Forecasters have issued a winter weather advisory for a portion of eastern Iowa in anticipation of snow that could cause slippery roads and reduced visibility. The advisory is in effect from 6 a.m. today to 6 a.m. tomorrow for an area that includes Delaware, Dubuque, Jackson and Jones counties. The National Weather Service is predicting 2 to 4 inches of snow accumulation in the affected area. Travelers can expect slippery road conditions, and patchy blowing snow could significantly reduce visibility at times. Travelers are advised to use caution when driving.