A growing priority for the experimental NSSL Warn-on-Forecast System (WoFS) is the exploration of ensemble design strategies that will enable ~1-km data assimilation and/or forecast grids to be used in real-time. Downscaling 3-km analyses to ~1-km grids for the free forecast integration has shown some benefits (Lawson et al. 2020; Miller et al. 2022), but retaining 3-km grid spacing for the data assimilation is a potentially major limitation. Unfortunately, ~1-km ensemble data assimilation is currently prohibitively expensive. Multi-resolution data assimilation, where both high- and low-resolution members are used during cycling, offer a potential solution. Once a fully ~1-km WoFS becomes computationally feasible, multi-resolution data assimilation may enable still higher-resolution (e.g., 500-m grid spacing) analyses and forecasts.

Research proposals are invited on all aspects of multi-resolution data assimilation. Several years of warm season forecasts from the WoFS will be made available to the successful applicant.

Miller, W., C. K. Potvin, M. L. Flora, B. Gallo, L. Wicker, T. Jones, P. Skinner, B. Matilla, and K. Knopfmeier, 2022: Exploring the usefulness of downscaling free forecasts from the Warn-on-Forecast System. Wea. Forecasting, 37, 181-203.

Lawson, J. R., C. K. Potvin, P. S. Skinner, and A. E. Reinhart, 2021: The vice and virtue of increased horizontal resolution in ensemble forecasts of tornadic thunderstorms in low-CAPE, high-shear environments. Mon. Wea. Rev., 149, 921-944.