Drop Size

[Ethan Lang]

One thing that has always puzzled me as a chaser is how on some days the rain drops in the storms are huge and other days the drops are not as large. Does this have to do with precipitable water, dew points, etc. Can someone help me on this.

 

[Jeff House]

All of the above. Cloud dynamics plays a big role too. Much depends on layers of clouds, location of drop production, and accretion from there. We just had the ol' tropical fine but heavy mist in Chattanooga on Sunday.

 

[Jeff Duda]

You're basically sampling different parts of in-storm drop size distributions. DSDs vary from one day to another, as well, but also tremendously from one part of a storm to another.

Does it have to do with precipitable water, dew points etc? Yeah, about as much as it depends on where you are in the storm and how well organized the storm is.

 

[Paul Knightley]

The height from which drops fall also has an effect - for example, drizzle falls from very low clouds - if it had to fall further it would likely evaporate. Large drops can indicate a high cloud base.

However, updraught strength is another player - generally, bigger drops indicate stronger updraughts.