Gas prices jumped Friday to their highest level since June, a possible preview of what analysts believe will be a record spike in pump prices this spring. But the current price surge could be short-lived. While gasoline rose sharply in recent days in response to oil's dramatic climb to a new record above $101 a barrel, gas supplies have quietly grown to their highest level in 14 years. At the pump, gas prices rose 2.9 cents overnight to a national average of $3.115 a gallon, says AAA and the Oil Price Information Service. That was the highest since June 8.