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Tropical Depression Two-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP022021
400 PM CDT Sun May 30 2021

The area of low pressure that the National Hurricane Center has been 
monitoring the past few days well offshore the southwestern coast of 
Mexico has continued to become better organized today and, thus, has 
now been upgraded to tropical depression status -- the second 
depression of the 2021 eastern North Pacific hurricane season. The 
initial intensity of 30 kt is based on an ASCAT-A scatterometer pass 
at 1442Z that showed several 30-32 kt surface wind vectors located 
northwest through north-northeast of the center. Dvorak satellite 
intensity estimates at 1800Z were 30 kt from TAFB and 35 kt from 
SAB, respectively, a further indication that the cyclone is just 
below tropical storm strength.

The initial motion estimate is an uncertain 300/08 kt. Although 
recent hi-resolution visible satellite imagery indicates that the 
depression has developed a tight, inner-core low-level vortex during 
the past few hours, this feature has no continuity. Thus, there is 
uncertainty in both the direction and speed of the cyclone at this 
time. However, the global and regional models show a general 
west-northwestward motion between 8-12 kt around the western 
periphery of a deep-layer ridge continuing for the next 3-5 days. 
The NHC official track forecast follows that scenario, and lies 
between the HCCA corrected consensus model to the left of the 
forecast track and the TVCE simple consensus model on the right.

The overall environment appears to be conducive for strengthening 
during the next 72 h or so based on SSTs of 29.0-29.5 deg C, 
mid-level humidity values of 70-75 percent, and low deep-layer 
vertical wind shear of 5-10 kt. The only fly-in-the- ointment is 
that both the GFS and ECMWF models show the instability decreasing 
to about half its current value by 48 hours. As a result, the 
global and regional models, and the SHIPS-LGEM model show the 
cyclone peaking at about 45 kt in 36-48 h, followed by gradual 
weakening thereafter. In contrast, the SHIPS dynamical-statistical 
model intensifies the cyclone to about 55 kt in 48-72 h, then 
followed by gradual weakening; the HCCA consensus model is similar 
to the SHIPS (DSHP) forecast. Given the aforementioned favorable 
environmental parameters, the official intensity forecast is a based 
on a blend of the HCCA and Decay-SHIPS intensity models, and lies a 
little above the IVCN intensity consensus model.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/2100Z 11.3N 103.8W   30 KT  35 MPH
 12H  31/0600Z 11.9N 105.2W   40 KT  45 MPH
 24H  31/1800Z 12.8N 107.3W   45 KT  50 MPH
 36H  01/0600Z 13.5N 109.1W   50 KT  60 MPH
 48H  01/1800Z 14.2N 110.7W   55 KT  65 MPH
 60H  02/0600Z 14.6N 111.7W   55 KT  65 MPH
 72H  02/1800Z 15.0N 112.5W   50 KT  60 MPH
 96H  03/1800Z 15.4N 113.3W   50 KT  60 MPH
120H  04/1800Z 16.0N 114.7W   45 KT  50 MPH
 
$$
Forecaster Stewart
 
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