Most U.S. motorists will encounter the cheapest Labor Day weekend gas prices in four years, thanks to a downward trend that began in July, on the way to a possible drop to under $3 a gallon in November, GasBuddy predicted Wednesday. Cheaper global and domestic crude oil prices have pushed costs for North American refiners lower despite violence in the Middle East and uncertainty about long-term Russian energy supplies. “We expect to see stable gasoline prices from now through mid-September,” GasBuddy chief oil analyst Tom Kloza said in a news release. “Some more significant declines could come after Sept. 15. … By Veterans’ Day, we anticipate that much of the country could be looking at average prices below $3.25 gallon with thousands of stations under $3 gallon.” The average price in Maryland was $3.38 as of Wednesday, according to GasBuddy.com. GasBuddy, of Gaithersburg, tracks gas prices around the country.