As traders awaited the details on another hefty shoulder season storage injection, and with convincing signs of summer cooling demand yet to show up in forecasts, natural gas futures extended their losses early Thursday.

After giving up 6.1 cents in the previous session, the July Nymex contract was down another 5.2 cents to $2.214/MMBtu at around 8:45 a.m. ET.

Surveys suggest traders and analysts expect a triple-digit injection from the latest Energy Information Administration (EIA) storage report, scheduled for 10:30 a.m. ET. 

The print, which covers changes during the week ending May 26, is poised to further pad an already sizable inventory surplus versus the five-year average.

Estimates submitted to Reuters ranged from injections of 99 Bcf to 123 Bcf, with a median of...