Archive for June, 2013
Just a quick heads up: The Water Science Alliance has a blog: the “water science blog“! The goal of the Water Science Alliance is to “Water Science Alliance is to create synergies between the different water research institutions in Germany and the development and elaboration of interdisciplinary thematic clusters of German water research on the national and international level.”
I followed the weather prediction for the city of Stuttgart between June 3rd and June 11th a little closer. Amongst other sites, I checked the GFS ensembles at wetterzentrale for the city of Stuttgart at seven snapshots in time.
The charts show 20 GFS runs in different colours for temperature at 850hPa (top portion) and 6h-precipitation (bottom portion). In the images I flagged June 15th with a vertical orange line.
At the beginning there seems to be quite good agreement in both temperature and precipitation for the next three to four days.
The prediction from June 4th predicts a temperature decrease on June 10/11, together with significant precipitation. This temperature decrease is not anymore predicted on the 5th, but is predicted again on the 7th.
A significant drop in temperature happened on the 14th, together with a precipitation event, which was not predicted until the 10th.
This is only one example, analyzed by a non-meteorologist. But despite ensembles there is a lead-time of about three days. This also did not change when looking at other models.
It has been raining quite a bit over the last weekend. The German Weather Service is reporting on its homepage at some stations (Aschau-Stein, Kreuth-Glashütte) ~400L per square meters within 90hours (3.75 days). As a comparison, the annual precipitation sum for Cologne is ~800L per square metre.
This has led to some extreme water levels, for example in Passau:
The magic water level for the city of Passau is 12,55m, which has been exceeded for the first time since the year 1501AD (don’t ask me what this really means, since most likely there has been some change in the river’s regime over the years…)
The comparison pre-flood and currently looks quite impressive:
Generally, the East and the South is affected. For example, a major highway close to lake Chiemsee is closed for traffic. Some people have kept their sense of humour, surprisingly:
update Tuesday; June 04, 2013:
Here is a comparison of the gauged water height at the station Passau in the Danube. The white bars occur when there was no measurement due to the destruction of the gauge. Since this accident happened, the responsible agency is “taking individual measurements” according to their website. Also interesting, the actual peak water hight was higher and later than predicted 24 hours before.