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MSLP + precip rate

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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)

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ECMWF AIFS · Run 12Z 15 Oct · +6 h · Valid Thu 18Z 15 Oct

ECMWF AIFS · Run 12Z 15 Oct · +6 h · Valid Thu 18Z 15 Oct

Surface pressure (hPa) and 6-hour averaged precip rate (in/h)

Heaviest 6-hour mean 0.135 in/h, near 34.5N 98.25W · unshaded ground is where the model has under 0.01 in/h falling

One ECMWF AIFS run — issued 12Z 15 Oct — played forward 6 hours at a time, from 6 hours out to 360 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 360 hours. ECMWF AIFS forecasts out to 360 hours. 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. 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
  • 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.