Dear Tom,
How can it rain for four or five days as it has at times this year? At some point doesn't the atmosphere in any local geographical area become depleted of moisture until evaporation can replace it?
Rob Neufeld
Dear Rob,
The total amount of water evaporated in a column of air above a location is known as precipitable water. It is the amount of water that would fall to the surface if all the water vapor in the atmosphere above that spot condensed and fell as rain.
A precipitable water value of 2.00 inches is exceptionally high and rarely occurs in the Midwest. Nevertheless, rain totals far greater than 2.00 inches occur quite often. This implies that moisture, carried by wind, moves to the location at which rain is falling and continuously re-supplies the rain-producing mechanism (such as a thunderstorm). And that is exactly what occurs in heavy rain events.
How can it rain for four or five days as it has at times this year? At some point doesn't the atmosphere in any local geographical area become depleted of moisture until evaporation can replace it?
Rob Neufeld
Dear Rob,
The total amount of water evaporated in a column of air above a location is known as precipitable water. It is the amount of water that would fall to the surface if all the water vapor in the atmosphere above that spot condensed and fell as rain.
A precipitable water value of 2.00 inches is exceptionally high and rarely occurs in the Midwest. Nevertheless, rain totals far greater than 2.00 inches occur quite often. This implies that moisture, carried by wind, moves to the location at which rain is falling and continuously re-supplies the rain-producing mechanism (such as a thunderstorm). And that is exactly what occurs in heavy rain events.
