Precipitation from Fog Moisture in the Green Mountains of Vermont

Fog and low—lying clouds occur frequently on the higher slopes in the Green Mountains of Vermont. To determine the amount of precipitation contributed from cloud moisture, rain gauges were equipped with screen coils to intercept and collect cloud droplets. Screened gauges were paired with unscreened gauges and set out in forest openings along a mountain slope at 1,800, 2,800, and 3,600 ft. After 8 weeks the screened rain gauge at 1,800 ft collected slightly less water than the unscreened gauge. But at 3,600 ft, where clouds and fog are frequent, the screened gauge collected 66.8% more water than the unscreened gauge.