Benoit, Robert (Recherche en Prevision Numerique Environnement Canada Dorval, Canada H9P 1J3)
Yau, M.K. (Dept of Atmospheric Sciences McGill University, Montreal, Canada)
Tremblay, Andre (Clouds Physics Environnement Canada Dorval, Canada H9P 1J3)
Gayrard, Frederic (Meteo-France CNRM F-31057 Toulouse Cedex, France)
Chamberland, Stephane (Recherche en Prevision Numerique Environnement Canada Dorval, Canada H9P 1J3)
Kouwen, N. (Civil Engineering U. of Waterloo Waterloo, Ontario, Canada)
One of the heavy orographic precipitation episodes of the MAP Phase I on numerical modelling study, the Brig flashflood of September 1993, has been examined in details with the non-hydrostatic model MC2. The role of the ice phase appears to be important for the accurate positioning of the damaging rain cells on the outer rim of the main precipitation "jet" arriving from the Mediterranean.
Three condensation schemes are compared: a comprehensive one with several classes of hydrometeors, a more efficient one with only equilibrium ice fraction, and a classical Sundqvist cloudwater scheme. All of the formulations are advective.
Once the meteorological aspect is satisfactory, it has been planned to simulate the extreme streamflows of the several neighbouring rivers affected by this event. The preparation of the hydrologic model running on a fine distributed grid with hourly outputs will be covered also.