There is snow when total precipitation is 0

[henrylu2]

Hello,

I was analyzing my wrfout files (that are written hourly) and noticed that there seems to be snow even though the accumulated total precipitation up to that point is 0. I added RAINC+RAINNC to get total precipitation and compared it to a few snow related variables such as SNOWNC and SNOWH, and found that SNOWNC and SNOWH are non-zero despite there not being any precipitation. What's more perplexing is that the period that was analyzed is in May around the Montreal area of Canada.

My question is: how could the model output show that there is snow despite not having any precipitation?

Thanks for your help,
Henry

 

[Ming Chen]

Henry,
SNOWH can be derived from input data and it is understandable that it is not zero while rainc + rainnc is zero.
However, rainnc shouldn't be zero if there is snow.
Can you plot time series of rainnc and snownc at the points you mentioned? Thanks.