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Tropical Storm Eta Discussion Number   5
NWS National Hurricane Center Miami FL       AL292020
400 PM EST Sun Nov 01 2020
 
Eta has continued to quickly become better organized today with an 
increase in banding and the development of a central dense overcast 
feature.  A NOAA Hurricane Hunter aircraft that has provided a 
couple of center fixes this afternoon has found a strengthening 
tropical storm.  The aircraft has reported a minimum pressure of 
992 mb and a 30 n-mi-wide eye that is open to the southwest.  A 
blend of the SFMR and flight-level wind data support an initial wind 
speed of 55 kt for this advisory.  Given the much improved 
inner-core structure as reported by the reconnaissance aircraft and 
the favorable environmental conditions of low vertical wind shear 
and high ocean heat content, additional strengthening is likely.  
The intensity guidance is much higher this cycle, and the various 
rapid intensification models show a much more significant chance of 
rapid strengthening over the next 24 to 36 hours.  The DTOPS model 
indicates a 71 percent chance of a 30-kt increase in wind speed over 
the next 24 hours, while the SHIPS Rapid Intensification Index shows 
a 53 percent chance of a 45-kt increase over the next 36 hours. 
Based on the higher initial intensity and the more bullish 
guidance, the NHC intensity forecast has been increased and 
essentially calls for rapid strengthening until Eta reaches the 
coast of Central America.  Once inland, Eta should quickly weaken 
over the mountainous terrain of Nicaragua and Honduras.
 
Eta is still moving steadily westward or 270 degrees at about 14
kt.  A westward motion at a somewhat slower forward speed is
expected tonight.  On Monday, Eta is forecast to turn southwestward
at a slower forward speed when a mid-level ridge builds to the
north and northwest of the cyclone.  Eta is forecast to move inland 
over northeastern Nicaragua within the Hurricane Warning area 
Monday night or early Tuesday. The dynamical models are in 
relatively good agreement through about 72 hours, expect for the 
HWRF which shows a more northern track and keeps Eta offshore for 
much of the period.  This solution is considered an outlier at this 
time, and the NHC track is in good agreement with the various 
global models and the HFIP corrected consensus model.  Some model 
solutions still suggest Eta or its remnants will re-emerge over the 
northwestern Caribbean Sea at or beyond day 5.  The new NHC 5-day 
position is still inland near the Gulf of Honduras close to the 
various consensus aids, but large uncertainty exists in the 
forecast at that time range due to the large spread in the track 
guidance. 

Key Messages:
 
1. Eta is forecast to strengthen into a hurricane tonight, and 
additional strengthening is forecast before it reaches the 
northeastern coast of Nicaragua Monday night or early Tuesday, where 
a Hurricane Warning is in effect. A Tropical Storm Warning is in 
effect for a portion of the northeastern coast of Honduras. 

2. Through Friday afternoon, heavy rainfall from Eta will lead to 
significant, 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, Southern Haiti, and the Cayman Islands.

3. A life-threatening storm surge, along with damaging waves, is 
expected along portions of the northeastern coast of Nicaragua near 
and to the north of where the center makes landfall.  Water 
levels could reach as high as 10 to 15 feet above normal tide levels 
in some parts of the hurricane warning area. Preparations to protect 
life and property should be rushed to completion. 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  01/2100Z 14.9N  78.9W   55 KT  65 MPH
 12H  02/0600Z 15.0N  80.5W   65 KT  75 MPH
 24H  02/1800Z 14.7N  82.1W   80 KT  90 MPH
 36H  03/0600Z 14.2N  83.1W   95 KT 110 MPH
 48H  03/1800Z 14.0N  83.8W   75 KT  85 MPH...INLAND
 60H  04/0600Z 14.0N  84.7W   50 KT  60 MPH...INLAND
 72H  04/1800Z 14.1N  85.7W   35 KT  40 MPH...INLAND
 96H  05/1800Z 14.7N  88.0W   25 KT  30 MPH...INLAND
120H  06/1800Z 15.5N  88.5W   25 KT  30 MPH...INLAND
 
$$
Forecaster Brown
 
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