The large-scale environment can have a significant impact on subtropical precipitating systems via the baroclinicity of the environment and the associated dynamical forcings. The degree of baroclinicity is examined using National Centers for Environmental Prediction (NCEP) reanalysis temperature and zonal wind fields over a two-year period for Southeast Texas, yielding classifications of barotropic, weakly baroclinic, and strongly baroclinic for the background environment. Weakly baroclinic environments accounted for half of the days throughout the two-year period. Barotropic environments occurred most frequently during summer and strongly baroclinic environments occurred most frequently in winter, although less often than weakly baroclinic environments. A climatology of storm types, based on dynamical forcing (i.e., weak forcing, drylines, cold fronts, warm fronts, stationary fronts and upper level disturbances) and precipitation structure (i.e., isolated, scattered, widespread, linear, unorganized and leading-line/trailing stratiform), was compiled and compared to the baroclinicity designations. Non-frontal storm types (i.e., weak forcing, drylines and upper level disturbances) are typical of barotropic environments, while frontal storm types (i.e.,warm, cold and stationary fronts) are typical of weakly and strongly baroclinic environments. Storm events and drop-size distributions (DSD) were identified from surface rainfall data collected by a Joss-Waldvogel disdrometer located in College Station, Texas. The DSDs were compared by baroclinicity and storm type. The barotropic DSD is weighted towards the largest drops because of the stronger convection and stratiform precipitation in the weak forcing and dryline storm types, while the strongly baroclinic DSD is weighted towards the smallest drops because of the weaker convection from the warm fronts and stationary fronts. The weakly baroclinic DSD is weighted more evenly towards small and large drops than the barotropic and strongly baroclinic DSDs because of the conflicting microphysical processes in the different storm types. The microphysical processes within the storms vary by storm type and baroclinicity regime, such that the large-scale environment modifies the precipitation characteristics of storms in SE Texas.

The large-scale environment can have a significant impact on subtropical precipitating systems via the baroclinicity of the environment and the associated dynamical forcings. The degree of baroclinicity is examined using National Centers for Environmental Prediction (NCEP) reanalysis temperature and zonal wind fields over a two-year period for Southeast Texas, yielding classifications of barotropic, weakly baroclinic, and strongly baroclinic for the background environment. Weakly baroclinic environments accounted for half of the days throughout the two-year period. Barotropic environments occurred most frequently during summer and strongly baroclinic environments occurred most frequently in winter, although less often than weakly baroclinic environments. A climatology of storm types, based on dynamical forcing (i.e., weak forcing, drylines, cold fronts, warm fronts, stationary fronts and upper level disturbances) and precipitation structure (i.e., isolated, scattered, widespread, linear, unorganized and leading-line/trailing stratiform), was compiled and compared to the baroclinicity designations. Non-frontal storm types (i.e., weak forcing, drylines and upper level disturbances) are typical of barotropic environments, while frontal storm types (i.e.,warm, cold and stationary fronts) are typical of weakly and strongly baroclinic environments. Storm events and drop-size distributions (DSD) were identified from surface rainfall data collected by a Joss-Waldvogel disdrometer located in College Station, Texas. The DSDs were compared by baroclinicity and storm type. The barotropic DSD is weighted towards the largest drops because of the stronger convection and stratiform precipitation in the weak forcing and dryline storm types, while the strongly baroclinic DSD is weighted towards the smallest drops because of the weaker convection from the warm fronts and stationary fronts. The weakly baroclinic DSD is weighted more evenly towards small and large drops than the barotropic and strongly baroclinic DSDs because of the conflicting microphysical processes in the different storm types. The microphysical processes within the storms vary by storm type and baroclinicity regime, such that the large-scale environment modifies the precipitation characteristics of storms in SE Texas.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Quantitative descriptions of regional differences of rainfall amounts and intensities in the southwest, such as depth-duration frequencies, generally have ignored differences in the storm system that generated the rainfall and have lumped essentially different storm systems together. Thunderstorm rainfall in southern Arizona and New Mexico were analyzed using data from both recording and standard rain gages. The results were somewhat conflicting. Possibly because of more frontal activity and less distance from the Gulf of Mexico., the thunderstorms in eastern New Mexico can be more intense than those in southeastern Arizona. Recording rain gage records suggest that air-mass thunderstorms produce a larger number of more intense short-duration (about 1 hour or less) rains in southeastern Arizona than in other parts of southern Arizona. However, standard rain gage records from southern Arizona indicate that rainfall from individual air-mass thunderstorms may be greater in south-central Arizona than in se or sw Arizona. But frequency analysis of standard gage data from air-mass storms shows that the 100-year point rainfall is about 3 inches in all 3 regions. With more data becoming available, especially from remote areas, more exact separation of thunderstorm types and a better definition of rainfall will soon be possible.