[Tropical] Tropical Cyclone Discussion

EMWIN Server emwin at nashvilleweather.net
Wed Nov 18 02:38:38 CST 2020


WTNT41 KNHC 180838
TCDAT1

Tropical Depression Iota Discussion Number  20
NWS National Hurricane Center Miami FL       AL312020
300 AM CST Wed Nov 18 2020

Deep convection is no longer occurring near Iota's center, but
curved broken bands of convection still exist within 100 n mi in
the northern semicircle. For that reason, Iota is being maintained
as a tropical cyclone. Earlier ASCAT and ScatSat scatterometer data
between 0200-0300 UTC indicated surface winds of 30-32 kt offshore
the north-central coast of Honduras, while tropical-storm-force wind
gusts were noted in surface observations along the north coast of
Honduras. As a result, the intensity was maintained at 35 kt at the
0600 UTC synoptic time. Since then, however, winds have decreased
along the coast and offshore, which justify making Iota a 30-kt
tropical depression at the 0900 UTC advisory time. Therefore, the
Tropical Storm Warning for the northern coast of Honduras has been
discontinued.

The initial motion estimate is now 255/11 kt. Iota or its remnants
should continue moving west-southwestward across El Salvador,
possibly emerging over the eastern North Pacific Ocean as a
post-tropical cyclone before dissipation occurs by late today. At
this time, most of the available NHC model guidance does not show
regeneration over the eastern Pacific, with only the HWRF and HMON
regional models showing brief redevelopment to tropical depression
status on Thursday after Iota degenerates to a remnant low later
today. However, this is considered a low probability alternate
scenario due to unfavorable upper-level winds expected across the
eastern North Pacific.

Iota is still expected to produce very serious flash flooding and
mud slides. These hazards could result in potentially catastrophic
effects, especially when compounded upon Hurricane Eta's destruction
from a couple of weeks ago.

Key Messages:

1.  Life-threatening flash flooding and river flooding is expected
through Thursday across portions of Central America due to heavy
rainfall from Iota. Flooding and mudslides across portions of
Honduras, Nicaragua and Guatemala could be exacerbated by saturated
soils in place, resulting in significant to potentially catastrophic
impacts.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0900Z 13.7N  88.3W   30 KT  35 MPH...INLAND EL SALVADOR
 12H  18/1800Z 13.0N  89.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
 24H  19/0600Z...DISSIPATED

$$
Forecaster Stewart
This weather bulletin was brought to you by:
www.nashvilleweather.net




More information about the Tropical mailing list