[Tropical] Tropical Cyclone Discussion

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WTNT44 KNHC 030259
TCDAT4

Hurricane Eta Discussion Number  10
NWS National Hurricane Center Miami FL       AL292020
1000 PM EST Mon Nov 02 2020

An Air Force Reserve reconnaissance aircraft has found that Eta has
explosively deepened into a strong category 4 hurricane with maximum
sustained winds of 130 kt and a minimum central pressure of 927 mb.
Eta has maintained a small 10-nmi-wide eye that is evident in
satellite imagery and on the San Andreas, Colombia, weather radar.
The radar data also suggest that concentric eyewalls may be forming,
which would be an indication of the onset of an eyewall replacement
cycle (ERC) and a capping of Eta's intensity and also an end to the
rapid intensification cycle of the past 36 hours. The initial
intensity of 130 kt kt is based on 700-mb flight-level winds of 137
kt and SFMR surface winds of 130 kt. Some additional strengthening
is expected, and Eta could become a category 5 hurricane before
landfall occurs. After landfall, Eta should quickly weaken while it
moves over the mountainous terrain of Central America.

Eta has slowed and is now moving southwestward or 245/06 kt. There
is no significant change to previous track forecast reasoning. A
mid-level ridge over the south-central United States should steer
Eta west-southwestward toward the coast of Nicaragua with the
hurricane making landfall early Tuesday.  After landfall, Eta should
turn westward and then west-northwestward, and move across Central
America through Thursday. Eta's low-level circulation may not
survive its passage over the mountainous terrain of Central America,
but most of the global models continue to depict a cyclone or its
remnants moving over the northwestern Caribbean Sea by late-week and
into the weekend. Therefore, the new NHC track forecast continues to
show the system emerging over the northwestern Caribbean late in the
period, although this portion of the track forecast remains
uncertain.

Since Eta is likely to be a very slow-moving system after it makes
landfall in Central America, torrential rains and flooding will be
a major threat.

Key Messages:

1. Catastrophic wind damage is expected where Eta's eyewall moves
onshore along the northeastern coast of Nicaragua tonight or early
Tuesday.  Tropical storm force winds are beginning to reach the
coast within the Hurricane Warning area in Nicaragua, and residents
there should have completed their preparations.  A Tropical Storm
Warning is also in effect for the northeastern coast of Honduras.

2. A catastrophic and life-threatening storm surge, along with
destructive waves, are 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 14 to 21 feet above
normal tide levels in some parts of the hurricane warning area.
Preparations to protect life and property should now be complete.

3. Through Friday evening, heavy rainfall from Eta will likely
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.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0300Z 14.1N  82.7W  130 KT 150 MPH
 12H  03/1200Z 13.9N  83.3W  140 KT 160 MPH
 24H  04/0000Z 13.9N  84.0W   90 KT 105 MPH...INLAND
 36H  04/1200Z 13.9N  85.0W   45 KT  50 MPH...INLAND
 48H  05/0000Z 14.3N  86.3W   30 KT  35 MPH...INLAND
 60H  05/1200Z 14.8N  87.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  06/0000Z 15.4N  88.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  07/0000Z 16.8N  87.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  08/0000Z 17.9N  85.3W   40 KT  45 MPH

$$
Forecaster Stewart
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