medex, mediterranean experiment on cyclones that produce high impact weather in the mediterranean...

MEDEX, MEDiterranean Experiment on Cyclones that produce High Impact Weather in the Mediterranean

WMOWorld Weather Research Programme

MEDEX IMPLEMENTATION

Agustí Jansà (*), INM, Spain

Pinhas Alpert, TAU, IsraelPhilippe Arbogast, Météo-FranceAndrea Buzzi, ISAC, CNR, Italy

James Doyle, NRL, USAVassiliki Kotroni, NOA, GreeceCliment Ramis, UIB, SpainEvelyne Richard, LA, FranceAntonio Speranza, Univ. Camerino, Italy

And Members of MEDEX Advisory Group

(*) [email protected]



General objective of MEDEX:

The improvement of knowledge and forecasting of the cyclonesthat produce high impact weather in the Mediterranean area

Specific objectives (MEDEX phase 1, 2001-2004):

(a) To implement a dynamic climatology of the cyclones that produce high impact weather in the Mediterranean, to know the types of cyclonic structures that appears related to high impact weather events, if any. This is a necessary step to evaluate the potential impact of the improvement of the forecasting of cyclones on the prediction of the high impact weather itself. It is also necessary to know how representative is the work done on the base of a selection of particular cases.

(b) To determine and rank the multiple geographical and meteorological factors that are acting in the generation and evolution of the different types of cyclones that produce high impact weather in the Mediterranean.

(c) The identification of sensitive areas where better initial conditions may likely lead to improved forecasts. Closely connected with the former objective is an assessment of the impact of additional observations in sensitive areas.

Based on systematic data, covering every day along a period

Based on selected cases



Priority tasks for MEDEX phase 1

(according the WWRP/SSC Resolution about MEDEX, Sep. 2000)

a. Identify the nature, availability, and usefulness of data presently not available on the GTS, and to start concentrating these data in a MEDEX database.

b. Identify a set of cases where high impact weather was poorly forecast and conduct co-ordinate, in-depth case studies that include considerations of forecast skill and societal impacts associated with both the event and the poor forecasts.

c. Conduct NWP studies to identify sensitive areas where the addition of observations would most likely lead to improved forecasts and their related benefits.

d. Conduct research to identify physical and dynamical hypotheses that might form the basis of developing improved forecast techniques for Mediterranean cyclones.



Identify the nature, availability, and usefulness of data presently not available on the GTSEstablishment of the MEDEX database

Steps:1. Definition of data requirements (made, preliminarily)2. Identification of available data (made, preliminarily)3. Implementation of the MEDEX database (under study the feasibility of implementation

of the database in INM-Spain)

MEDEX objective Type of data Area Details

Dynamical climatology

Rainfall and wind Inner Mediterranean All peak values that overpass defined thresholds, since 1995.

Analysed fields Inner Mediterranean (at least) 4 daily at standard levels, al least since 1995.

Sensitivity to factors (validation)

Rainfall and wind Inner Mediterranean All data in the affected area for selected events only.

Radar and other non-conventional

Inner Mediterranean All data in the affected area for selected events only.

Impact of observations

Upper air data Outer Mediterranean (Eastern Atlantic incl.)

All data in sensitive areas for selected events only.

Surface data Outer Mediterranean (mainly inner area)

All data in sensitive areas for selected events only.

1. Definition of data requirements (made, preliminarily)

P 80W 20RADAR 1SYNOP 10



P 163W 10RADAR 1LIGHT.


P 1381W 76RADAR 7LIGHT.SYNOP 191

P 850W 80RADAR 2LIGHT.SYNOP 60

P 29W 29SYNOP 40PILOT 7TEMP 1

P 49W 27RADAR 1

P 96W 34RADAR 1

P 175W 50

non-GTS data availability



Specific objective 2

Diagnostic studies and sensitive experiments (selected cases)

Selection of cases 1995-2002(This work is a necessary step for Diagnosis studies and sensitive experiments concerning factors, as well as for Identification of sensitive areas).

The point of departure has been a questionnaire submitted to the institutions that are participating in MEDEX.

Selection criteria: High impact weather (mainly precipitation and wind) associated with cyclones

affecting the Mediterranean area Poor forecast skill Adverse societal impact and possible mitigation depending on forecast skill Sensitivity to initial condition and meteorological model used Data base accessible (meteorological non GTS data, documentation on adverse

weather impact and losses) Events affecting more than one country (to favour interactions) Events associated with different cyclone types and representative of all the

Mediterranean subregions





Selection of cases 1995 - 2002

More then 80 events were initially suggested by 17 institutions of 11 countries. 27 among them constitute the present selection. The pre-selection has been made according the following criteria:

1.Events affecting two or more contiguous countries.

2.Severe impact weather events (affecting one country only).

3.Additional events to ensure some degree of geographical 'balance'.

NOTE: Information about societal impacts, degree of success of numerical forecasts and alerts is not always readily available, but a distinct progress was made in two iterations.



Geographical cover of selected events





Selection of cases : emerged forecasting problems:forecasting problems:

• Forecast often difficult but skill gradually improving in time

• Heavy precipitation (and consequences, mainly floods and

landslides, also snow) most important, but also strong winds

(damages, navigation, storm surges…)

• Most of benefits from meteorological models (especially LAM's):,

ECMWF, U.K.M.O., DWD (Europa, LOKALL M.), ARPEGE,

ALADIN, BOLAM, QBOLAM, ETA, HIRLAM, LAMBO, MASS, MM5,

RAMS...)

• Identification of problems limiting forecast skill.





Develop/test physical and dynamical hypotheses to form the basis of improved forecast techniques for Mediterranean cyclones

Investigate the physical role (in the formation and evolution of cyclones that produce high impact weather in the Mediterranean) and model representation /assimilation of:

• orography • surface fluxes of latent and sensible heat• latent heat release • upper level potential vorticity• low level jets





13/11/1999 00Z - ECMWF analysis

BO

LA

ME

CM

WF

Case study by Delitala et al. (SAR - Sardinia)(impact of high res. forecast of precip., also ensemble fc.)





Case study by Romero et al. (UIB, Palma de M.)applying piecewise PV inversion technique

PLINIUS CONFERENCE ON MEDITERRANEAN STORMSPLINIUS CONFERENCE ON MEDITERRANEAN STORMS Two rotating upper-level positive PV anomalies

Strong low-tropospheric warm advection

Track, shape and intensity of the surface cyclone and the corresponding rainfall pattern are very sensitive to the embedded upper-level PV anomalies





Example of MEDEX-related activities at the National Example of MEDEX-related activities at the National Observatory of Athens (Kotroni, Lagouvardos)Observatory of Athens (Kotroni, Lagouvardos)

OBSERVATIONS

Eta/NMC

100 km

*

RAMS

*

***

**

*

15/00

15/06

15/12

15/18

16/00

16/06

16/1216/12

16/12

16/06

16/06

16/00

15/18

15/00

15/00

15/06

15/1215/12

15/18

15/06

16/00

15/06

15/12

15/18

16/00

16/06

16/12

BOLAM

14-17 January 1995 multi-model case-study14-17 January 1995 multi-model case-study





Severe flood event of NW Italy, 13-16 Oct. 2000:example of hydrological-meteorological model coupling

(ISAO Bologna, Univ. of Genova, Univ. of Brescia)

Accumulated precipitation exceeded 700 mm/96 hrs and 550 mm/48 hrs (14-15 Oct. 2000)

Previsione di piena con il modello DIMOSOP - EVENTO 2000 misure pluviometriche dal 2000 10 12 12:00 UTC - Toce a Candoglia

(1532 km²)

0

1000

2000

3000

4000

12/10/20000.00

13/10/20000.00

14/10/20000.00

15/10/20000.00

16/10/20000.00

17/10/20000.00

Tempo [UTC]

Por

tata

[m

³/s]

0

5

10

15

20

25

30

35

40

Pre

cipi

tatio

n [m

m h

-1]

pioggia BOLAM pioggia pluviometri

Idrogramma osservato Idrogramma BOLAM

Idrogramma pluviometri

Observed and hindcasted runoff at Toce Candoglia, using the DIMOSOP hydrological model, based on BOLAM forecasts for the period 2000-10-13 to 200-10-17




Identification of sensitive areas for selected cases

The objective is to identify areas where better initial conditions may lead to improved forecast of events of high impact weather connected with cyclones.

1. The MEDEX project favours the case study approach on regional scale.

• The computation of sensitivities requires adjoint model code.

• In the case of the Mediterranean area, it is expected that diabatic

processes will need to be included in the adjoint calculations.

• Preliminary to OSSE experiments and to identification of

observational needs.



The EUCOS study on Climatology of Sensitive Areas (Marseille & Bouttier, 2000) give us an idea about were are the most sensitive areas for Southern Europe

6th Session of the Science Steering Committee for WWRP – Oslo, 15-19 Sep. 2003

Responses to SSC/WWRP recommendations:

• use the ERA40 reanalyses as quickly as possible to augment the cyclone data base.

• invite societal and economic experts to take part regularly in MEDEX committee discussions


References in the list of selected cases (MEDEX DB) [example]


(From Homar & Stensrud, 2003)


The MEDEX Data Base

02468

10121416

10/1

1/01

-00

10/1

1/01

-06

10/1

1/01

-12

10/1

1/01

-18

11/1

1/01

-00

11/1

1/01

-06

11/1

1/01

-12

11/1

1/01

-18

12/1

1/01

-00

12/1

1/01

-06

12/1

1/01

-12

12/1

1/01

-18

13/1

1/01

-00

12/1

1/01

-18

13/1

1/01

-00

13/1

1/01

-06

13/1

1/01

-12

13/1

1/01

-18

14/1

1/01

-00

surface circulation Upper/lower ratio

This other example shows the evolution of the surface circulation and of the ratio between upper and lower level circulations during the evolution of the main cyclone associated to the high priority selected case of 9-13 Nov 01:

In this case, the main cyclogenesis seems to have important low level contribution, later increasing the upper level weight.



Work in progress on MEDEX case studies: HYDROPTIMET (Interreg III - MEDOCC)

BOLAM, 18 km

94 mm

BOLAM, 6 km

134 mm

MOLOCH, 2 km

162 mm

La Garde flood event, France, 9/9/2003



Work in progress on MEDEX case studies: HYDROPTIMET (Interreg III - MEDOCC)

BOLAM, 18 km

104 mm

BOLAM, 6 km

116/102 mm

Catalunia flood, 10/6/2000

Application of a nudging Application of a nudging procedureprocedure

for rainfall assimilationfor rainfall assimilationto the 2001 Algerian Floodto the 2001 Algerian Flood

S. Davolio and A. BuzziISAC - Institute for Atmospheric Sciences and Climate

CNR - National Research Council [email protected]

INSTITUTE OF ATMOSPHERIC SCIENCES AND CLIMATE , ISAC-CNRINSTITUTE OF ATMOSPHERIC SCIENCES AND CLIMATE , ISAC-CNR

5th Plinius Conference on Mediterranean Storms Ajaccio,

Corsica, France 1–3 October 2003

ResultsResults

C F

Different rainfall patterns over the coast and south of the Balearic IslandsRain band missing in the forecast runRain band and area of light rainfall around Sardinia

Impact on cyclone development and evolutionImpact on cyclone development and evolution

C F

12 hours after the end of the assimilation

medex, mediterranean experiment on cyclones that produce high impact weather in the mediterranean...

Documents

mediterranean cyclones

high impact weather

mediterranean experiment

potential impact

forecasting of cyclones

medex database steps

conduct research

different types of cyclones