Residential solar photovoltaic (PV) systems are becoming increasingly common around the world. Much of this growth is attributed to a decreasing cost of solar PV modules, reduction in the cost of installation and other "soft costs," along with net-metering, financial incentives, and the growing societal interest in low-carbon energy. Yet this steep rise in distributed, uncontrolled solar PV capacity is being met with growing concern in maintaining electric grid stability when solar PV reaches higher penetration levels. Rapid reductions in solar PV output create an immediate and direct rise in the net system load. Demand response and storage technologies can offset these fluctuations in the net system load, but their potential has yet to be realized through wide-scale commercial dissemination. In the interim these fluctuations will continue to cause technical and economic challenges to the utility and the end-user. Late-afternoon peak demands are of particular concern as solar PV drops off and household demand rises as residents return home. Transient environmental factors such as clouding, rain, and dust storms pose additional uncertainties and challenges. This study analyzes such complex cases by simulating residential loads, rooftop solar PV output, and dust storm effects on solar PV output to examine transients in the net system load. The Phoenix, Arizona metropolitan area is used as a case study that experiences dust storms several times per year. A dust storm is simulated progressing over the Phoenix metro in various directions and intensities. Various solar PV penetration rates are also simulated to allow insight into resulting net loads as PV penetration grows in future years.