Revision Policy for EIA Weekly Underground Natural Gas Storage Estimates
Latest Update: January 26, 2017
This report consists of the following sections:
- EIA Weekly Natural Gas Storage Report Revisions Policy - a description of how revisions to the Weekly Natural Gas Storage Report estimates may occur
- History of WNGSR Revision Policy
- Out-of-cycle Releases for Large Revisions - a description of the policy that will be implemented in the event of an out-of-cycle release
- Revisions to the Historical Database - a description of how revisions will be noted in the Historical database
Revisions may be presented for the most recent estimates of working gas in storage under a number of circumstances that occur after release of the estimates. These include:
I. A respondent revises previously submitted data (respondents are requested to submit revisions if the change is greater than 500 million cubic feet); or
II. A respondent submits late data for the week
EIA Weekly Natural Gas Storage Report Revisions Policy Revisions are disseminated in the Weekly Natural Gas Storage Report (WNGSR) according to the established schedule and shall occur when the net reported changes to working gas levels are at least 4 billion cubic feet (Bcf) at either a regional level or for the Lower 48 states. If a revision is made, changes to all regions shall be recorded. Consequently, although all respondents' changes shall be entered into EIA's database for analytic purposes, the changes shall only lead to a published revision when the respondent-reported changes are at least 4 Bcf. Consistent with the established revisions policy, estimated measures of sampling variability shall be updated using the data currently available at the time of the disseminated revision. Reported revisions that reach or exceed 10 Bcf for the current or prior week at the regional level or for the Lower 48 states, and that are not the result of errors that accumulated in prior weekly periods, will be published in an out-of-cycle release of the WNGSR as described below.
History of WNGSR Revision Policy The policy was announced in a November 2002 Federal Register notice. Subsequently, EIA in early 2005 solicited via a Federal Register notice (70 FR 1426-28) public comment on possible modifications to the existing revision policy to allow certain releases on an unscheduled basis. The response to that solicitation resulted in the following policy that was announced in a Federal Register notice published on April 26, 2005. In 2014, EIA solicited updates to that revision policy to lower the threshold of reportable revisions from 7 Bcf to 4 Bcf and update the unscheduled revision policy to mandate that the data changes or corrections be at least 10 Bcf for the current or prior week and not a result of cumulative errors that have accrued over periods greater than the last two weeks. Comments for these modifications were received via a Federal Register notice (FR Vol. 67 No. 218 Doc. 2014–23751) and the following policy was announced in a Federal Register notice published on October 7, 2014. This most recent change to the revision policy is being implemented in November 2015 along with new regions for the WNGSR.
Out-of-cycle Releases for Large Revisions The unscheduled release of revisions to WNGSR data shall occur when the data changes or corrections are at least 10 Bcf for the current or prior week. Revisions shall be disseminated on a federal workday at 2:00 p.m. (Eastern Time) following notice of the pending release to the public between 1:00 p.m. and 1:10 p.m. (Eastern Time). If a revision is made, changes to all affected regions shall be recorded in the 2:00 p.m. release. Public notification of the unscheduled release will occur in a number of ways, including a website notice of the impending release of revised data that will replace the current Weekly Natural Gas Storage Report, email notification to selected media, and an email notice to all users of the WNGSR who have signed onto a free distribution service. There are two special circumstances related to handling certain data changes in the WNGSR. First, this unscheduled release policy will not apply to data changes resulting from changes in the estimation methodology or parameters because those changes will be announced in advance. Second, reclassification of gas (between working gas and base gas inventories), regardless of size, will be reported only in regularly-scheduled releases of the WNGSR. A copy of the Federal Resister notice (FR Vol. 67 No.218 Doc.2014-2375) detailing the updated policy for unscheduled revisions is available at: http://www.gpo.gov/fdsys/pkg/FR-2014-10-07/pdf/2014-23751.pdf.
Revisions to the Historical Database The historical database is updated weekly and contains the most current set of estimates available. Although the typical update is limited to insertion of an additional week of storage estimates, prior estimates also may be revised. Also consistent with the current established policy, the historical database of estimated measures of sampling variability will be updated weekly and will contain the most current set of estimates available. These historical estimated measures of sampling variability may be revised when the historical working gas levels are revised.
Beginning in November 2015, EIA will release a historical file of revisions and reclassifications. Each time a revision or reclassification occurs, the file will be updated with the original estimate prior to the revision or reclassification and the accompanying note that was published in the WNGSR.