Essex County, heads up! The National Weather Service said the northeastern corner of the state could get as much as nine inches of snow, part of a wintry system expected to flow into Maine and New Hampshire later Wednesday and remain into Thursday. Advertisement “It is possible this band of snow will graze Northeastern Massachusetts yielding advisory to warning-level snows with potential amounts ranging around 3 to 6 inches, possibly as high as 9 inches,’’ forecasters wrote. However, forecasters stressed that conditions may change over the next several hours, pushing snowfall amounts down or resulting into a changeover to rain. “Confidence is moderate at this time,” forecasters wrote in a winter story advisory for the region. “This headline will either be dropped or upgraded to an advisory or warning.’’ Get Fast Forward in your inbox: Forget yesterday’s news. Get what you need today in this early-morning email. Sign Up Forecasters also said strong, sustained winds of 30 miles an hour, with gusts up to 45 miles an hour, are expected on Cape Ann on the North Shore and south on the Cape and Islands. In Greater Boston, the weather system is expected to bring rain starting Wednesday afternoon, continuing into the Thursday. Daytime temperatures will reach the 40s in Greater Boston before dropping into the 20s overnight. Advertisement Sunny and dry weather with day time temperatures in the 40s are expected for the rest of the week, forecasters said. Forecasters also said strong, sustained winds of 30 miles an hour,…more detail