Solar irradiance, the energy from the Sun's electromagnetic radiation, has a wide range of applications from meteorology to agronomy to solar power. Solar irradiance is primarily determined by a location's spatial relationship with the Sun and the atmospheric conditions that impact the transmission of the radiation. The spatial relationship between the Sun and a location on Earth is determined by established astronomical formulas. The impact of atmospheric conditions may be estimated via proxy using pixels from satellite imagery. While satellite-based irradiance estimation has proven effective, availability of the input data can be limited and the resolution is often incapable of capturing local weather phenomena. Brief qualitative descriptions of general atmospheric conditions are widely available from internet weather services at higher granularity than satellite imagery. This methodology provides logic for quantifying the impact of qualitative weather observations upon solar irradiance, and the integration of this methodology into solar irradiance estimation models.