Absolute PWAT
Deepest column 2.57 in at 20.0N 134.75W
Deepest column 2.76 in, 20 mi WSW of Tecuala, Mexico
Deepest column 2.59 in at 20.0N 135.0W
Deepest column 2.61 in at 37.5N 66.75W
Deepest column 2.49 in at 36.75N 65.75W
Deepest column 2.51 in, 40 mi NW of Puerto Vallarta, Mexico
Deepest column 2.45 in, 70 mi SW of Puerto Vallarta, Mexico
Deepest column 2.38 in at 25.0N 85.25W
Deepest column 2.57 in, 35 mi ENE of Nueva Gerona, Cuba
Deepest column 2.51 in near Villa Unión, Mexico
Deepest column 2.50 in, 30 mi WSW of Escuinapa, Mexico
Deepest column 2.42 in, 130 mi SE of New Orleans, Louisiana
Deepest column 2.57 in, 75 mi S of Houma, Louisiana
Deepest column 2.52 in at 20.0N 121.5W
Deepest column 2.56 in at 20.25N 123.0W
Deepest column 2.74 in at 20.0N 123.75W
Deepest column 2.74 in at 20.0N 124.75W
Deepest column 2.79 in at 20.5N 126.25W
Deepest column 2.69 in at 20.25N 128.5W
Deepest column 2.70 in at 20.0N 126.0W
Deepest column 2.76 in at 20.75N 127.5W
One GFS run, issued 00Z 14 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.