Jeremy Piger is an Assistant Professor of Economics at the University of Oregon. He has put together a model that presents recession probabilities for the United States "obtained from a dynamic-factor markov-switching model applied to four monthly coincident variables: non-farm payroll employment, the index of industrial production, real personal income (excluding transfer payments), and real manufacturing & trade sales.
It is a simple but robust model with a good track record of providing a modest advanced warning of recessions. Its updated quarterly.
Here is the prior Recession Probabilities for the United States. Note that this model gave a short warning prior to actual recessions beginning:
Graph courtesy of Jeremy Piger
Note: The main weakness in the model is the reliance on government data (which tends to be revised downwards eventually. See this chart of NFP vs B/D as an example.