The hypothetical NGL barrel, fueled by a continuing rally in the price of propane, reached its highest level in almost six months in the past week.

The barrel cracked $27 for the first time since February at Mont Belvieu, Texas, and continued to rise at Conway, Kan., as well. Mont Belvieu’s price was 42.7% higher than the price at this time in 2016 and Conway’s price was 52.4% higher.

Ranging further back, Mont Belvieu’s price was 50.3% higher than it was during the first week of August 2015, but 31.6% below the mark in August 2014 prior to the start of the commodity price slump. For those truly nostalgic, the price at this time in 2011 was $60.23 per barrel (bbl) or 122% higher (not accounting for inflation) than it was this past week. Probably best to not dwell on that.

The buoyancy in propane prices is tied to increasing exports as inventories continue to lag below five-year averages. At Mont Belvieu, propane was up 28.7% since late June. At Conway, the increase was 30.4% in that time period.

“Gulf Coast propane prices will have to stay high to curtail propane exports in August, but propane prices in Asia and Europe are starting to increase and it looks like cancellations in August will be on the light side if they do occur,” wrote En*Vantage Inc. analysts.

En*Vantage projects increased exports to Asian and European customers, which, in combination with early winter weather in the U.S., could create a propane price spike in the second half of this year. Unseasonably low temperatures do not appear likely at this point, however.

“Above-normal temperatures are favored across all of the forecast domain for the [August-September-October] outlook, as well as outlooks for [September-October-November] 2017 through [November-December-January] 2017-2018,” the National Weather Service forecast on July 20.

Still, the Mont Belvieu propane price was 70.7% above where it was at this time last year, and Conway’s price was 95.2% ahead. In the past week, propane’s margins widened by 4.72% at Mont Belvieu and 3.83% at Conway.

Isobutane’s price reached their highest levels in more than five months at both hubs. The Mont Belvieu price was 36.4% ahead of the price at this time in 2016. At Conway, the increase was 43.4%. For those who insist on yearning for the good old days, the price was 30% below what it was in 2014.

Storage of natural gas in the Lower 48 increased by 28 billion cubic feet (Bcf) in the week ended Aug. 4, the U.S. Energy Information Administration reported. The increase, below the Bloomberg consensus of 37 Bcf, is well below the five-year average increase of 54 Bcf. In 2016, storage increased by 26 Bcf. The increase resulted in a total of 3.038 Tcf. The figure is 8.3% below the 3.313 Tcf figure at the same time in 2016 and 2% above the five-year average of 2.977 Tcf.

Joseph Markman can be reached at jmarkman@hartenergy.com and @JHMarkman.