Electronics World Cover,TOC,and list of posted Popular Electronics articles QST Radio & TV News Radio-Craft Radio-Electronics Short Wave Craft Wireless World About RF Cafe RF Cafe Homepage RF Cafe in Morse Code Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs Twitter LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes AN/MPN-14 Radar 5CCG Notable Quotes App Notes Calculators Education Magazines Software,T-Shirts,Coffee Mugs Articles - submitted by RF Cafe visitors Simulators Technical Writings RF Cafe Archives Test Notes RF Cascade Workbook RF Stencils for Visio Shapes for Word Thank you for visiting RF Cafe!

Rain (Rainfall) Facts

RF Cafe - Weather Radar MapWhen you listen to the weather report and hear that there is a chance for light rain or that it is currently drizzling, there is actually a scientific method for defining the terminology. Now, if the person making the report is just a local broadcaster looking out the window to render an opinion, then the definitions listed below are not guaranteed to apply, but if the forecast is coming from a certified weatherman, then there is a pretty good chance that the number of drops per second per square foot really does fall within the ranges below.

Weather radar displays present rainfall intensity legends that report units of dBZ, which are decibels relative to "Z," with "Z" being the reflectivity factor.

  Number of Drops
(per ft2 per sec)
Diameter of Drops
(in. per hr.)
Cloudburst 113 2.85 4.0 60
Excessive Rain 76 2.4 1.6 50
Heavy Rain 46 2.05 0.6 40
Moderate Rain 46 1.6 0.15 30
Light Rain 26 1.24 0.04  
Drizzle 14 0.96 0.01 20
Mist 2,510 0.1 0.002 10
Fog 6,264,000 0.01 0.0005  

One interesting tidbit not included in the table above is that technical difference between rain and a shower. Rain refers to precipitation from stratiform clouds like stratus and altostratus, and tend to occur over a large area for a long time. Showers originate from cumulus and cumulonimbus clouds and cover a relatively small area for a short time.

So, when somebody remarks that, "we have had a ton of rain," just how much rain is that?
   Answer: 0.01 inches of rain over an acre of land equals 62,726 cubic inches, or 1.1 tons.

How fast does rain fall?
   Answer: Around 30 km per hour (18.6 mph), depending on the updraft.

Try Using SEARCH to Find What You Need.  >10,000 Pages Indexed on RF Cafe !

Copyright 1996 - 2016
Webmaster:  Kirt Blattenberger, BSEE - KB3UON
Family Websites:  Airplanes and Rockets | Equine Kingdom

All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.