000
WTPZ44 KNHC 040903
TCDEP4

Tropical Storm Ramon Discussion Number   1
NWS National Hurricane Center Miami FL       EP192017
400 AM CDT Wed Oct 04 2017

The small low pressure area located just south of the coast of
southern Mexico has been producing persistent convection for about
12 hours.  Although the convection is confined to the western
portion of the circulation due to strong easterly shear, it has
enough organization for the system to be classify as a tropical
cyclone.  Scatterometer data from 0410 UTC revealed a small area
of 35-40 kt winds to the west of the center, so advisories are
being initiated on a 40-kt tropical storm, the seventeenth tropical
storm of the 2017 eastern Pacific hurricane season.  Strong
easterly shear is forecast to persist over Ramon during the next
during the next few days, which is likely to prevent strengthening
of the small tropical storm.  The ECMWF and GFS weaken the cyclone
over the next day or so, although both models show some interaction
with another disturbance farther west in a couple of days.  The NHC
forecast is of low confidence and calls for no change in strength
throughout the forecast period.  An alternate scenario is for Ramon
to move closer to the coast of Mexico and dissipate within the next
2-3 days.

Ramon is moving westward or 270/8 kt to the south of a deep layer
ridge over the northern Gulf of Mexico.  The ridge is forecast to
build westward over northern Mexico during the next few days, which
should cause Ramon to move westward at a slightly faster forward
speed.  Later in the period, Ramon is forecast to reach the western
portion of the ridge and turn northwestward.  Although most of the
model guidance agrees with this general scenario, there is a fair
amount of spread in the track models.  The GFS and HWRF show a
faster westward motion while the ECMWF is much slower.  The UKMET
is the outlier by taking Ramon eastward toward central America as a
low pressure area develops over the western Caribbean. Given the
large spread in the guidance, the NHC track forecast shows a slower
westward track and is close to the GFS and ECMWF ensemble means.
The confidence in the track forecast is quite low and interests
along the southern coast of Mexico should monitor the progress of
this system.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 14.3N  96.0W   40 KT  45 MPH
 12H  04/1800Z 14.3N  97.3W   40 KT  45 MPH
 24H  05/0600Z 14.3N  99.5W   40 KT  45 MPH
 36H  05/1800Z 14.3N 102.0W   40 KT  45 MPH
 48H  06/0600Z 14.4N 104.3W   40 KT  45 MPH
 72H  07/0600Z 14.5N 107.5W   40 KT  45 MPH
 96H  08/0600Z 14.5N 111.0W   40 KT  45 MPH
120H  09/0600Z 15.5N 112.5W   40 KT  45 MPH

$$
Forecaster Brown