SPRING JUMP IN GAS PRICES PREDICTED FOR SOUTHLAND.

Byline: Staff and Wire Reports

While an ample supply of gasoline has kept prices relatively low all winter, filling up the tank could become more expensive before too long - as much as a quarter above the current average in the Los Angeles area.

The anticipated springtime increase should be less extreme at its peak than in recent years, though, because a gallon of gas costs 25 percent less today than it did a year ago.

Analysts say prices could begin to rise as early as mid-March, when refiners shift production from winter- to summer-grade fuel in preparation for the country's busiest driving season.

In Los Angeles, the average price of a gallon of gasoline is $1.30. Jeffrey Spring, spokesman for the Automobile Club of Southern California, said he expects prices to swell to between 15 cents and 25 cents by spring.

``We don't think we'll see the same price increases witnessed in previous years,'' he said. Last year saw gas prices well above $2 a gallon in Southern California and even higher in other parts of the country.

For refiners, the switch to cleaner-burning gas requires shutting down equipment, scrubbing it clean and starting all over again - a process that causes supplies to contract and prices to move higher, if only temporarily.

Refiners with excess winter-grade gas can blend in chemicals needed to meet summer air quality specifications, dump the product on the market at cut-rate prices or keep it in storage until next year. No matter which route they choose, the excess inventory will quickly disappear.

Once the switch is complete, the next phase in America's cyclical gas markets - regional price spikes - should not be far behind, analysts said. Spikes have been routine in recent years in California, the Midwest and parts of the Northeast as buyers bid up prices on the wholesale markets, fearing shortages of a special blend of federally mandated fuel, known as reformulated gasoline, which produces less smog.

With these market forces just around the corner, many analysts believe petroleum markets will exhibit a familiar volatility in the weeks and months ahead despite 6 percent more gasoline inventory than last year and weaker consumer demand.