Radar
These are typical visualisations of radar measurements. The coloured signals represent precipitation of different rates. Radar is an important source for precipitation observation but must be treated carefully especially in mountaineous areas: there are many errors which cannot be avoided from the technique as such. Some of them can be excluded or can be taken into account with climatological measurements. But for other errors the forecaster has merely to know it.
The characteristics for an observation network (based on the weather service of Austria) are:
- Space resolution: depends on the system but is usually from 1 to 4 kilometers
- Time resolution: depends on the system but is quite often in the order of 5 minutes
- Forecast period: observations; are the input for a nowcasting of precipitation for the next few hours (2 hours)
Radar observations are input to different nowcasting models but work is more and more ongoing to implement those measurement also in LAM models.
"From what I have learned I got the feeling that with radar the precipitation obervation is more or less solved. Now I read about the many inherent errors?"
"Of course radar is a very important maybe in some areas the most important data source for precipitation, but there is till now no completely satisfying method for observing precipitation. At the time being, there is the overall opinion that the best precipitation analysis can be gained only from a combination of all relevant data sources (observations, radar, satellite data). But such a combination is a tricky task. We will look at it ina further session."
"Now, let's continue by examining satellite data. Follow
this link
to find out about that!"