A big storm is on the way. Relative humidity begins a slow rise as cloud cover moves in. Suddenly the wind picks up speed.
Gusts peak at over fifty miles an hour.
The relative humidity increases sharply as the air temperature drops. Heavy rain begins. The downpour lasts an hour, during which almost two inches of rain falls. The wind direction shifts from southwest to northwest as the front passes. Front passage is confirmed as the barometric pressure begins a rapid rise.