The medium range forecast products include surface pressure patterns, circulation centers and fronts, daily maximum and minimum temperatures and anomalies, probability of precipitation in 12-hour increments, total 5-day precipitation accumulation for the next five days, and 500 hPa ( mb ) height forecasts for days 3-7.
22.
A . When the National Weather Service forecasters use the term " probability of precipitation, " they mean that in 10 instances of weather patterns similar to the one they are looking at, it rained five times, said Sam Perugini, a meteorologist at Pennsylvania State University.
23.
If they were indedpendent, then the probability of precipitation over Tuesday or Wedesday, P ( T \ or W ) = P ( T ) + P ( W )-P ( T ) * P ( W ), however the assumption of independence is a bad one for this kind of real world process . talk ) 17 : 17, 8 July 2008 ( UTC)
