Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
122 PM EST Mon Nov 17 2025

Forecast Bulletin 17 November 2025 at 1800 UTC:

The Bahamas and Caribbean:

Dry is present today over the region limiting the amount of
precipitation and the development of deep convection. A series of
induced low-level troughs are expected to affect the Lesser
Antilles, starting today, advecting deep moisture and increasing
instability in the region. A total maximum rainfall accumulation
of 20-35mm is expected from today through Tuesday. More
precipitation is expected from Wednesday through Thursday, as
upper-level divergence increases with an upper level-trough moving
into the area with its base extending over the Caribbean.
Hispaniola is also projected to receive some light rainfall due to
induced low-level troughs, but with precipitable water below 40mm,
high accumulations are not expected from today through Thursday. A
low-level trough southwest of Cuba will enhance low-level moisture
convergence from today through Wednesday. Although most of the
precipitation will remain offshore, Isla de la Juventud and
Matanzas can expect light rainfall with maximum precipitation
around 15-25mm.

Mexico and Central America:

Mostly quiet conditions are expected throughout the forecast
period across Mexico. Some light rainfall, however, can be
expected due to low-level troughs, moisture advection,  diurnal
heating, and local effects including orographic lifting. A mid- to
upper-level trough propagating east into the U.S southwestern
coast is expected to enhance upper-level divergence later today
over Baja California, and on Tuesday, increasing the convective
activity in the area. Total rainfall accumulations around 15-25mm
are expected from today through Tuesday. As the trough propagates
to the east, accumulations are expected to increase over Sinaloa
from Tuesday through Thursday with accumulations reaching 15-25mm.
 An enhancement in low-level convergence is also expected over
Coahuila, increasing rainfall in that area from Wednesday to
Thursday morning.

Over Central America, an upper-level high is expected to prevail
over the forecast period favoring a more stable environment. From
today through Wednesday, a low-level trough will bring light
precipitation over western Guatemala and El Salvador, with maximum
accumulations around 20mm. From Wednesday through Thursday
moisture advection should bring some rainfall to Nicaragua, where
totals are expected to reach 35mm.

Precipitation is expected each day over Costa Rica and Panama with
the presence of the monsoon trough favoring low-level moisture
convergence. Dry air is expected to reach the area, likely
limiting high totals of rainfall over Costa Rica, but low-level
convergence should continue enhancing precipitation over Panama
from Tuesday through Thursday.

Tropical South America:

Low-level westerly flow is expected to bring moisture from the
Pacific onshore over western Colombia each day of the forecast
period. Precipitation is expected to increase from Wednesday
through Thursday as the low-level flow becomes more favorable for
onshore moisture advection.

Over the rest of tropical South America, most of the precipitation
will be associated with low-level convective induced troughs,
low-level moisture convergence, moisture advection, diurnal
heating, and orographic lifting. A high, currently over eastern
South America, is expected to move westward and weaken by
Wednesday. An enhancement in upper-level divergence along the
periphery of the high is expected, particularly over Colombia and
portions of Ecuador where most of the convective activity is
expected to happen from today through Wednesday. 

Moisture advection is expected from today through Tuesday, causing
some light rainfall over Guyana, Suriname and French Guiana.
Precipitation is then expected to increase from Tuesday through
Thursday over eastern Venezuela, Trinidad and Tobago and Guyana as
moisture continues to be advected in the region and low-level
convergence increases with an induced low-level trough increasing
instability in the area. Deep convection and thunderstorms are
expected in the region as upper-level divergence increases in the
Caribbean


Positions of Tropical/Easterly Waves Initialized at 12 UTC
TYP SOF  INIT  18/00  18/12  19/00  19/12  20/00  20/12  21/00
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For the latest available charts please visit:
https://www.wpc.ncep.noaa.gov/international/crb_day1-3.shtml

Rivera-Torres...(WPC)