South America Forecast Discussion - International Desks
NWS Weather Prediction Center College Park MD
315 PM EST Wed Feb 11 2026

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

Forecast Bulletin 11 February 2026 at 1930 UTC:

Heavy rainfall and convective activity are expected today through
Thursday over portions of Central-West and portions of Northern
Brazil, including Mato Grosso and Tocantins. The advection of deep
moisture, low-level wind convergence, in addition to the presence
of upper-level divergence with the presence of an upper-level
trough over northeastern Brazil and an upper-level high over
Bolivia will support the development of thunderstorms in the area.
Accumulations are expected to range from 35-70mm, with isolated
higher values. Low-level moisture convergence and upper-level
diffluence will continue to support convective activity over the
Amazon region in Brazil and portions of Mato Grosso. Additional
30-60mm are expected from Thursday through Friday. As dry air from
the Atlantic is advected into Brazil, a drying trend is
anticipated towards the end of the forecast period. Most of the
precipitation is expected over the Amazon region in Brazil, over
Peru, and portions of Bolivia due to low-level moisture
convergence and enhanced upper-level divergence. Totals around
40-80mm can be expected.

Low-level moisture convergence and the presence of a shortwave
mid-level trough are expected to enhance precipitation along the
Selva Alta in Peru, today into Thursday, particularly during the
evening. Totals are anticipated to be around 20-45mm. Mid-level
troughing and low-level convergence will also bring some
precipitation over the Western Amazon region in Peru, including
portions of Brazil.

A low-level trough is expected to enhance moisture advection over
portions of the Guianas and the Amazon Delta region in Brazil,
increasing precipitation today through Thursday. A total of
20-45mm is forecasted, but higher isolated totals are likely. A
drier pattern is expected after Thursday morning, with limited
precipitable water availability in the region.

A frontal boundary that extends into Uruguay will bring heavy
precipitation, and severe weather to Uruguay, Argentina and
southern Brazil from today through Friday. The presence of
mid-level shortwave troughs and upper-level divergence associated
with a jet is expected to provide further support for the
development of convective activity in the region. Over portions of
Pampas, Mesopotamia and Uruguay thunderstorms will start late on
Wednesday night and are expected to continue until Thursday
morning. Total accumulations will likely reach 40-80mm over
Argentina and Uruguay. As the frontal boundary progresses
precipitation is expected to increase in southern Brazil from
Thursday through Friday. Mid-level shortwave troughs will enhance
instability in the area, and periods of heavy precipitation are
expected. Precipitation will continue over Argentina and Uruguay
with the presence of a low-level trough and moisture being
advected into the region. From Friday through Saturday a low-level
trough and high precipitable water in the region will continue to
support periods of moderate to heavy rainfall over southern
Brazil. High precipitable water and mid-level shortwave troughs
will also support precipitation over Paraguay and northern
Argentina.





Rivera-Torres...(WPC)