Status:Ongoing analysis Material from: Linus
1. Impact
During the first week of October heavy rainfall hit southern Italy with accumulations of more than 400 mm in places. The case happened in the days after Medicane Zorbas (201809 - Rainfall - Zorbas).
Report on the event (in Italian): http://www.cfd.calabria.it//DatiVari/Pubblicazioni/rapporto%20di%20evento%2002_06%20ottobre%20%202018%20def.pdf
2. Description of the event
The plots below show analyses of MSLP and 6-hour precipitation forecasts every 12h hour between 1 and 6 October.
The plots below show analyses of z500 and t850 every 24 hour between 1 and 6 October. A trough deepened over Ligurian Sea and moved southward over the central Mediterranean during the period.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show observations and HRES forecasts of 24-hour precipitation valid from 4 October 06UTC to 5 October 06UTC.The maximum observation inside the outlined 2x2 degree box was 388 mm, and the mean of all observations in the box 120 mm, while the last forecast for the same sites was 18 mm, and a maximum of 53 mm.
3.3 ENS
The plots below show EFI and SOT for total precipitation valid 4 October.
The plot below shows the evolution of forecast for the grid point with mean 24-hour precipitation valid 4 October 06UTC to 5 October 06UTC for the 2x2 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). Note that the mean from the 17 observations inside the box was 120 mm.
3.4 Monthly forecasts
The plot below show the verification of weekly precipitation anomalies in extended-range forecasts valid 1-7 October. There was not much predictability beyond medium-range for this case.
