FXCA20 KWBC 071725
PMDCA

Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
124 PM EDT Tue Apr 07 2026

Forecast Bulletin 07 April 2026 at 1630 UTC:

The Bahamas and Caribbean:

A frontal boundary off the east coast of the United States will
promote low-level convergence and low-level cyclonic flow over the
Bahamas and western Cuba, increasing instability and the
development of thunderstorms in the region. Additionally, an
upper-level trough over the eastern United States, which will
propagate east, will increase upper-level divergence over the
Bahamas. A slight risk of severe weather exists for the northern
Bahamas  starting today through Wednesday morning. Accumulations
are expected to reach 20-35mm over The Bahamas, and around 15-25mm
over western Cuba and portions of The Bahamas. Decreasing pressure
north of the Bahamas associated with the frontal boundary will
promote a southerly flow that will draw deep moisture from the
Caribbean into most of the region. Strong low-level winds and
moisture advection will promote thunderstorms and periods of heavy
rainfall over the Dominican Republic today through Wednesday.
Accumulated precipitation will range from 20-45mm, with higher
isolated values expected particularly due to orographic
enhancement. The southeasterly flow will also promote rainfall
over the Lesser Antilles, Puerto Rico. As the frontal boundary
propagates slowly, precipitation is anticipated to continue mainly
over the Bahamas, where the slight risk for severe weather will
continue from Wednesday through Thursday. Over Hispaniola,
conditions at lower levels will continue to be conducive for the
development of precipitation. Over the Lesser Antilles and Puerto
Rico, a more easterly low-level flow, the development of a ridge
at mid- and upper-levels, and a decrease in precipitable water
will result in less precipitation towards the end of the forecast
period.

Mexico and Central America:

Most of the rainfall today through Wednesday is expected to occur
over southern Mexico, Guatemala, Belize, El Salvador, and portions
of Honduras due to low-level moisture convergence, with
accumulation totals around 20mm. Less precipitation is then
expected throughout the rest of the forecast period for most of
Central America, as drier air is advected into the region, while a
mid-level high and zonal upper-level flow bring more stable
conditions. Daily light rainfall, however, is anticipated due to
local effects and diurnal heating.
An increase in precipitation is anticipated for Central Mexico
from Wednesday through Friday, as a shortwave upper-level trough
increases upper-level divergence in the area, enhancing the
development of convective activity. Then, from Thursday through
Friday, precipitation will increase over eastern and northeastern
Mexico, as the low-level southeasterly flow increases and advects
moisture into the region, orographic lift will also promote
rainfall activity over the Sierra Madre Oriental.

Over Costa Rica and Panama, daily rainfall is anticipated due to
the presence of low-level troughing over the Caribbean, which is
enhancing moisture advection and low-level moisture convergence in
the region. Convective activity over Costa Rica will be limited
due to ridging at mid-levels and a more zonal flow prevailing at
upper-levels. Over southern Panama, however, deep convection and
thunderstorms are more likely to occur due to mid- to upper-level
shortwave troughs. Diurnal heating and other local effects will
also promote rainfall in the area throughout the forecast period.

Tropical South America:

Most of the precipitation over tropical South America will be due
to moisture advection, diurnal heating, convectively induced
troughs, and low-level convergence. Heavy precipitation is
expected today through Wednesday over Colombia, particularly over
the Amazon, and the Orinoco region, as a low-level trough
continues to propagate westward, advecting moisture and enhancing
low-level convergence. Orographic lifting over the Andes region is
also likely to occur, promoting rainfall in the region. Total
precipitation will range from 35 - 70mm, with higher isolated
values possible.

Showers and thunderstorms are also expected over the Amazon region
in Peru, due to low-level moisture convergence and the presence of
mid-level shortwave troughs. Upper-level is also anticipated to
support convective activity over the Amazon region in Peru and
Colombia, which will support deep convective activity. From
Wednesday through Friday, precipitation will continue over
Colombia and the western Amazon region, including Peru and Brazil,
as low-level moisture convergence continues and upper-level
divergence along the periphery of the Bolivian High supports the
development of thunderstorms. An increase in rainfall is
anticipated over western Colombia and portions of Ecuador, as deep
moisture increases in the region with the low-level propagating
trough in the area.


Rivera-Torres...(WPC)


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