MadSci Network: Earth Sciences
Query:

Re: How do meteorologists predict the weather?

Date: Mon Apr 2 05:32:23 2001
Posted By: Nezette Rydell, forecaster,National Weather Service
Area of science: Earth Sciences
ID: 985053437.Es
Message:

A meteorologist needs to know only two things to make a forecast...what the 
weather is at the moment and how the atmosphere behaves.  Sounds simple, 
right?  

Knowing the state of the atmosphere at a given time involves taking 
simultaneous observations at many points on the surface of the earth, as 
well as in the layers of air above the surface.  Surface observations are 
taken every hour at airports and other sites across the United States and 
every six hours around the world, including ships at sea and tethered buoys 
in the ocean.  These amount to over 3000 observations every hour.  Twice a 
day, at 0000Z and 1200Z (read about Zulu time at USATODAY), upper air 
observations are made using balloons, pilot reports, special upward-looking 
radars called profilers, and satellite sounders.     

Knowing how the atmophere behaves involves the study of atmospheric 
physics.  The atmosphere conforms to the physical laws of nature and over 
the years, atmospheric scientists have described this behavior using 
numerical equations.  Meteorologists study these laws and equations to 
understand why the atmosphere behaves the way it does, and to build 
computer models of the atmosphere.  

Forecasts can be made by a variety of methods.  Some methods move the 
weather from one region to another with little change in the weather 
pattern as it moves.  Some methods use computer models to change the 
weather patterns in time as well as space. You can read about these and 
others at this page from a class at 
Texas A&M University.

Forecasters take all of what they know about the state of the atmosphere at 
a point in time (the observations) and feed this information into computer 
models.  These models then step forward in time, changing the modeled 
atmosphere according to the way the equations say the real atmosphere 
should change.  The forecaster then takes what the model says, evaluates 
it, modifies it where he or she thinks necessary, and translates it into 
pictures and words you see and hear on the internet, radio, and TV.  

You can learn more about computer models and weather forecasting at the National Weather Service's 
Hydrometeorological Prediction Center, and USATODAY's weather 
pages.  


Current Queue | Current Queue for Earth Sciences | Earth Sciences archives

Try the links in the MadSci Library for more information on Earth Sciences.



MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci


MadSci Network, webadmin@www.madsci.org
© 1995-2001. All rights reserved.