September natural gas prices traded lower in early morning action and challenged Monday's low of $4.312. The natural gas market has come under pressure in recent sessions as the extreme heat seen last week eases and as air conditioning demand ebbs. Meanwhile, near record high temperatures in Texas are expected to move east in coming days, and that is a force that could support demand. There also appears to be a developing system in the Northeast Caribbean, which the National Hurricane Center estimates has a 20% chance of materializing into a tropical cyclone.