The Spread Maps Request an invite

Run total + precip rate + MSLP

All maps

ECMWF · Run 12Z 15 Oct · +0 h · Valid Thu 12Z 15 Oct

Region Northeast

United States

Lower 48 Northwest Southwest Northern Plains Southern Plains Midwest Northeast Mid-Atlantic Southeast

Europe

Europe

The readings under the map are for the whole map, not only the part shown.

100810101012101210141014101410141014101410161016101610161016101610161016101610181018101810181018101810181018101810201020102010201020102010201020102210221022102210221022102410241024102410241024102610261026102810281030103010321032103410361038 L1013L1007H1040L1014H1028

ECMWF · Run 12Z 15 Oct · +0 h · Valid Thu 12Z 15 Oct

Nothing on the map has reached 0.01 in yet · heaviest rate 0.753 in/h at Thu 12Z

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

Methodology

Two of this site's films laid one over the other. Underneath is the Run total: everything this run puts down from its start to each frame, on Tropical Tidbits' scale. On top is the pressure Time lapse: the precipitation falling at that frame's time, on the radar scale, and the sea-level pressure at that time in 2 hPa isobars. So the rate moves on as the film plays and leaves its total behind it. The first frame is the analysis, where the run has put nothing down yet.

The total is a window and the rate and the pressure are instants, all read at the frame's valid time: the total runs from the start of the run to that time. Liquid-equivalent: snow counts as the water it melts to. GFS and ECMWF only, the two models here that publish an instantaneous rate.

Six-hourly to 360 hours. ECMWF's 00Z and 12Z runs forecast out to 360 hours, its 06Z and 18Z runs to 144. The frames past the one shown load on demand. Uncorrected model output.

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: IFS, 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.