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TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012015
300 AM MDT THU MAY 28 2015

Deep convection has become increasingly consolidated and organized
in association with an area of low pressure located well to the
southwest of the coast of Mexico.  Enough convective banding has
formed to yield Dvorak estimates of T2.0/30 kt from TAFB and
T1.5/25 kt from SAB, and a 0459 UTC ASCAT-B pass showed maximum
winds near 30 kt.  The ASCAT data also showed that a center of
circulation appeared sufficiently well defined, allowing the
designation of the low as a 30-kt tropical depression at this time.

The depression lies to the south of a mid-level ridge which extends
from central Mexico west-southwestward over the eastern Pacific, and
its initial motion is 295/13 kt.  Global model fields show that the
ridge should remain firmly in place, especially to the northwest of
the depression, during the next several days.  This should force the
cyclone to slow down considerably and move north-northwestward from
days 2 through 5.  There is good agreement among the track models
during the first 3 days of the forecast.  By days 4 and 5, however,
there is more uncertainty with the GFDL and HWRF models showing a
northward motion while the GFS and ECMWF show a northwestward
motion.  The NHC track forecast currently lies closest to the GFS
model and the TVCE multi-model consensus.  Regardless of the exact
track, the cyclone is expected to stay well to the southwest of
Mexico during the entire forecast period.

Relatively low shear and warmer-than-normal sea surface temperatures
should support intensification during the next 3 days or so.  Of the
intensity guidance, the SHIPS model is the most aggressive, making
the cyclone a hurricane by 36 hours with a peak intensity near 90 kt
in 2-3 days.  The official intensity forecast isn't quite that
aggressive, but it does lie slightly above the ICON intensity
consensus.  Rapid intensification isn't out of the question, and in
fact the RI guidance suggests that it may be likely during the next
24 hours.  In light of that, some upward adjustment to the official
forecast may be needed in subsequent advisories.  Weakening should
begin by day 4 once the cyclone reaches colder water.

Note that beginning this year, Tropical Cyclone Public Advisories,
Discussions, and Updates for the eastern North Pacific will now use
different time zones depending on the cyclone's current location, as
follows:

Central Time:  east of 106.0W
Mountain Time: 106.0W to 114.9W
Pacific Time:  115.0W westward

FORECAST POSITIONS AND MAX WINDS

INIT  28/0900Z 11.0N 110.4W   30 KT  35 MPH
 12H  28/1800Z 11.7N 111.5W   40 KT  45 MPH
 24H  29/0600Z 12.6N 112.8W   50 KT  60 MPH
 36H  29/1800Z 13.4N 113.5W   60 KT  70 MPH
 48H  30/0600Z 14.2N 114.0W   70 KT  80 MPH
 72H  31/0600Z 16.0N 115.0W   80 KT  90 MPH
 96H  01/0600Z 17.5N 116.0W   70 KT  80 MPH
120H  02/0600Z 19.0N 117.0W   60 KT  70 MPH

$$
Forecaster Berg

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