EUMeTrain: Nowcasting CAL Module - Forecasting Material and Methods

Observations

The observations are input to numerical models, to national analyses and as the basis for a local very short range forecast (up to 12 hours) as well as for nowcasting (up to 6 hours). The difficulty lies in the relatively high space resolution and of course in the measurement errors as they appear for instance with precipitation.

The characteristics for an observation network (based on the weather service of Austria) are:

 

"If there is such a bad spacial resoltion of observation stations how do you get good values for locations in between? Can you merely interpolate?"

"Yes, you found exactly the weakness. A mere interpolation will in most cases not be correct. You must take into account orography and possibly other relevant data sources. So parameters like radar and satellites but also the model analyses have to be combined to get an optimum analysis and we think that we can get close to the (not known) reality. But you never will arrive at a complete correct analysis."

"The next set of data is Radar. Follow this link to learn more!"