This dataset is provided by The Tomorrow Companies Inc. It contains L1-TBR V01-00 Tomorrow.io Microwave Sounder (TMS) observations, formatted for consumption in Joint Effort for Data assimilation Integration (JEDI) applications using the Interface for Observation Data Access (IODA) version 3 format (e.g., HofX, Variational). Observations are supplied from the TMS-S02 and TMS-S04 instruments during January 2025. Each file contains data from a one hour window. This is an addendum to a publication submitted for peer-review to the Quarterly Journal of the Royal Meteorological Society. This limited subset of an otherwise proprietary dataset provides all of the TMS data and metadata needed to replicate the experiments described therein. As a commercial mission, full access to the TMS datasets is otherwise restricted. Samples of the TMS level 1B-TBR products in their as-distributed format are available at https://www.tomorrow.io/satellite-data/data-catalog/l1b-tbr/. At the time of submission, additional data from TMS are under evaluation by NOAA's CWDP, and are available to academic and international partner institutions.