Absolute PWAT
Deepest column 2.56 in at 20.0N 131.25W
Deepest column 2.49 in near Escuinapa, Mexico
Deepest column 2.64 in at 20.0N 134.25W
Deepest column 2.75 in at 20.0N 134.75W
Deepest column 2.56 in at 20.0N 135.0W
Deepest column 2.48 in, 40 mi SSW of Los Mochis, Mexico
Deepest column 2.42 in near Guamúchil, Mexico
Deepest column 2.42 in, 25 mi W of Compostela, Mexico
Deepest column 2.44 in, 30 mi SW of Huatabampo, Mexico
Deepest column 2.43 in, 25 mi ESE of Guaymas, Mexico
Deepest column 2.51 in near Tuxpan, Mexico
Deepest column 2.50 in, 25 mi W of Compostela, Mexico
Deepest column 2.55 in, 30 mi W of Tuxpan, Mexico
Deepest column 2.49 in, 100 mi WSW of Puerto Vallarta, Mexico
Deepest column 2.50 in at 20.0N 124.0W
Deepest column 2.59 in at 20.0N 126.0W
Deepest column 2.64 in at 20.25N 126.25W
Deepest column 2.66 in at 20.25N 129.5W
Deepest column 2.67 in at 21.25N 129.5W
Deepest column 2.66 in at 20.75N 131.5W
Deepest column 2.65 in at 21.5N 129.25W
One ECMWF run, issued 12Z 13 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.
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. Raw model output.
Every map on this page is drawn from model output we store ourselves, not from anyone's picture of it. 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.