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Discussing the properties of weather in Tunisia, the Aladin and Arpege models, missed and well-forecasted situations, challenges, and expectations for meteorological forecasting improvement.
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Tunisian National Institute of Meteorology ALADIN Forecasters Meeting
Introduction Experiences - Missed situation by Aladin model - Well-forcasted situation by Aladin Challenges Expectations Plan
Introduction - Properties of weather in Tunisia - Availables models
Properties of weather in Tunisia The classic disturbances are North-West ones : a core of lower geopotential field is formed on Greenland, advance towards the British Isles and France. Arriving on the Mediterranean and associated with the Gene’s Golf of or Lyon’s Gulf depression, the minimum advances to Tunisia while absorbing moisture from the sea. Theses situations caused rains on northern and central Tunisia locally.
Modelsavailables ARPEGE model • There are three versions of ARPEGE model which are availables on SYNERGIE station. • The most usable one is the model which runs with a resolution of 50 kilometers. • It offers many parameters than others models which are available on SYNERGIE station.
ALADIN TUNISIA • This model has been declared operational since 2004. • The model runs with a resolution of 12.5 kilometers. • It offers many parameters than others models which are available on SYNERGIE station.
Experiences Missed situation by Aladin : The case of 19/05/2014 • 5 death in Kairouan • 45 mm in 3 hours • Wind gusts (104 km/h) • Hail in Mahdia and Mounastir Source of picture : http://tn.webradar.me/
Informations provided by ALADIN and ARPEGE Model The cumulative rainfall provided by the two models
We can note that the two models were unable to predict the best localisation for the intensive rains • also, they were unables to predict the exact quantities for the rains • On southern Tunisia we had just stored 2 mm in Remeda, for the others places there are praticly no precipitations.
Well-forcasted situation by Aladin19/09/2013 - disruptions in traffic • water infiltration in homes, commercial buildings and public facilities • 91 mm was stored in sfax Source : http://directinfo.webmanagercenter.com/
Informations provided by ALADIN and ARPEGE Model The cumulative rainfall provided by the two models
We can note that Aladin model was better than ARPEGE in point of view localisation and quantification for the intensive rains On northern Tunisia we had stored quantities of rain which were not forcasted by two models Generally, in convective situations, ALADIN model is not so bad. But in situations of frontal thunderstorms, it can find big problems
CHALLENGES We are in the obligations to work with praticly 3 models : - ARPEGE to make short-term forecasts. - ALADIN to neat and define our forcasts. - ECMWF to prepare medium-term forecasts.
EXPECTATIONS • To get more outputs of model to properly analyze weather situations. • To have a meteorological radar that helps us certainly in the immediate forecast. • To have others models with differents properties which will allow us to better studying meteorological situations.
Products of arome and aladinmodels for the situation of 19/05/2014
Products of arome and aladin models for the situation of 19/09/2013