(Repeats Feb. 17 column. John Kemp is a Reuters market analyst. The views expressed are his own)
* Chartbook: http://tmsnrt.rs/2kwUN5L
By John Kemp
LONDON, Feb 17 (Reuters) - Warm weather has masked how much the underlying supply and demand picture for U.S. natural gas has tightened this winter thanks to lower production and strong exports.
The winter heating season of 2016/17 has so far been even milder than that of 2015/16, which was itself the warmest winter on record.
Since the start of the current season on July 1, 2016, according to the National Oceanic and Atmospheric Administration, there have been 2,454 population-weighted heating degree days - a measure of how cold the temperature was on a given day or over a period of days.
Heating demand is running 3 percent below last year, when there were 2,541 population-weighted heating degree days at this point, and 17 percent below the long-term average of 2,960.
With the exception of two short cold spells in early/mid-December and early January, the weather has been mostly warmer than normal since September.
The unusual run of mild weather has confounded forecasters, who mostly predicted this winter would be somewhat colder than the record warm winter of 2015/16.
But if temperatures have matched 2015/16, the development of the gas market could not have been more different.
Working gas stocks in underground storage have fallen much more rapidly, eliminating the big surplus left at the end of winter 2015/16.
Stocks are now 303 billion cubic feet below the level at the same point in the last heating season, having started the season 538 billion cubic feet above the previous year.
Gas stockpiles are falling week by week much more rapidly than in 2015/16 for any given level of heating demand.
Stocks are now 11 percent below the corresponding point in 2016 and just 4 percent above the five-year seasonal average.
SUPPLY AND EXPORTS
The context for the rebalancing of the gas market has been a decline in production since March 2016 after two years of strong growth in 2014 and 2015.
U.S. gas production has continued to trend lower despite a modest recovery in the rig count since the end of August 2016.
Marketed dry gas production was down by 68 billion cubic feet (3 percent) in November 2016 compared with November 2015.
In the early stages, rebalancing was aided by much stronger-than-normal consumption by power producers during the long heatwave in summer 2016.
Power producers’ consumption between July and September 2016 was 243 billion cubic feet (8 percent) higher than in the same period a year earlier.