477
WTNT45 KNHC 032037
TCDAT5

Tropical Storm Gamma Discussion Number 6
NWS National Hurricane Center Miami FL AL252020
400 PM CDT Sat Oct 03 2020

Surface observations from the Yucatan Peninsula along with
high-resolution visible satellite imagery indicated that the center
of Gamma made landfall in the vicinity of Tulum, Mexico, shortly
before 1700 UTC. Earlier aircraft observations and pressure
measurements from Tulum showed that the system was very near
hurricane strength when it made landfall. A ragged eye appeared in
the visible images shortly after the center crossed the coast, but
that feature has since become obscured. Since Gamma has likely
been slowly weakening while moving over land, the current intensity
has been set to 55 kt. Continued gradual weakening is likely into
Sunday while the center either moves over land or interacts with
nearby land. Some re-strengthening is expected to begin by
Monday, but the numerical guidance is not very enthusiastic about intensification over the Gulf, probably due to the combination of
drier air and the interaction with another low pressure system to
the east. The official intensity forecast is not much different
from the model consensus.

Gamma has been moving northwestward, but it is expected to turn north-northwestward while moving near and into a weakness in the
subtropical ridge over the next day or so. The global models
predict that a trough to the north of the tropical cyclone will
lift northeastward and bypass Gamma. In a couple of days, a ridge
is forecast to build back, albeit weakly, across the Gulf of
Mexico. This is expected to cause the system to turn westward to
southwestward over the latter part of the forecast period. The
more reliable global models show the system meandering over the
southern Bay of Campeche in 4 to 5 days, and so does the official
forecast.


KEY MESSAGES:

1. Gamma is expected to produce heavy rainfall for several days over
portions of southeastern Mexico, the Yucatan Peninsula, Central
America, and far western Cuba. This rainfall could result in
life-threatening flash flooding and mudslides, particularly in the
mountainous regions of southeastern Mexico and Central America.

2. Even though Gamma has moved inland, tropical storm conditions
will continue along the east coast of the Yucatan Peninsula through
this evening and are expected to spread along the north coast within
the Tropical Storm Warning area tonight and on Sunday.


FORECAST POSITIONS AND MAX WINDS

INIT 03/2100Z 20.7N 87.7W 55 KT 65 MPH...INLAND
12H 04/0600Z 21.3N 88.0W 45 KT 50 MPH...INLAND
24H 04/1800Z 22.0N 88.2W 40 KT 45 MPH...OVER WATER
36H 05/0600Z 22.1N 88.4W 40 KT 45 MPH
48H 05/1800Z 22.0N 89.1W 45 KT 50 MPH
60H 06/0600Z 21.6N 90.4W 50 KT 60 MPH
72H 06/1800Z 21.0N 91.5W 50 KT 60 MPH
96H 07/1800Z 20.0N 92.0W 45 KT 50 MPH
120H 08/1800Z 20.0N 93.0W 40 KT 45 MPH

$$
Forecaster Pasch
--- SBBSecho 3.11-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (21:1/175)