SOUTH AMERICA MAPS

South of Mexico the global guidance is the forecast. There is no operational high-resolution national model over this continent to fall back on the way the United States has the HRRR or Canada the HRDPS. That makes the choice of global model matter more here than anywhere else on this network, and it is why these two pages open on ECMWF rather than treating the three as interchangeable: it runs at 0.1° where GFS runs at 13 km and GEM at 15, publishes 22 fields here against their seven and eight, and reaches +360 h against their +240 and +120.

Brazil’s own global model is not a fourth option. CPTEC runs BAM, and it is a real operational global model — but it is coarser than all three of these and publishes nothing this site could read, so it is not on the page and this is the only sentence that mentions it. Saying so is better than leaving a reader in São Paulo to wonder whether it was overlooked.

GEM and GFS are still one click away, and comparison is by value. A second opinion is worth more over this continent than anywhere, so all three remain selectable and the pinned readout probes all three at one point at one instant in one unit system. What it will not do is invite you to compare colours: each centre renders on its own palette over its own range, so the legend is redrawn on every switch.

Switching model holds the instant, not the forecast hour. The three run on different cycles, so the same moment is +26 h on one and +20 h on the others. This page keeps the valid time across every switch and says so when the nearest frame it could find is a few minutes off.

The hemisphere explorer offers six framings, one of which is all of South America — nine million square kilometres in a single rectangle, where Amazonia and the Pampas are the same forty pixels. This page offers 41, three tiers deep, and they are the reason it exists separately:

• 14 countries and territories, framed from their own geometry — the extent people live in, extended to the land beside it, so the empty north of Roraima is in the frame and the Galápagos do not drag Ecuador’s box a thousand kilometres out to sea. The islands get a frame of their own instead.
• 23 sub-regions: Amazonia, the Guianas, the Northern Andes, the Altiplano, the Atacama, the Gran Chaco, the Nordeste, the Pampas, the Río de la Plata, Patagonia and Tierra del Fuego — plus Brazil’s five macro-regions and Argentina’s five, because those two are 60% of the continent between them and one national box is not a forecast framing for either. The weather regimes of this continent do not respect borders; half of these are shared by three countries apiece.
• 3 ocean frames — the South Atlantic, the Southeast Pacific and the Drake Passage. A global model earns its keep over water, where there are no observations to fall back on, and every weather problem this continent has arrives off one of the three.

Every framing is a viewport, not a render. ECMWF publishes one worldwide raster; Bolivia is a rectangle on a picture that was already drawn. There is no per-region image tree on any server, and adding a framing costs nothing but a box.

This page is a free camera, which is the right instrument for a reader who has arrived with a question. It is the wrong one for a reader who has the site open all afternoon and is walking one field across twenty framings — because by the third click the camera has drifted, and a change on screen is no longer a change in the weather.

The locked chart viewer is that other instrument, and it is the convention every legacy model site settled on: the map moves only when a region button is pressed, the run is decoded up front, and flipping fields at eight frames a second lands every one in exactly the same rectangle. Locked is not read-only — hovering still reads the value out of the pixel and clicking a city still opens its time series. It is the view that is fixed, not the questions.

Open the locked chart viewer →

Nothing on these pages is hosted here. The frames are fetched straight from forecasteuro.com, forecasteagle.com and forecastcanada.com, which render and publish them. This site runs no model ingest and stores no model imagery — the only file it moves is the METAR feed the country pages read.