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The figure below shows the 3-day accumulated precipitation in the box 44N-45N, 18E-20E from different initial dates (for control forecasts from different centres). In general UKMO seems to be able to produce most rain for the region.


The plots below show CDF for 5-day precipitation 12 May 06UTC to 17 May 06UTC for Beograd (point for 44.9N, 20.3E), for different centres obtained from the TIGGE archive. The observed value for the period was 190 mm.

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titleTIGGE CDF for Beograd

The plots below show CDF for 3-day precipitation 13 May 06UTC to 16 May 06UTC for Beograd, for different centres. The observed value for the period was 174 mm. Here the results are quite mixed

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titleTIGGE CDF for Beograd (3-day)

The plots below show CDF for 3-day precipitation 13 May 06UTC to 16 May 06UTC for Loznica (point for 44.3N, 19.1E), for different centres. The observed value for the period was 213 mm. Here UKMO outperformed all other centres. NCEP seems to have less spread for this point than the other dentres.

figure below shows the evolution of probabilities for >60 mm for the 3-day period 13 May to 16 May for the box 44-55N, 18-20E for ensemble forecasts from different initial dates (x-axis). We have to bear in mind here that one cannot evaluate a probabilistic forecast for one event, but the plot gives an indication of the strength of the signal. For the shortest forecasts, UKMO has the strongest signal, as expected from the CDF above. This could be due to a wet bias in their model, but it has to be evaluated further. NCEP had the bad forecast for 12 May 00UTC, which is also present in the ensemble.

ECMWF started to pick up a signal on 6 May together with UKMO. UKMO had a drop in the probabilities the day after, connected to a bad forecast on the European scale. One thing worth to mention is that all but one ECMWF HRES, control and T319 forecasts (as seen in HRES section) had the event from 8 May 00UTC and onwards (total 30 forecasts, 97% probability), but the ensemble probabilities for all but the last ensemble (13 May 00UTC) had probabilities below 80%. It could be interesting to investigate if it could be diagnosed further.

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The plots below show the CDFs for the TIGGE forecasts from the plots above (3-day precipiation for the area).

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TIGGE CDF for Loznica (
3-day
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precipitation for area

 

The plot below shows the CDF for 14 May 06UTC to 15 May 06UTC for Beograd (left 108 mm observed) and Loznica (right, 110 mm observed). On this short lead time only NCEP got high precipitation amounts for Beograd, while UKMO had a bad forecast (due to model spin-up or something else?). For Loznica CMC had the worst performance, while the other three centres were very similar.

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To conclude, the results are quite mixed comparing different centres. The outstanding results are the high precipitation for 3-days from UKMO for Loznica.

The figure below shows the evolution of probabilities for >60 mm for the 3-day period 13 May to 16 May for the box 44-55N, 18-20E for ensemble forecasts from different initial dates (x-axis). We have to bear in mind here that one cannot evaluate a probabilistic forecast for one event, but the plot gives an indication of the strength of the signal. For the shortest forecasts, UKMO has the strongest signal, as expected from the CDF above. This could be due to a wet bias in their model, but it has to be evaluated further. NCEP had the bad forecast for 12 May 00UTC, which is also present in the ensemble.

ECMWF started to pick up a signal on 6 May together with UKMO. UKMO had a drop in the probabilities the day after, connected to a bad forecast on the European scale. One thing worth to mention is that all but one ECMWF HRES, control and T319 forecasts (as seen in HRES section) had the event from 8 May 00UTC and onwards (total 30 forecasts, 97% probability), but the ensemble probabilities for all but the last ensemble (13 May 00UTC) had probabilities below 80%. It could be interesting to investigate if it could be diagnosed further.

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The plots below show the CDFs for the TIGGE forecasts from the plots above (3-day precipiation for the area).

GalleryincludeLabelcdf_3d_areasortcommenttitle3-day precipitation for areaaccumulation from UKMO, which could be related to the general frequency bias towards wet events (see http://intra.ecmwf.int/plots/d/inspect/_mo8_precip_inter/precip_inter/etspssfb!FB!Europe!10mm/24h!FMA_2014!12UTC!/ ). ECMWF seems to have picked up the signal one day before the other centres.

 

3.6 EFAS

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titleEFAS

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