On the GFS, which is not reliable for long term forecasting it is suggested that the heatwave could last in perpetuity. 500mb heights do not change much over the duration of 10 days. I could see this as a feasibility because the high pressure systems are on a predictable amplification cycle, and essentially what happens is that the subtropical high pressure system builds across northern Mexico , then hands off to the North Pacific high, then hands back off to the subtropical high pressure system. This is reflected on EC and GFS ensemble mean. The heatwave would be persistent with temperatures 8-15 degrees above normal, and as sea surface temperatures warm temperatures near the coast will likely bump up. There will be Gulf surges but because the ridge will be overhead convection could be shallow and suppressed. Bottom line is this looks like a very dangerous situation of long duration heat perhaps lasting for 10 days or more.
Any sort of fuel moisture excesses should be wiped out at all elevations.
