Region Northwest
The readings under the map are for the whole map, not only the part shown.
GEM · Run 12Z 30 Sep · +0 h · Valid Wed 12Z 30 Sep
One GEM run — issued 12Z 30 Sep — played forward 6 hours at a time, from its analysis to 120 hours out.
Methodology
Nights and days pass as you step this run: that motion is the weather the run forecasts, not the forecast changing. Forecast Evolution is the other film — it holds one moment still and steps the runs, so the only thing that moves there is the model's mind. The colour scale is fitted to the whole run at once, so the same moment reads with more bands here than on the static GEM map; the field is identical. Six-hourly to 120 hours. GEM forecasts out to 240 hours; this film stops at 120. The frames past the one shown load on demand.
This map is drawn from model output we store ourselves, not from anyone's picture of it, and is based on data and products of Environment and Climate Change Canada. The per-city read of the same day — which cities the models are fighting about, and what the discussion makes of it — is on the national page.
Sources and licences
- Environment and Climate Change Canada: GEM, from the MSC Datamart. Data Source: Environment and Climate Change Canada, under its Data Services End-use Licence.
What we change: each field is cropped to the frame these maps share when we download it, and each map then smooths, contours, differences or ranks those numbers as its Methodology says. These are our maps of the providers' numbers, not their products, and none of them has reviewed or endorsed this site.
Coastlines, borders, lakes and place names: Natural Earth, public domain.