We propose to develop a framework to simulate urban-scale fires resulting from regional nuclear blasts. It will leverage data on urban morphology and results from simulations performed with a coupled urban-fire-atmosphere model to produce heat and aerosol emissions from burning cities. It will also simulate the evolution of resulting urban pyroconvective smoke plumes, as well as their vertical distribution and final injection level. The effort will leverage the existing fire-atmosphere model WRF-SFIRE-CHEM, which couples a fire spread model and the chemistry version of the Weather Research and Forecasting Model (WRF-Chem) linked with an advanced urbanized version of WRF. Existing wildfire spread and fuel consumption modules will be complemented by the urban fire model, leveraging detailed urban morphological information from the WUDAPT methodology to estimate urban fire heat and emission fluxes. The resulting urban-fire model will allow urban, meteorological, as well as fire processes and interactions, to be resolved in one integrated modeling framework. This will allow us to estimate vertical distributions of emission fluxes, plume rise, and smoke aerosol concentrations, and will allow NW modeling of groups of burning cities anywhere in the world, with simulated detailed characteristics of pyroconvection and emissions from urban fires initiated by nuclear explosions.