Status: Finalised Material from: Linus, Fernando


 



1. Impact

On 10 July severe convection hit parts of southern Europe. The media reported 6 fatalities as a result of a storm that hit the northern region of Greece, south of Thessaloniki. Several videos showed lightning, heavy rain (hail) and strong winds associated with the phenomena.


https://www.bbc.co.uk/news/world-europe-48945821

2. Description of the event


Unfortunately the data (obs) are scarce but one report (I assume is Thessaloniki airport) shows a wind speed of 30 kts with a gust of 42 kts ( ~22 m/s, see the map with the red arrow pointing to the location) at 19 UTC (21 LT).


The plots below show analyses of MSLP and 6-hour precipitation forecasts every 12h hour between 9 and 11 July.


The plots below show the analyses of z500 (contours) and t850 (shade) from 8 to 11 July.



The animation shown below is a sequence of hourly images of the RGB product from Meteosat where is visible a couple of convective cells moving with the upper level trough eastwards. One of these cells was responsible for the very unsettle weather conditions havoc in the central eastern regions.

3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The plots below show observations and forecasts of 24-hour precipitation valid from 10 July 06UTC to 11 July 06UTC.


3.3 ENS

The plots below show EFI and SOT for total precipitation valid 10 July.

The plots below show EFI and SOT for maximum CAPE valid 10 July.


The plot below shows the evolution of forecast for the grid point with maximum 24-hour precipitation valid 10 July for the 1x1 degree box outlined in the HRES plots above. The plot includes ensemble (blue box-and-whisker), HRES (red dot) and model climate (red box-and-whisker).

The plot below shows the same as above but for the 24-hour average CAPE in the box.


The plot below shows the evolution of forecast for the grid point with lightning activity over 24 hours valid 20 August for the 1x1 degree box outlined in the HRES plots above. The plot includes ensemble (grey box-and-whisker), HRES (red dot) and model climate (red box-and-whisker). It was a much elevated lightning activity in the forecasts issues the days before the event.

3.4 Monthly forecasts


3.5 Comparison with other centres


4. Experience from general performance/other cases


5. Good and bad aspects of the forecasts for the event


6. Additional material