Natural gas spot prices at SoCal Citygate were trading as high as $25/MMBtu Tuesday, potentially setting a four-year high as colder temperatures drove up demand on utility Southern California Gas Co.’s (SoCalGas) imported-constrained system.

According to NGI’s MidDay Alert, day-ahead deliveries at SoCal Citygate were averaging $19.507 as of Tuesday afternoon, with a range of $12.000-25.000.

Tuesday’s high would represent the most expensive day-ahead trade at SoCal Citygate since Feb. 5, 2014, when prices traded as high as $30, Daily GPI historical data show.

The Los Angeles basin is expected to see temperatures around 10-12 degrees below seasonal norms through the end of the week, Genscape Inc. said in a note to clients Tuesday. Amid the unusually cold temperatures, SoCalGas system demand has risen above 3.7 Bcf/d, “its highest level this winter-to-date and the highest single-day since mid-January 2017,” according to Genscape.

Genscape analyst Joseph Bernardi further noted to NGI that SoCalGas is reporting daily storage withdrawals exceeding the 1 Bcf/d mark this week, “also for the first time in over a year.”

On Tuesday SoCalGas was projecting system demand to remain between 3.6-4 Bcf/d through the end of the work week, with daily receipts topping out at a little more than 2.7 Bcf/d.

“Import zone capacities continue running near max capacity, with less than 10% capacity available in the Northern Zone and less than 20% available in the Southern Zone,” Genscape said.

SoCalGas and San Diego Gas & Electric jointly declared a system-wide curtailment for electric generation customers starting Tuesday “due to forecasted low temperatures and expected high customer demand.

“…System conditions remain dynamic and are subject to change,” the utilities said. “Until further notice, a system-wide curtailment watch will be in effect for all other noncore customers. Customers are advised that they may be receiving a notice to curtail service.”

SoCal Citygate has been no stranger to price spikes in recent months. In late October, SoCal Citygate jumped $9 day/day to more than $12 amid higher demand and a combination of planned and unplanned pipeline outages. The point remained volatile — and traded at an elevated basis — for weeks afterwards.