Monday, May 17, 2010

Rainy Next 48 Hours

The grass is much greener now that we've had a few weeks of above normal rainfall. The trees are almost at  their peak and the late spring flowers are about ready to bloom.  Although the weekend was more or less dry and comfortable, the next southern system is now over the area and promises to produce yet another round of rainy weather over the next 36 hours.

Where is all of this moisture coming from?

To answer this, we have to go to the tropics and a term called:  PRECIPITABLE WATER

If you were to squeeze out ALL of the water vapor in the clouds in the form of rain, that is called PRECIPITABLE WATER.  The higher the PW, the more moisture in the atmosphere.  Higher moisture values are represented with warmer colors on the image here from the National Oceanic and Atmospheric Administration.


The band of red and yellow shows the higher pool of moisture over the tropics.  Every once in a while, a tongue of moisture will stream north through the central US.  Often in the spring, this tongue of tropical moisture will make it all of the way into northern Ohio. Its this moisture source that is responsible for the frequent rains over the last two weeks.  Expect more this week.

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