn more 
poleward again. The initial track forecast in general sticks close 
to the consensus aids TVCE and HCCA, which favor a track that is in 
between the operational GFS and ECMWF tracks, but slightly in favor 
of the latter.
 
Intensity-wise, TD3-E might be our first system in the East Pacific 
to last longer than a couple of days, with most of the guidance 
suggesting intensification into the weekend. SHIPS guidance from 
both the GFS and ECMWF suggest the shear will remain low (less than 
15 kt) while sea-surface temperatures underneath the cyclone remain 
in the 29-30 C range over the next few days. Such a favorable 
environment could favor significant intensification once an 
inner-core becomes established. Interestingly, the 
regional-hurricane model guidance, while showing intensification, do 
not currently forecast rapid intensification. The first NHC 
intensity forecast shows more gradual intensification for the next 
day or so, followed by a somewhat faster rate, peaking the system as 
a Category 1 hurricane in 72 h, on the high end of the intensity 
guidance.  Towards the end of the forecast, the tropical cyclone 
should begin to move over cooler ocean waters, with gradual 
weakening expected to begin around day 4 or 5. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  31/1500Z 15.1N 107.2W   30 KT  35 MPH
 12H  01/0000Z 15.7N 108.9W   35 KT  40 MPH
 24H  01/1200Z 16.3N 110.9W   40 KT  45 MPH
 36H  02/0000Z 16.7N 112.9W   50 KT  60 MPH
 48H  02/1200Z 17.0N 115.0W   60 KT  70 MPH
 60H  03/0000Z 17.0N 117.1W   70 KT  80 MPH
 72H  03/1200Z 17.1N 119.0W   75 KT  85 MPH
 96H  04/1200Z 18.0N 121.5W   70 KT  80 MPH
120H  05/1200Z 18.5N 123.5W   60 KT  70 MPH
 
$$
Forecaster Papin
 
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