April natural gas prices reached their best levels in 2 1/2 weeks Monday, but late day weakness carried into the overnight and early morning hours. Some traders indicated that natural gas prices were able to shake off early reports yesterday from the National Weather Service that projected this week's heat-related demand for natural gas to be nearly 12% below normal. Meanwhile, cash prices managed to break a 3-day losing streak Monday, supported by a boost in industrial demand and the prospect of colder temperatures throughout the Mid US.