Official Discussion issued by the National Hurricane Center

Gamma (AL252020) DATA RELEASED: 10/3/2020 4:00:00 PM UTC

Copy of official data

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 


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.


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