000
WTPZ42 KNHC 250233
TCDEP2

Tropical Storm Greg Discussion Number  31
NWS National Hurricane Center Miami FL       EP072017
800 PM PDT Mon Jul 24 2017

The cloud pattern of Greg has changed little during the last
several hours.  The low-level center of the storm remains covered
up by an area of deep convection that has increased in intensity
during the past few hours.  The latest Dvorak classifications
are largely unchanged from earlier, and the initial wind speed
estimate remains 40 kt for this advisory.  This intensity estimate
is also in fairly close agreement with the earlier scatterometer
data.

Greg has made the expected turn to the west-northwest on the south
side of a low- to mid-level ridge.  The models suggest that Greg
should move west-northwestward to northwestward during the
next couple of days as the ridge to the north of the system weakens
a little.  A turn to the west and then west-southwest is expected in
2 to 3 days when Greg becomes a shallow system and is steered by the
low-level trade wind flow. The NHC track forecast is a tad to the
north of the previous one, trending toward the latest model
consensus aids.

The tropical storm is still over relatively warm 27 deg C waters
and in a low wind shear environment.  The environment along the
projected path of Greg is expected to become hostile during
the next couple of days, with the cyclone forecast to move into a
progressively drier air mass and over waters cooler than 26 deg C
beginning in about 24 h.  In addition, a significant increase in
northwesterly wind shear is expected to begin in 36 to 48 h.  These
unfavorable conditions should cause a steady weakening trend, and
Greg is forecast to become a remnant low by 72 h.  The NHC intensity
forecast is identical to the previous one and in line with the bulk
of the model guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 14.8N 134.9W   40 KT  45 MPH
 12H  25/1200Z 15.4N 135.9W   35 KT  40 MPH
 24H  26/0000Z 16.3N 137.3W   35 KT  40 MPH
 36H  26/1200Z 17.1N 138.7W   35 KT  40 MPH
 48H  27/0000Z 17.5N 140.2W   30 KT  35 MPH
 72H  28/0000Z 17.0N 143.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  29/0000Z 16.0N 146.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  30/0000Z 15.0N 148.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi