From 13Z 19 Feb 2018 to 12Z 21 Feb 2018, the NLDAS-2 hourly operational forcing "A" datasets had zero precipitation over all of CONUS and Mexico.
This error was a result of undefined values sent over from the operational CPC daily gauge analysis. Note that the 12Z 19 Feb 2018 field does have correct precipitation; the first incorrect hourly time is on 13Z 19 Feb, which represents the accumulated precipitation from 12Z to 13Z. These two days happened to be when heavy rains fell over the central U.S., centered around Illinois. On 12 June 2018, these 48 hourly files were replaced on the NASA GES DISC archive. The February 2018 monthly-averaged forcing "A" file was also replaced. Note that the NLDAS-2 LSMs are not corrected, and still reflect the zero precipitation from these two days in February 2018. For details about this issue, please see the "known issues" question/answer on the NLDAS FAQ.