WeatherQuesting
with April Holladay
to solve weather mysteries, your wonders.

Also, WonderQuest with April Holladay
 

Home   Top 10    Newsletter    Fast answers    Site Map

Google
 
Web www.WeatherQuesting.com


RSS Add to Google

Answers about:  

_   Lightning
_ Clouds

Top 10 questions  

1

 Cause of  lightning

2

 Where lightning hits

3

 Hurricane spin

4

 How hot is lightning

5

 Jupiter's surface

6

 How rainbows form

7

 Ball lightning

8

 Hurricane energy

9

 Lightning hits a tornado
10  Orange night skies

Current Column:  A saintly light

st elmo's fire

Why would a lightning-struck tree glow after being hit? It is not on fire and does not give off heat, but glows. 

It was a dark and stormy night.  Chris emails he was walking in the woods  "a little after a thunderstorm" when he noticed the tree.  The tree, shattered by an earlier lightning stroke, stabbed the night like a broken pike.  An eerie glow extended ... Click to continue

Wind-chill experiment

Here's how you can test whether water will freeze with an ambient temperature of 35° F (2° C) and a wind chill factor of 25° F (-4° C).  First, you need a fan since it takes a 15 mph (24 kph) wind to produce a wind chill factor of 25° F if the air temperature is 35° F.

  1. Empty the refrigerator (ideally) or put the food on one shelf to allow air flow.  Take out any glass shelves or shelves that block air flow.
  2. Set the refrigerator to 35°; put a check thermometer in.
  3. Set a pan of water on the middle rack.
  4. Place a small battery-powered fan on the top shelf pointed at the pan of water.  A link for a $14 battery-operated fan is given below.
  5. Estimate the air speed from the fan onto the water by feel with your hand.  Close the refrigerator door as much as possible on your arm while estimating the air speed.  You probably can guess that the air speed is, say, somewhere between 5 mph and 20 mph with some confidence.
  6. Calculate or look up the wind chill factor associated with your air speed estimates and refrigerator temperature.  A link for a lookup table is given below.
  7. Stick a thermometer in the pan of water.
  8. Check the temperature of the water until it reaches about 35°. 
  9. Leave the experiment going overnight to see if the water ever freezes. 

Good luck!

NOAA: National Weather Service wind chill chart

Safety Central: $20-battery operated fan

(Answered June 27, 2003; updated Oct. 3, 2007)

Click for printer version.

Site Map

Archive Features Info
Question Archive WeatherQuesting's Search
    Ask a question About April

 

  Lightning Rain & snow   Top 10 questions Add RSS feed to Google

 

  Sky wonders  Seasons   Newsletter Contributors
    Extraterrestrial Climate      
    Clouds Winds Correspondents' April's 1000-mile paddle to the Arctic Ocean
    Extremes & freaks Forecasts   Weather forecast at any location April's mountain and desert life
    Atmosphere        
             
             
       

  Copyright 2007 by April Holladay