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Tropical Storm Eta Discussion Number  16
NWS National Hurricane Center Miami FL       AL292020
900 AM CST Wed Nov 04 2020

Eta is weakening as it moves across northern Nicaragua,  Most of the 
inner core convection has weakened, and the strongest convection is 
now in bands well removed from the center.  There are no wind 
observations available near the center of Eta at this time, so the 
initial intensity is reduced to a uncertain 45 kt.

The initial motion is westward or 275/6.  A mid-level ridge to the 
north of the cyclone should steer it on a generally 
west-northwestward track during the next 36 h or so.  After that 
time, a mid- to upper-level trough moving over the central and 
eastern Gulf of Mexico is expected to cause Eta or is remnants to 
turn northward and then northeastward,  Then, by 120 h, the cyclone 
is likely to move northward on the eastern side of the trough. While 
the track guidance is in reasonable agreement with this scenario, 
there is some spread on when and where the various turns will occur, 
and thus there is a fair amount of uncertainty about what parts of 
Cuba and Florida the center may pass near or over.  The new forecast 
track is similar to the previous track and lies near the various 
consensus models.

Eta will continue to weaken while it crosses Nicaragua and Honduras, 
and it is expected to decay to a remnant low before it reaches the 
Gulf of Honduras or the northwestern Caribbean Sea.  Re-development 
is expected once the center is over the water.  However, interaction 
with the aforementioned trough could result in a structure that is 
more subtropical or hybrid, as indicated by the GFS/HWRF, than a 
classical tropical cyclone, as suggested by the ECMWF.  The new 
intensity forecast will follow the previous forecast and go with a 
gradual intensification in the expectation that the GFS scenario is 
more likely to verify,  However, the intensity forecast lies a 
little below the intensity consensus.
 
Although it is weakening, Eta will continue to produce heavy 
rainfall and flooding over portions of Central America.
 
 
Key Messages:
 
1. Through Sunday morning, heavy rainfall from Eta will lead to 
catastrophic, life-threatening flash flooding and river flooding 
across portions of Central America, along with landslides in areas 
of higher terrain.  Flash and river flooding is also possible across 
Jamaica, southeast Mexico, El Salvador, southern Haiti, and the 
Cayman Islands.
 
2. Eta is forecast to regain tropical storm strength before it
moves across portions of Cuba and approaches southern Florida this
weekend.  While it is too soon to determine the exact timing,
magnitude, and location of possible impacts from wind and rainfall,
interests in Cuba, southern Florida and the Florida Keys should
monitor the progress of Eta through the week.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/1500Z 13.9N  85.2W   45 KT  50 MPH...INLAND
 12H  05/0000Z 14.1N  86.3W   30 KT  35 MPH...INLAND
 24H  05/1200Z 14.9N  87.7W   25 KT  30 MPH...INLAND
 36H  06/0000Z 16.0N  88.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  06/1200Z 17.0N  88.2W   30 KT  35 MPH...OVER WATER
 60H  07/0000Z 18.0N  86.4W   35 KT  40 MPH
 72H  07/1200Z 19.6N  84.4W   40 KT  45 MPH
 96H  08/1200Z 23.0N  81.5W   45 KT  50 MPH
120H  09/1200Z 25.0N  82.0W   50 KT  60 MPH
 
$$
Forecaster Beven
 
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