South America Forecast Discussion - International Desks
NWS Weather Prediction Center College Park MD
309 PM EST Thu Feb 12 2026

GFS data at ftpprd.ncep.noaa.gov/data/nccf/com/gfs/prod/

Forecast Bulletin 12 February 2026 at 1930 UTC:


The presence of a low-level trough over Ecuador, and the advection
of deep moisture into Ecuador will enhance showers activity today
through Friday. Additional support for the development of
thunderstorms is likely with a weakening mid-level shortwave
through increasing instability.

A short wave upper-level trough is anticipated to increase
upper-level divergence today over Peru, which in combination with
mid-level troughing will bring precipitation, particularly along
Selva Alta where low-level moisture convergence is expected. Snow
is also likely over mountains from today through Friday.

In Brazil, showers and convective activity is anticipated to occur
over the Central and Amazon region today through Friday. The main
drivers of this precipitation will be upper-level divergence, and
low-level moisture advection. Less precipitation is anticipated
for the northeast, with drier air dominating over the region.

An increase in precipitation is expected from Friday through
Sunday over the Western Amazon Basin, which includes portions of
Ecuador, Peru and Brazil, with the development of the
Near-Equatorial Trough (NET) on Friday. The NET is anticipated to
increase convergence at low-levels, which combined with high
values of PWAT over the Amazon region of the continent will result
in heavy rainfall and support the development of thunderstorms.
From Friday through Saturday, totals are expected to range between
40-80mm. Low-level convergence will continue over the region from
Saturday through Sunday, and an additional 35-70mm of rainfall is
likely in the same region.

Heavy precipitation is anticipated for southern Brazil starting
today through Friday, with frontal boundaries in the Atlantic
enhancing low-level moisture convergence in the region and the
development of low-level troughs over land. In addition,
upper-level divergence will support convective activity in the
region.

A frontal boundary is forecasted to enhance low-level moisture
convergence over Uruguay, and Mesopotamia  in Argentina today
through Friday. Diffluence at mid- and upper-levels will further
enhance instability in the region, increasing the likelihood of
thunderstorms and severe weather until Friday morning. From today
through Friday totals are forecasted to exceed 50mm in the region.
Heavy precipitation due to the frontal boundary and enhanced
low-level moisture convergence will continue over southern Brazil
and portions of Paraguay from Friday through Saturday, with totals
anticipated to reach 40-80mm. As the frontal boundary progresses,
an enhancement of precipitation is expected for the Santa Catarina
and Parana region in Brazil.





Rivera-Torres...(WPC)