Absolute PWAT
Deepest column 67 mm near Kissimmee, Florida
Deepest column 64 mm, 50 km NE of La Paz, Mexico
Deepest column 62 mm, 100 km NNE of La Paz, Mexico
Deepest column 63 mm, 110 km E of Loreto, Mexico
Deepest column 64 mm, 70 km S of Naples, Florida
Deepest column 64 mm near Escuinapa, Mexico
Deepest column 64 mm, 100 km SW of Hermosillo, Mexico
Deepest column 64 mm at 20.0N 120.0W
Deepest column 65 mm at 20.0N 119.5W
Deepest column 64 mm at 20.25N 120.5W
Deepest column 64 mm, 105 km W of Puerto Vallarta, Mexico
Deepest column 65 mm at 20.0N 123.25W
Deepest column 65 mm at 20.25N 128.25W
Deepest column 66 mm at 20.5N 128.75W
Deepest column 66 mm at 20.0N 125.25W
Deepest column 68 mm at 20.0N 127.0W
Deepest column 68 mm at 20.75N 128.25W
Deepest column 68 mm at 21.0N 132.25W
Deepest column 68 mm, 130 km W of Puerto Vallarta, Mexico
Deepest column 67 mm at 20.25N 132.5W
Deepest column 68 mm at 21.25N 135.0W
One GFS 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. GFS forecasts out to 384 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 NOAA. 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
- NOAA: GFS, from NOAA's NOMADS server. US government data, not subject to copyright (NOAA/NWS terms of 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.