Eastern Pacific Basin Tropical Cyclones

Tropical Storm Julia Forecast Discussion


000
WTPZ43 KNHC 100242
TCDEP3

Tropical Storm Julia Discussion Number  15
NWS National Hurricane Center Miami FL       EP182022
1000 PM CDT Sun Oct 09 2022

Julia's low-level center has not been easy to locate this evening
in infrared satellite imagery, but a couple of SSMIS microwave
overpasses between 2300-2331 UTC suggest that the center was
located very close to the northwestern coast of Nicaragua.  A band
of deep convection has developed to the southeast of the estimated
center but it lacks significant curvature.  Assuming some additional
weakening occurred before Julia exited the coast, the initial
intensity has been reduced to 35 kt which is in line with the
latest Dvorak estimate from TAFB.  However, there is larger than
normal uncertainty regarding Julia's initial intensity.  Hopefully,
scatterometer data will provide some clarity on the intensity of
the cyclone overnight.

Since the northern portion of Julia's circulation is forecast to
continue interacting with the mountainous terrain of central
America, additional weakening is expected over the next 12 to 24
hours. Forecast wind fields from the GFS, ECMWF, and UKMET indicate
that the circulation is likely to lose definition over the next 12 
to 18 hours, and by 24 hours Julia is forecast to dissipate as it
is absorbed within a broad surface trough/low associated with a
Gulf of Tehuantepec gap wind event.

Julia's appears to be moving between west and west-northwest at
about 13 kt. A west-northwestward motion around the southwestern
portion of a mid-level ridge over the southeastern Gulf of Mexico
should continue until dissipation occurs. The NHC track forecast is
again on the northern side of the model envelope, close to the GFS
and ECMWF model fields.  After 24 hours, the model trackers latch
on to the vorticity associated with the broad circulation mentioned
above, and not Julia itself.


Key Messages:

1. Julia is forecast to move near the coasts of northwestern
Nicaragua, Honduras, and El Salvador through Monday, where tropical
storm warnings are in effect.  Tropical-force-winds are also
possible on Monday along the Pacific coast of Guatemala, where a
tropical storm watch is in effect.

2. Life-threatening flash flooding and mudslides are expected across
portions of Central America into Monday.  Flash flooding is
anticipated across the Isthmus of Tehuantepec in Mexico early this
week.


FORECAST POSITIONS AND MAX WINDS

INIT  10/0300Z 12.8N  88.1W   35 KT  40 MPH
 12H  10/1200Z 13.4N  90.1W   30 KT  35 MPH
 24H  11/0000Z...DISSIPATED

$$
Forecaster Brown



Source link