12z March 10 2011 ECMWF Ensemble indicates a strong warm up may be in store for the Midwest and into the Upper Midwest.
With low pressure over Florida redirecting Gulf air into the Midwest, highs of into the 50's and 60s are quite likely.
12z ECMWF temperature anomaly also indicates strong warm air pushing into much of the US. The Weather Centre is predicting that, should the high pressure be stronger, the warm air advection may be stronger and more north.
Last but not least, 12z GFS Ensemble is indicating that low pressure with a warm front lifting north will bring the push of warm air north, possibly into extreme southern Canada.