Actually if you are home and can do it---you should measure the 1.5" before it flipped to rain mid morning and note the 1.5" and LE, then report that as new snow the next morning. So new snow would be 1.5 to cocorahs with the snow LE. Now if you not home and couldn't measure the 1.5" and then it rained and it was .2" when you got home, then you would report .2"
From Cocorahs
One of the difficulties with accurate and consistent snowfall measurement is related to the melting, settling, or evaporation of snow before you have a chance to measure it (especially in the Fall and Spring). Please try to do a measurement as close in time to when the storm ends as possible. Don't wait until 7AM if the snow ended the previous day. During long-duration snowfalls, you may choose to measure and clear the snowboard every six hours. The total snowfall would then be the summation of the different measurements