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)
ECMWF AIFS · Run 18Z 30 Sep · +6 h · Valid Thu 00Z 1 Oct
Surface pressure (hPa) and 6-hour averaged precip rate (in/h)
Heaviest 6-hour mean 0.266 in/h, near 40.0N 99.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.334 in/h, near 41.0N 97.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.221 in/h, near 20.0N 110.75W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.217 in/h, near 20.0N 108.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.204 in/h, near 20.0N 108.75W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.176 in/h, near 20.0N 109.0W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.172 in/h, near 20.0N 109.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.171 in/h, near 20.0N 109.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.191 in/h, near 20.0N 110.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.208 in/h, near 20.0N 110.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.233 in/h, near 20.0N 111.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.274 in/h, near 20.0N 111.75W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.237 in/h, near 20.0N 112.25W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.228 in/h, near 20.0N 112.75W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.217 in/h, near 20.0N 113.0W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.222 in/h, near 20.0N 113.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.23 in/h, near 20.0N 114.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.242 in/h, near 20.0N 114.75W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.221 in/h, near 20.0N 115.5W · unshaded ground is where the model has under 0.01 in/h falling
Heaviest 6-hour mean 0.203 in/h, near 20.0N 116.25W · unshaded ground is where the model has under 0.01 in/h falling
One ECMWF AIFS run — issued 18Z 30 Sep — 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 2 hPa interval, the same frame; only the forecast hour varies. Six-hourly to 120 hours. ECMWF AIFS forecasts out to 360 hours; this film stops at 120. The frames past the one shown load on demand. ECMWF AIFS 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 the European Centre for Medium-Range Weather Forecasts (ECMWF). 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
- ECMWF: AIFS Single, from ECMWF's open data. This service is based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF). Source: www.ecmwf.int. This ECMWF data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0). ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.
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.