Sep Nymex natural gas (NGU24) on Monday closed down by -0.066 (-3.26%). Sep nat-gas prices Monday moved lower for the fifth consecutive session and posted a 2-1/2 week low. Over the past week, nat-gas prices have been under pressure due to robust supplies and forecasts for moderate temperatures that will reduce nat-gas demand from electricity providers to run air conditioning. US nat-gas supplies as of August 16 were +12.6% above their 5-year average. The Commodity Weather Group said Monday that a short-lived heat wave for the Midwest and East Coast this week will give way to cooler temperatur…