Status: Finalised Material from: David L., Linus


 



1. Impact

During the week beginning Monday 7th November 2016, heavy precipitation and flooding occurred in the southeast of Europe. Countries including Albania and Greece were affected, with two fatalities recorded in Albania.

2. Description of the event

A deep trough located over western Europe caused a strong south-westerly flow (and moisture flux) across North Africa and the Mediterranean Sea to affect southeast Europe. This flow hit the steep orography along the shores of the eastern Adriatic Sea causing large precipitation totals. From the analysis of the ECMWF forecast system, the precipitation appeared to be more convective in nature.


The plots below show the analyses of z500 and t850 before and during the event.


 

 6-day accumulations of precipitation for various places in Montenegro, thanks to Branko Micev:

 

November
2016.

Accumulated precipitation
from 6 to 12 November 2016
in Montenegro
(mm)
Kolasin427
Cetinje378
Savnik312
Niksic259
Podgorica239
Plav203
Berane175
Ulcinj157
Andrijevica157
Zabljak148
Bijelo Polje143
Pluzine139
Bar129
Rozaje120
Budva105
Herceg Novi100


3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The HRES forecast captured the event, as shown by the precipitation verification below.


The precipitation verification for 06UTC 8th to 06UTC 9th November 2016. The shaded contours are the 42-66 hour precipitation forecast totals taken from the 12UTC 6th November 2016 initialisation.

3.3 ENS

The signal for the event was clearly seen in the ensemble prediction system, as shown in the meteograms below.


(Left) Meteogram from forecasts initialised at 00UTC 31st October 2016.
(Right) Meteogram from forecasts initialised at 00UTC 7th October 2016.

The plots below shows the EFI and SOT for precipitation valid 6-9 November.


3.4 Monthly forecasts

 

The event had high predictability with the monthly forecasts exhibiting a signal in week-2 (left figure) and week-3 (right figure).



(Left) ECMWF week-2 forecasts for a point in southeast Europe from 00UTC 31st October 2016.
(Right) ECMWF week-3 forecasts for a point in southeast Europe from 00UTC 27th October 2016.

3.5 Comparison with other centres


3.6 EFAS

The EFAS forecasts had a consistent signal for the flooding from about a lead time of 7 days. Please find below an example hydrograph valid for Albania.


Output from EFAS for the 12UTC 1st November 2016 forecast. The river basin is the Moraca in Albania.

4. Experience from general performance/other cases


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

This hydrological event had high predictability and was well captured by the ECMWF forecast system.

6. Additional material

 Status:Ongoing analysis Material from: David L., Linus


 



1. Impact

During the week beginning Monday 7th November 2016, heavy precipitation and flooding occurred in the southeast of Europe. Countries including Albania and Greece were affected, with two fatalities recorded in Albania.

2. Description of the event

A deep trough located over western Europe caused a strong south-westerly flow (and moisture flux) across North Africa and the Mediterranean Sea to affect southeast Europe. This flow hit the steep orography along the shores of the eastern Adriatic Sea causing large precipitation totals. From the analysis of the ECMWF forecast system, the precipitation appeared to be more convective in nature.


The plots below show the analyses of z500 and t850 before and during the event.


 

 6-day accumulations of precipitation for various places in Montenegro, thanks to Branko Micev:

 

November
2016.

Accumulated precipitation
from 6 to 12 November 2016
in Montenegro
(mm)
Kolasin427
Cetinje378
Savnik312
Niksic259
Podgorica239
Plav203
Berane175
Ulcinj157
Andrijevica157
Zabljak148
Bijelo Polje143
Pluzine139
Bar129
Rozaje120
Budva105
Herceg Novi100


3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The HRES forecast captured the event, as shown by the precipitation verification below.


The precipitation verification for 06UTC 8th to 06UTC 9th November 2016. The shaded contours are the 42-66 hour precipitation forecast totals taken from the 12UTC 6th November 2016 initialisation.

3.3 ENS

The signal for the event was clearly seen in the ensemble prediction system, as shown in the meteograms below.


(Left) Meteogram from forecasts initialised at 00UTC 31st October 2016.
(Right) Meteogram from forecasts initialised at 00UTC 7th October 2016.

The plots below shows the EFI and SOT for precipitation valid 6-9 November.


3.4 Monthly forecasts

 

The event had high predictability with the monthly forecasts exhibiting a signal in week-2 (left figure) and week-3 (right figure).



(Left) ECMWF week-2 forecasts for a point in southeast Europe from 00UTC 31st October 2016.
(Right) ECMWF week-3 forecasts for a point in southeast Europe from 00UTC 27th October 2016.

3.5 Comparison with other centres


3.6 EFAS

The EFAS forecasts had a consistent signal for the flooding from about a lead time of 7 days. Please find below an example hydrograph valid for Albania.


Output from EFAS for the 12UTC 1st November 2016 forecast. The river basin is the Moraca in Albania.

4. Experience from general performance/other cases


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

This hydrological event had high predictability and was well captured by the ECMWF forecast system.

6. Additional material