Precipitable Water refers to the total amount of water vapor in the atmosphere in a vertical column. It tells us how much moisture is in the air at a given location. Higher values mean there is more moisture available in the air, while lower values indicate drier air.

Precipitable Water is measured by weather balloons at Grand Junction and Denver every day. From this data, we can create a climatology. We expect the precipitable water on any given day to mostly fall within the 10th and 90th percentiles. Also note that the climatology shows that precipitable water is generally lower during the cold months and higher during the warm months.

The current year's data is in black. Days where the precipitable water is very high, compared to the median, indicates there is a lot of moisture in the air that is available for precipitation events.