Region Lower 48
The readings under the map are for the whole map, not only the part shown.
Surface pressure (hPa) and 6-hour averaged precip rate (in/h)
GEM · Run 12Z 1 Oct · +6 h · Valid Thu 18Z 1 Oct
Surface pressure (hPa) and 6-hour averaged precip rate (in/h)
Heaviest 6-hour mean 0.491 in/h, near 39.0N 99.9W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.488 in/h, near 37.8N 100.05W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 1.269 in/h, near 26.25N 99.15W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 1.174 in/h, near 25.2N 99.6W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.48 in/h, near 28.35N 97.95W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.587 in/h, near 32.1N 82.05W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.712 in/h, near 22.35N 99.3W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.405 in/h, near 21.15N 98.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.501 in/h, near 29.25N 94.2W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.692 in/h, near 20.25N 112.95W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.677 in/h, near 30.75N 82.05W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.659 in/h, near 25.65N 98.85W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.6 in/h, near 30.3N 90.9W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.505 in/h, near 20.1N 96.15W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.774 in/h, near 25.05N 99.15W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.81 in/h, near 21.3N 97.65W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.732 in/h, near 21.0N 96.6W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.504 in/h, near 29.85N 81.6W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.299 in/h, near 28.65N 81.0W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.652 in/h, near 20.55N 97.05W · unshaded ground is where the model has under 0.01 in/h falling
One GEM run — issued 12Z 1 Oct — played forward 6 hours at a time, from 6 hours out to 120 hours out.
Methodology
Step forward and the pressure pattern moves, and the precipitation under it moves with it: that motion is the weather this run forecasts, not the forecast changing — Forecast Evolution is the film for that. Same chart grammar as the surface analysis: the same reduction, the same 4 hPa interval, the same frame; only the forecast hour varies. 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. GEM publishes no precipitation rate, so the shading here is the 6-hour mean rate — the run's total precipitation at each frame less the total 6 hours before, over 6 — on the same scale as the instant the other models shade with. A mean over 6 hours is smoother and weaker than an instant, so its heavy bands light less often on the same weather; and because no 6-hour bucket ends at the analysis, this film opens at +6 h rather than showing one frame with no rain under it.
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. Every model's full forecast for any of these cities, or anywhere else, is in the beta: request an invite; it's free during the beta.
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.