RE: assumptions and whyResearcher, I think you are missing what I am saying. If you want to take annual averages you have to account for swings throughout the year, unless the monthly averages are also the same. As a simple mathematical example shows below, assume the following daily averages:
Jan-Mar 65 BCF
Apr-Jun 60
Jul-Sept 65
Oct-Dec 60
That gives us an average for the year of 62.5 BCF. But, if you take just Apr to Dec you get an average of 61.7 BCF. I'm not suggesting that you should use 61.7 for your 294 day calculation but I am saying that you can't use the yearly average for a part of the year because it doesn't equate. That would mean your year end estimate of 3.055 TCF is likely to be low (and possibly substantially low) and if you use that for where you think the price of gas should be because of that low storage number then I think your gas price estimate will be off as well.
The other question would be, does it make sense that this year's year end storage will be some 28% lower than last years number given the current economic environment? My guess would be no.
Cheers.