http://www.federalreserve.gov/releases/cp/
It appears that commercial paper market participants couldn't get to work today. Twenty inches of snow in NYC shut down most of the transportation. There were even abandoned buses on the impassable streets of the city.

The Fed's CP graph came with this elaborate disclaimer, "Trade data insufficient to support calculation of the 15-day AA nonfinancial, 30-day AA nonfinancial, 60-day AA nonfinancial, 90-day AA nonfinancial, 1-day A2/P2 nonfinancial, 7-day A2/P2 nonfinancial, 15-day A2/P2 nonfinancial, 30-day A2/P2 nonfinancial, 60-day A2/P2 nonfinancial, 90-day A2/P2 nonfinancial, 7-day AA financial, 15-day AA financial, 30-day AA financial, 60-day AA financial, 90-day AA financial, 1-day AA asset-backed, 7-day AA asset-backed, 15-day AA asset-backed, 30-day AA asset-backed, 60-day AA asset-backed, and 90-day AA asset-backed rates for December 24, 2010. "