Gas prices are down slightly this week across Arizona. Triple-A Arizona says the average price of gas fell about a half-cent this week to $2.89 a gallon. In Flagstaff, the average price of gas is down just over three-cents a gallon to $2.97. However, some stations in Flagstaff are selling gas for $2.73 a gallon and lower. In Prescott, the average price of gas is down just over a cent to $3.00 even. However, some stations there are selling gas for $2.85 and lower. Officials say barring unforeseen circumstances, prices at the pump are expected to decline in the coming weeks.