The Relationship between EMEX Mesoscale Precipitation Feature Properties and Their Environmental Characteristics

Abstract

Characteristics of the prestorm environment of Equatorial Mesoscale Experiment (EMEX) mesoscale precipitation features (MPFs) are related to properties of them systems using regression analysis. Although environmental thermodynamic parameters are poorly correlated with EMEX MPF properties (mainly because environmental thermodynamic conditions varied little among MPFs), kinematic parameters are well correlated to these properties. Lines whose environments have low-level shear (the shear between about 950 and 750 mb) exceeding 5 m s?1 are oriented normal to the direction of this shear; lines where the low-level shear is under 5 m s?1 are oriented along the direction of the midlevel shear (the shear between about 800 and 400 mb). Convective line speeds correlate well with the maximum speed of the rear-to-front flow in the troposphere below 300 mb. Direction of MPF motion is nearly coincident with the tropospheric mean wind direction. convective line length is proportional to the magnitude of the men along-line wind in the cloud layer. The lower-tropospheric drying that a system causes is proportional to the shear within two different layers?800?400 and 1000?800 mb.