As traders contemplated a swelling storage surplus amid mild springtime temperatures, natural gas futures were down sharply ahead of the front month expiration Friday.

NGI Morning Natural Gas Price & Markets Coverage

With volume thin in its final day of trading, the May Nymex contract was off 9.9 cents to $1.539/MMBtu as of 8:35 a.m. ET. June was trading 5.5 cents lower at $1.931.

The U.S. Energy Information Administration (EIA) on Thursday reported a 92 Bcf injection into Lower 48 storage for the week ending April 19, higher than pre-report expectations. 

The build also outpaced historical norms and raised the surplus versus the five-year average to 655 Bcf, EIA data show.

When compared to degree days and normal seasonality, the latest EIA print implies balances were 0.3 Bcf/d tighter than the five-year average,...