ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM PATRICIA DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202015
1000 AM CDT WED OCT 21 2015

Conventional and microwave satellite data show that Patricia
remains poorly organized.  The low-level circulation is elongated
from north to south, and there is little evidence of a tight inner
core.  While the convection is vigorous, it is occurring mainly in
an almost linear area west and south of the center.  The latest
satellite intensity estimates are unchanged since the previous
advisory, so the initial intensity remains 35 kt.

Patricia is moving faster toward the west with an initial motion of
270/10.  There is no change to the track forecast philosophy.  The
tropical cyclone is expected to initially move westward to
west-northwestward on the south side of a low- to mid-level ridge
over the Gulf of Mexico.  After about 24 hours, Patricia is expected
to turn northwestward and northward between the ridge and a deep-
layer trough over northwestern Mexico and the adjacent northeastern
Pacific.  The model guidance is in excellent agreement with this
scenario and forecasts landfall along the coast of southwestern
Mexico between 48-72 hours.  The new forecast track is similar to,
but a little faster than, the previous track, and it lies in the
middle of the tightly clustered track guidance.

Continued light shear and warm sea surface temperatures are
favorable conditions for Patricia to strengthen if the storm can
overcome its current disorganized condition.  Based on the premise
that this will happen, the intensity forecast is identical to that
of the previous advisory in calling for the cyclone to become a
hurricane in about 36 hours and continue strengthening through
landfall.  Several of the guidance models forecast a higher peak
intensity than the official, and rapid intensification remains a
possibility given the favorable environment.  After landfall,
Patricia should quickly weaken and dissipate over the mountains of
western Mexico.

There are no changes to the watches for the coast of Mexico at this
time.  Warnings my be required for portions of the watch area later
today or tonight.

It should be noted that several of the global models develop a low
pressure area over the northwestern Gulf of Mexico in four to five
days.  At this time, it appears that this system will be a
non-tropical low that absorbs the remnants and moisture of Patricia
moving northeastward across Mexico.

FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 12.9N  97.5W   35 KT  40 MPH
 12H  22/0000Z 13.4N  99.1W   40 KT  45 MPH
 24H  22/1200Z 14.5N 101.3W   50 KT  60 MPH
 36H  23/0000Z 15.7N 103.1W   65 KT  75 MPH
 48H  23/1200Z 17.3N 103.8W   80 KT  90 MPH
 72H  24/1200Z 21.5N 104.0W   45 KT  50 MPH...INLAND
 96H  25/1200Z...DISSIPATED

$$
Forecaster Beven

NNNN