Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
226 PM EST Wed Jan 14 2026

Forecast Bulletin 14 January 2026 at 1930 UTC:

On Wednesday, a potent upper level trough is advancing south and
east, over the south United States during the day on Wednesday,
interacting with the Subtropical Jet situated over north Mexico
and the Bahamas. With the upper level trough, a potent cold front
is also moving southward and reaches northeast Mexico by Wednesday
night. As the interaction of the upper level system is expected
from Wednesday into early Thursday, the associated divergence is
expected to sustain the frontal remnants that remained from the
central Atlantic into Cuba, and the Yucatan Peninsula and sustain
a weak frontal boundary over the region into early Thursday
morning. Due to the low amount of moisture in the region, the
areas with the highest precipitation maxima are expected in the
northern Bahamas and in south Veracruz and Tabasco. The Bahamas
can expect a marginal risk of severe weather associated with this
event. A prefrontal trough associated with the front is expected
to favor maxima of 20-35mm in the Gulf of Honduras region.
Elsewhere in the west Caribbean and south Mexico, expect trace to
light precipitation under 15mm in total. On Thursday, the base of
the potent polar trough reaches the north Caribbean by Thursday
evening, assisting with the southward movement of the cold front
into the central Bahamas, central Cuba, and entering Central
America through the Gulf of Honduras. As this system interacts
with the trades, a weak shear line is expected from east Cuba,
through Jamaica, and into northeast Costa Rica by Thursday
evening. The regions with the heaviest precipitation are expected
in north and central Bahamas, with a slight risk of severe
weather, the Gulf of Honduras region, and from Limon-Costa Rica
into the Colon region of Panama, where expect generalized maxima
ranging from 20-45mm. By Friday, the upper level support of the
frontal boundary begins to propagate into the central Atlantic.
This will weaken the frontal boundary over the west Caribbean and
in Central America, decreasing the potential of moderate to heavy
precipitation over the forecast region. Due to the remnants of
moisture and low level troughing, in the Gulf of Honduras, expect
maxima of 20-35mm. Similar amounts are expected in northeast Costa
Rica. Elsewhere in Mexico, the Caribbean, and Central America,
expect trace to light amounts of precipitation.

In northern South America, the regions of heaviest precipitation
are expected in the western Amazon River Basin, as moisture
continues to remain in the region as the easterly trade winds
advect moist air across the Amazon and into the foothills of the
Andes Mountains. This area is also under the influence of the
periphery of the Bolivian High, as the center meanders over the
Bolivia over the next three days. In the western coasts of
Colombia and Ecuador the presence of the Panamanian Low is
favoring moist onshore flow into the coastal regions. Similarly in
the Guianas, moist onshore flow is favoring moderate precipitation
over the next three days. On Wednesday, from south Colombia into
the Gulf of Guayaquil expect precipitation maxima of 20-45mm. The
western Amazon Basin can expect maxima of 30-60mm, and from
northwest Colombia, into the northwest Amazon, and well as the
eastern Amazon, expect maxima of 20-35mm. On Thursday, expect and
increase in central Colombia due to the presence of a low level
trough over the Caribbean Sea, and the Panamanian trough, that is
favoring moist air into the region, where expect maxima of
30-60mm. The western coasts of Colombia and Ecuador could expect
maxima of 20-45mm. From south Colombia into the Central Amazon,
and the coastal regions of French Guiana and Amapa-Brasil, expect
maxima of 20-35mm. On Friday, enhanced upper level divergence due
to the Bolivian High interacting with a trough axis from a TUTT
over central Brasil that reaches the northern Amazon Basin will
favor heavy precipitation over the west and central Amazon Basin,
with maxima of 35-70mm. French Guiana and Amapa can expect maxima
of 20-45mm as an increase in moist onshore flow reaches the
coastal region on Friday into Saturday. Throughout the forecast
period, localized higher amounts of precipitation are expected as
there is increase upper level divergence, as forecast by the CFS
model, which could be due to a wave similar to an atmospheric
Kelvin Wave, in addition to the interaction of a Rossby Wave that
is expected to propagate over the region over the next three days.

Castellanos...(WPC)