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Tropical Storm Eta Discussion Number  17
NWS National Hurricane Center Miami FL       AL292020
300 PM CST Wed Nov 04 2020
 
Eta continues to weaken as it moves from Nicaragua into Honduras.  
There is little convection left near the center, and the strongest 
convection remains in bands well removed from the center.  As 
before, there are no wind observations available near the center 
of Eta at this time, so the initial intensity is reduced to a 
uncertain 35 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 24 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 or northwestward on the eastern side of the trough as 
it cuts off into a closed low.  The track guidance remains in 
reasonable agreement with this scenario,  However, there remains 
some spread on when and where the various turns will occur, and 
there has also been an eastward shift in the guidance envelope after 
36 h.  The new forecast track is shifted to the east of the previous 
track after 36 h, and at 72 and 96 h it lies a little to the west of 
the various consensus models,
 
Eta will continue to weaken while it crosses 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 suggested by the UKMET, 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 that follows the general trend of the model 
guidance.  However, the intensity forecast again 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 Monday 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, the Cayman Islands and western Cuba.
 
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  04/2100Z 13.9N  85.7W   35 KT  40 MPH...INLAND
 12H  05/0600Z 14.2N  86.7W   30 KT  35 MPH...INLAND
 24H  05/1800Z 15.1N  87.8W   25 KT  30 MPH...POST-TROP/INLAND
 36H  06/0600Z 16.5N  87.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  06/1800Z 17.7N  86.7W   30 KT  35 MPH...TROPICAL CYCLONE
 60H  07/0600Z 18.8N  84.8W   40 KT  45 MPH
 72H  07/1800Z 20.5N  82.6W   45 KT  50 MPH
 96H  08/1800Z 24.0N  80.5W   50 KT  60 MPH
120H  09/1800Z 25.5N  82.5W   50 KT  60 MPH
 
$$
Forecaster Beven
 
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