414
FXCA20 KWBC 091938
PMDCA

Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
338 PM EDT Thu Oct 09 2025

Forecast Bulletin 9 October 2025 at 1930 UTC:

Synopsis:

The ongoing low-level induced trough event on the eastern portions
of Mexico will bring heavy rain to Veracruz, Tamaulipas, and San
Luis Potosi today and Friday, before beginning to subside on
Saturday. On the south coast of Mexico, Tropical Depression
Raymond has formed off the coast of Guerrero/Oaxaca, and an influx
of moisture and precipitation is expected in Guerrero, Oaxaca, and
Michoacan over the next couple of days. Later in the weekend,
Raymond is expected to bring heavy rainfall to the northwest
portions of Mexico, as it gets taken in an upper level trough in
the southwest United States. In the Bahamas and Cuba, the
development of a low pressure system on the divergent side of an
upper level trough will bring heavy rain and possible severe
weather over the weekend. Further south in Central America
moisture and cyclonic circulation associated with the monsoon
trough will bring onshore flow, yielding precipitation in southern
Guatemala, El Salvador, as well as further south in Costa Rica. In
Tropical South America, high moisture content in the Lake
Maracaibo region will make its way into the valleys and bring
heavy and localized precipitation on Friday and into the weekend.

Mexico and Central America:

The low-level induced trough is expected to continue bringing
significant amounts of precipitation to the east coast of Mexico,
including Veracruz, Tamaulipas, and San Luis Potosi today and
Friday, before beginning to dissipate early in the weekend.
Significant amounts of moisture will continue to be injected into
the region, especially today, and coupled with a strong low-level
jet and orographic enhancement, will continue to bring heavy rain.
The most notable precipitation is expected to occur today through
Friday evening. Storm total precipitation amounts of up to
100-150mm are expected in southern Tamaulipas, while parts of San
Luis Potosi and northern portions of Veracruz will see totals up
to 150-200mm, with locally higher amounts over 200mm possible.
Rain is then forecast to continue in this region thereafter, on
Sunday, but is not expected to be as significant.

Further south in Mexico, Tropical Depression Raymond has formed
off the southern coast of Mexico, south of Oaxaca/Guerrero.
Raymond is currently forecast to remain offshore, with a parallel
track to the southwest coast of Mexico. Low-level moisture and
winds associated with the system are also expected to flow mostly
parallel, with some onshore flow on the eastern portion of the
system. This will yield high precipitation totals today into
Friday morning in this area, with total precipitation amounts of
30-60mm expected. Later into the weekend, associated moisture will
make its way into the northwest of Mexico, including Sinaloa and
Nayarit, as the system makes its way to the Baja California
Peninsula.

Late in the weekend and early next week, moisture from Raymond
will make its way into the northwest portions of Mexico. This
could prove to be impactful for Sonora on Sunday and Monday,
bringing heavy precipitation to the region. Interests in Sonora
should continue monitoring the latest forecasts of Raymond late
into the weekend.

The presence of the monsoon trough will aid in bringing an
easterly and onshore flow of moisture to Honduras and Nicaragua.
Additional support from the cold front in Cuba will aid in the
production of precipitation to this area towards the end of the
weekend.

The Bahamas and Caribbean:

A deep upper-level trough in the central United States is expected
to continue digging far south, all the way to the Yucatan
Peninsula. With Cuba and the Bahamas on the eastern side of the
trough, upper-level divergence will be enhanced in this region. A
broad system of low pressure will then propagate northeastward
from northwest Cuba early on Friday, and is forecast to move
through the Bahamas early in the weekend. As the low develops, a
warm front associated with Hurricane Jerry, and a cold front from
the United States will merge, with the cold front becoming the
dominant boundary. The cold front is then expected to make its way
far south into Cuba and the Bahamas over the weekend. This setup
will bring heavy precipitation beginning today and lasting through
the forecast period for the western parts of Cuba and the northern
Bahamas. Precipitation will be heaviest on Saturday, with 30-60mm
expected in the Bahamas, and 25-50mm expected in Cuba.
Additionally, there is a slight risk of severe weather for the
Bahamas and Cuba on Friday and Saturday.

In the Lesser Antilles, Tropical Storm Jerry is forecast to bring
heavy rainfall to the Leeward Islands, the Virgin Islands, and
Puerto Rico, as it continues its track northwestward. Southerly
remnant moisture flow associated with Jerry is then expected to
continue moving through this region and precipitation is expected
to continue after its departure on Sunday. Heaviest precipitation
is anticipated to occur on Saturday, with up to 25-50mm expected
in the northern Leeward Islands.

Tropical South America:

Cyclonic circulation from the monsoon trough located just north of
South America will aid in supplying moisture to the northwest
portions of South America. This incoming moisture will flow in
from the west and interact with the topography in northern
Colombia and western Venezuela, and will bring heavy precipitation
daily throughout the forecast period.

In the west coast of Colombia, a strong low-level westerly flow of
long fetch moisture is expected to continue moving into the
region, bringing precipitation of up 30-60mm daily throughout the
forecast period. With weak upper-level easterly flow being present
and bringing in moisture from the Amazon, the lower-level
interaction will be conducive to high precipitation totals on the
coast.

Low-level easterly moisture flow is also expected in the central
portions in South America. This moisture will converge in the
mountainous regions in northwest Brazil, Peru, Ecuador, southeast
Venezuela, and east Colombia, and will aid in the development of
daily localized convection and precipitation throughout the
forecast period.



Positions of Tropical/Easterly Waves Initialized at 12 UTC
TYP SOF INIT 10/00 10/12 11/00 11/12 12/00 12/12 13/00 13/12
EW  25N  36W   40W   44W  48W   52W   55W   58W   61W   64W
TW  13N  78W   80W   82W  83W   Diss----------


For the latest available charts please visit:
https://www.wpc.ncep.noaa.gov/international/crb_day1-3.shtml

Blanco-Alcala...(WPC)
$$