Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
123 PM EST Mon Mar 02 2026

Forecast Bulletin 02 March 2026 at 1830 UTC:

For the next three days, rainfall processes will be driven by the
low levels across Central America, tropical South America, and the
Caribbean Islands.

In Central America, expect the Caribbean low level jet (CLLJ) to
be present and assisting in the enhancement of low level cyclonic
circulation across the Caribbean coasts of eastern Honduras,
Nicaragua, and northern Costa Rica for the entire forecast period.
Expect the arrival of a low level trough overnight Monday into
Tuesday that will lead to a subtle increase in moisture
convergence. These conditions will favor a total precipitation
maxima of 15 - 20mm through Tuesday morning across the Nicaraguan
coast. By Tuesday evening, a long-fetch moisture plume will begin
to converge into Nicaragua and northern Costa Rica, where
precipitable water values will be reaching 38mm. Anticipate higher
accumulations compared to the day prior, where the maxima will
approach 15 - 25mm from Tuesday morning through Wednesday morning.
On Wednesday afternoon, the axis of another low level trough will
be moving into Nicaragua and eastern Honduras, favoring an
increase in low level cyclonic circulation and moisture
convergence. From Wednesday morning through Thursday morning,
expect the most intense precipitation accumulations for the
three-day period, with maxima ranging from 20 - 35mm.

Across the Caribbean Islands and Bahamas, there will be a series
of low level troughs that will increase moisture convergence
across Cuba, Jamaica, Hispaniola, and Puerto Rico for the next
three days. On Monday afternoon, a low level trough that will be
accompanied by a subtle increase in precipitable water will begin
moving into southeast Cuba and Jamaica. A total precipitation
maxima of up to 15mm is possible through Tuesday morning with the
passage of this trough. Meanwhile in Hispaniola, there is
currently a low level trough that is propagating into the Mona
Passage and is anticipated to move into Hispaniola on Monday
afternoon. Expect the diurnal cycle to reinforce the sustenance of
precipitation across eastern Hispaniola. The trough will continue
moving over the island through the night. This trough will support
total precipitation maxima of 15mm across eastern Dominican
Republic through Tuesday morning. The trough and its affiliated
moisture plume will begin moving over southeast Cuba and Jamaica
during the day on Tuesday, bringing with an increase in moisture
convergence. These conditions will favor total precipitation
maxima of 10mm from Tuesday morning through Wednesday morning in
Jamaica. A third low level trough will develop over the Virgin
Islands and its axis and affiliated moisture plume will quickly
move over Puerto Rico during the day on Wednesday and arrive into
the Dominican Republic by Wednesday afternoon. These conditions
will favor a total precipitation maxima of 10mm and 15 - 20mm
across Puerto Rico and the Dominican Republic respectively from
Wednesday morning through Thursday morning. The moisture plume
will arrive in southwest Cuba by early Thursday morning. The fast
propagation speed of this third low level trough is due to the
intensifying Caribbean low level jet to the south and the
development of a secondary low level jet north of the Greater
Antilles islands.

In Tropical South America, a low level trough is currently located
off the Pacific coast of Ecuador and Colombia and its structure
will start to become disorganized starting Thursday. During this
period, precipitable water values will be reaching 50mm. With
respect to precipitation, the area with the greatest impact will
be across Ecuador, where the low level wind flow will be from the
west and southwest for Monday and Tuesday. A daily total
precipitation maxima of 20 -45mm is likely during this period. The
low level wind pattern will also favor orographic enhancement. For
Wednesday, there is model disagreement on the low level wind
direction, but regardless, there will be ample moisture in the
region. Moisture convergence will thus be enhanced by local
effects. Total precipitation maxima from Wednesday morning through
Thursday morning is expected to range from 20 - 35mm, though
locally higher accumulations are likely. Meanwhile along the
Colombian coast, local effects and the diurnal cycle will drive
precipitation processes through the next three days and will favor
daily total precipitation maxima of at least 35mm.

East of the Andes, the nocturnal low level jet will be
intensifying and will drive a drying trend across the northern
half of the tropical region of South America. Thus, the regions
with the greatest chances for precipitation will be across the
central and western Amazon Basin, where the moisture content will
also be highest in comparison. Another region that will see
significant precipitation accumulations is the Amazon Delta. The
precipitation processes will be influenced by the presence of the
Intertropical Convergence Zone (ITCZ), especially for Tuesday and
Wednesday when the ITCZ will be shifting northward. Expect
moderate accumulations for this period.

Across the rest of the basin, expect seasonal conditions. Daily
diurnal convection and showers are still anticipated across
Mexico, Central America, the Caribbean, the Bahamas, and tropical
South America for the next three days.

Tinoco-Morales...(WPC)