Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
210 PM EDT Thu Oct 16 2025

Forecast Bulletin 16 October 2025 at 1800 UTC:

Synopsis:

An Atlantic cold front will continue to bring rainfall for much of
the Greater Antilles over the next couple of days, before the
arrival of another cold front over the weekend. In Mexico, the
development of a low pressure system in association with a monsoon
trough will bring modest precipitation to the southern coast of
Mexico late in the week and into the weekend. The presence of the
aforementioned monsoon trough over the south coast of Costa Rica
and Panama is expected to bring heavy precipitation to the region
over the next couple of days, while the arrival of a plume of
moisture is anticipated to move into Honduras and Nicaragua late
in the weekend. In South America, seasonable convection caused by
diurnal and local effects is expected to continue throughout the
forecast period.

The Bahamas and Caribbean:

A cold front in the Atlantic will remain in place, extending into
the island of Hispaniola, Jamaica, and the Yucatan Peninsula.
While convection is expected to remain disorganized, locally heavy
precipitation is forecast in parts of the Dominican Republic,
Haiti, Jamaica, southern Cuba and the Leeward Islands. For
Hispaniola and Jamaica in particular, orographic enhancement will
aid in yielding higher totals, with 25-50mm expected for
Hispaniola, and 20-40mm expected in Jamaica on Friday, with
locally higher amounts possible.  Additionally, there is a slight
risk of severe weather and hail in the Leeward islands today, and
in the Virgin Islands on Friday.

Over the weekend, the cold front is expected to begin dissipating,
but only due to the arrival of another cold front on Saturday,
associated with the same system. This front is also expected to
remain in place for an extended period, but given there will be
little moisture associated with it, precipitation in the Bahamas
early in the weekend is expected to remain light and localized.
With the influence of the previous front, however, the islands of
Hispaniola and Jamaica should expect to receive similar amounts of
precipitation, again largely due to continued diurnal and
orographic effects.

Mexico and Central America:

A developing low pressure system south of Mexico associated with
the presence of a monsoon trough will be of interest over the next
few days for potential impacts in the south coast of Mexico. The
National Hurricane Center is currently monitoring this system and
has given it a 60% chance of tropical cyclone development over the
next seven days. While any development is expected to remain
offshore, onshore moisture flow on the eastern side of the low is
expected to provide fuel for light to locally moderate
precipitation on the south coast of Mexico late this week and into
the weekend. Precipitation totals are currently forecast to be
modest, reaching a maximum of 20-35mm on Saturday.

In the Yucatan Peninsula, a stationary front will continue to
impact the region over the next few days, bringing moderate to
locally heavy precipitation. The front is expected to begin
dissipating late in the weekend, but until then, daily
precipitation maxima of 15-30mm are expected.

The presence of the monsoon trough in the south coast of
Guatemala, Honduras, El Salvador, and Costa Rica will bring daily
precipitation to the region for the next few days. Easterly
moisture flow will enter the region from the Caribbean Sea, and
with orographic enhancement, high precipitation totals of up to
30-60mm are expected for this area on Saturday, with locally
higher amounts possible. The heaviest precipitation is expected to
occur in Costa Rica given the significant amounts of moisture flow
into the southern coast.

Towards the end of the weekend and early next week, an upper level
inverted trough reflected in the lower levels is expected to
develop off the east coast of Nicaragua and Costa Rica. In the
low-levels, a closed circulation in the form of the Panamanian low
will develop, and the easterly influx of moisture is expected to
increase. This will bring heavy precipitation to the east coast of
Nicaragua and Honduras, while continuing to bring precipitation to
Costa Rica and Panama.

Tropical South America:

Precipitation in tropical South America is expected to continue to
be caused by diurnal and local effects. Weak but moist low-level
westerly flow will continue entering the west coast of Colombia,
where heavy precipitation of up to 25-50mm is expected today and
Friday. In central tropical South America, low-level moisture will
continue to move westward from the Amazon, and with local and
diurnal effects, along with little organization in the mid and
upper levels, daily localized convection is expected throughout
the forecast period.

Over the weekend, the arrival of a tropical wave, currently
located at 47W, along with enhanced moisture from the ITCZ, will
bring precipitation to the northern portions of South America and
the southern Windward Islands. Heaviest precipitation is expected
to occur in Trinidad and Tobago, the northern parts of Venezuela
and Guyana, with a maximum of 20-45mm expected on Saturday.



Positions of Tropical/Easterly Waves Initialized at 12 UTC
TYP SOF INIT 17/00 17/12 18/00 18/12 19/00 19/12 20/00
TW  14N  33W   37W   41W  45W  49W   52W   55W   58W 
TW  11N  47W   51W   55W  59W  63W   66W   69W   72W

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

Blanco-Alcala...(WPC)