Absolute PWAT
Deepest column 65 mm near Leesburg, Florida
Deepest column 63 mm, 110 km E of La Paz, Mexico
Deepest column 64 mm, 105 km WSW of Los Mochis, Mexico
Deepest column 63 mm, 115 km ESE of Loreto, Mexico
Deepest column 64 mm near Huatabampo, Mexico
Deepest column 64 mm near Guaymas, Mexico
Deepest column 63 mm, 105 km W of Puerto Vallarta, Mexico
Deepest column 63 mm near Biloxi, Mississippi
Deepest column 64 mm, 35 km S of Santiago Ixcuintla, Mexico
Deepest column 63 mm near Pánuco, Mexico
Deepest column 65 mm at 20.0N 123.75W
Deepest column 65 mm at 20.75N 124.25W
Deepest column 66 mm at 20.0N 126.0W
Deepest column 66 mm at 20.0N 127.25W
Deepest column 66 mm at 20.0N 131.0W
Deepest column 67 mm at 20.0N 131.0W
Deepest column 67 mm at 20.0N 128.75W
Deepest column 68 mm at 20.0N 130.0W
Deepest column 66 mm near Escuinapa, Mexico
Deepest column 66 mm at 20.0N 133.25W
Deepest column 66 mm at 20.0N 135.0W
One ECMWF run, issued 00Z 15 Sep — played forward 6 hours at a time, from the analysis to 120 hours out.
Methodology
PWAT — precipitable water — is how much water vapour the air overhead holds, as the depth of water it would make if it all fell at once.
Six-hourly to 120 hours. ECMWF's 00Z run forecasts out to 360 hours; this film stops at 120.
The colours are a depth scale, the same everywhere: the cream band is a depth, not a normal. The same column is deep for Salt Lake City and shallow for Miami, so this map cannot say whether the air is unusual — the Relative to normal chart ranks each place against its own record, and that is the one to read for that.
GFS files this field as PWAT and ECMWF as total column water vapour, the same quantity. 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.
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.