Extended winter weather coupled with already-tight supplies of distillate— a petroleum product that can be processed into either heating oil or diesel fuel— will push diesel pump prices beyond current record highs, the Energy Information Administration (EIA) has warned.

This is an unusual development in the diesel market, as April is typically the month diesel prices decline as heating oil demand plummets, allowing for a buildup in distillate stockpiles. But this is not the case this time.

During the first week of April, wholesale diesel prices jumped on tightened distillate stock, which means at least two more weeks of new record high diesel prices, said Jacob Bournazian, EIA economist.

“You’d like to see those distillate stocks grow in April, but it hasn’t happened yet,” Bournazian, told Fleet Owner. “Prolonged cold weather has generated a sustained strong demand for distillate outside the winter heating season. Without a supply cushion, wholesale prices are jumping in response to any supply disruption. We expect to see a fallback in diesel prices, but probably not for a couple weeks.”

The average national price for a gallon of diesel rose to a new record high after a 5.4-cent increase to $2.303 per gallon last week. This marks the third consecutive week of new record diesel prices and nine consecutive weeks of price hikes from the $1.983 average posted on Feb. 7.

All regions posted an increase, but California posted the biggest jump, up 6.9 cents to $2.581. California also retains the crown for the most expensive region in which to fill up. The steadiest diesel prices were in the Rocky Mountain region, which posted only a 3.5-cent hike to $2.361. Bargain hunters may want to fill up in the Gulf Coast region if possible, as prices there at $2.24 were the lowest in the nation.

“There’s still a good five to 10 cents of further price increases yet to come,” Bournazian told Fleet Owner. “There are early signs this week that prices may not jump a another dime, and instead go up a nickel, but it’s still too soon to have a clear prediction.”

This is because the recent surge in wholesale diesel prices is still working its way down to the retail level, Bournazian explained. “Last week wholesale diesel prices jumped a good 15- to 20 cents. This reflects continued strong demand for heating oil against already low [distillate] inventory levels and tight supply conditions.

“We can reasonably expect [distillate] demand will really taper off in the end of April,” he said. “It will be then that you could see the industry make a real effort to build inventory.”

But even if there is a decline in diesel prices in late April, the delay in the seasonal distillate stock buildup cycle in the energy market doesn’t bode well for prices for when the next seasonal run-up in heating oil demand begins.

“When you have demand of this magnitude in the first week of April, it basically holds the industry’s ability to rebuild inventories in preparation for the next heating oil season,” Bournazian said. “The ability to rebuild stocks in the summer is key to keeping prices down when heating oil demand returns in the fall.”

So while prices may fall late this month, April may not mark the end of record high diesel prices.