Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
235 PM EST Mon Nov 09 2026

Forecast Bulletin 09 November 2026 at 1930 UTC:

Northern South America
The Bolivian High remains active over much of the central portion
of South America, reaching into portions of the Amazon Basin and
northwest South America, where it is interacting with a ridge over
the Caribbean and Central America. The area where these systems
meet is favoring the development of shortwave troughs that assist
with the ventilation of the convection in the region. To the west,
the East Pacific warming is fueling the presence of the southern
branch of the ITCZ, entering into west Ecuador and southwest
Colombia. This low level convergence will favor maxima of 20-45mm
with a potential for locally higher totals. To the north and east,
moisture advection and low level troughing and convergence will
persist with the upper level support of the Bolivian High
periphery.  On Tuesday, the conditions over the eastern Pacific
will persist and favor similar daily total precipitation in west
Ecuador and west Colombia. The moisture over the Amazon Basin
enters into Colombia and increases in the north as a moist plume
associated with the Central Atlantic enters into north Venezuela
and Colombia, where the mountain range will enhance lift and favor
precipitation on Tuesday. Dry air moisture advection remains
present over the southern Guianas and eastern Para and
Amapa-Brasil. By Wednesday, a similar pattern will remain in the
northern portion of the continent, with the addition of increased
moisture in the northern Guianas. Expect light to moderate showers
scattered in the region on Wednesday.

Central America
The remnants of a low level circulation propagate west into the
Pacific while the mid and upper level troughing enters the Gulf of
Fonseca early Monday and propagates northward, as it converges
with the moisture advected by the easterly trade winds from the
Caribbean Sea. That will fuel the deep convection that generates
on Monday over Honduras and the west Caribbean. With the low level
winds entering primarily from the east into southern Belize, north
Guatemala, and north Honduras, orographic lift will favor
precipitation on Monday, with a chance that locally heavier
precipitation is present. On Tuesday, the mid to upper level ridge
begins to weaken as it reorganizes over the Pacific Ocean, and
another ridge strengthens in the Central Atlantic. A potential for
mid-level troughing in the west Caribbean will ventilate the
convection in Honduras and Nicaragua, favoring moderate
precipitation totals on Tuesday. By Wednesday, the moist and
unstable conditions will persist in the eastern costs of Honduras
and Nicaragua as the presence of the Caribbean Low Level Jet
strengthens.

Caribbean and the Bahamas
The northern sector of the region is seeing the effects of weak
frontal boundaries over the Bahamas and prefrontal troughs that
enter the Greater Antilles on Tuesday. In the mid to upper levels,
the ridge is favoring the weakening of these frontal boundaries,
while favoring the presence of the Caribbean LLJ in the low
levels, advecting dry air over the central and eastern portions of
the region. By Tuesday, the upper level ridge weakens, while a
strong mid to upper level ridge positions itself in the central
Atlantic. This ridge will be the driver for much of the trade wind
inversion caps over the eastern Caribbean on Tuesday and into
Wednesday. Much of the precipitation will be expected in the
southern Bahamas, Turks and Caicos, and the Greater Antilles with
the presence of moisture and low level troughing. Daily light to
locally moderate precipitation totals are expected.

Mexico
The majority of the country is expected to see dry conditions with
light precipitation, primarily to the south and east. In the
northeast region, an area of low level troughing is bringing
moisture into Tamaulipas and northern Veracruz, with maxima of
20-35mm on Monday. Elsewhere, expect general maxima of 15-20mm.
Similar conditions are expected on Tuesday, with the moisture in
the northeast sector decreasing slightly as a low-level ridge
develops to the east of Mexico. By Friday, the available moisture
is advected into the Bay of Campeche and central Veracruz as a new
frontal boundary enters the southern United States.

Castellanos...(WPC)