WCSB Weeklypublic data only

Week of September 23, 2026 · published 2026-09-23

ST3/ST53 actuals: through 2026-07, pulled 2026-09-22Forward balance: model build 2026-09-22CER egress: through 2026-06 (~3-month lag)Flags: reads as of 2026-09-22

The call

Dashboard snapshot: biggest month-over-month moves

Largest absolute month-to-month changes across the 12-month forward balance (kb/d). Drill into any line on the Projected ST3 dashboard.

Top six month-over-month moves, Oct 2026-Sep 2027
MonthLineChange kb/dFrom kb/dTo kb/d
2027-01Total supply-363.14,511.14,148.0
2027-01Removals (exports)-343.14,700.34,357.2
2027-06Total supply+279.53,817.34,096.8
2027-06Removals (exports)+255.94,116.54,372.4
2027-04Total supply-230.24,265.44,035.2
2027-07Total supply+226.04,096.84,322.8

Change = this month minus prior month. Positive maintenance change means more barrels offline.

Source: Heavy Reading sd_balance.json, 12-month forward balance, built 2026-09-22

Flag reads

The six regime flags. First weekly edition: baseline established 2026-09-22, so the change column records the baseline rather than a move.

Six flags, current reads
FlagSignalReadChange vs last week
1. Enbridge Mainline apportionmentWATCHEnbridge curtailing 12.4% of nominations. Moderate stress, not pipe-full.baseline set 2026-09-22; first weekly edition
2. Alberta commercial storage utilizationNEUTRALPROVISIONAL DATA. Utilization 43.0% (26.07M bbl of 60.68M bbl provisional capacity). Comfortable buffer.baseline set 2026-09-22; first weekly edition
3. Oil sands forward maintenanceNEUTRALOct 2026 carries the only material confirmed offline barrels: Horizon residual 119 kb/d (Oct 1-12), Syncrude Coker 8-2 to ~Oct 9, Cold Lake Q4 portionbaseline set 2026-09-22; first weekly edition
4. PADD 2 refinery runs vs seasonal normNEUTRALPADD 2 runs 4,343 kb/d (4-wk avg), +307 kb/d vs seasonal norm. Demand normal.baseline set 2026-09-22; first weekly edition
5. Crude-by-rail volumes and rail arbNEUTRALRail loadings 87,977 bbl/d (May 2026), far below the December 2018 peak of 364,893 bbl/d. Relief valve idle; pipe egress covering the barrel.baseline set 2026-09-22; first weekly edition
6. Basis curve structure (M1 vs M2, WTI + basis legs)BEARISH-BASISBasis widened -1.16 $/bbl into 2026-10 (preliminary): -15.32 to -16.48. Prompt barrels clearing weaker.baseline set 2026-09-22; first weekly edition

Source: Heavy Reading flags.json, reads as of 2026-09-22

Maintenance watch

Public-confirmed offline barrels only. Seasonal-pattern items are labeled ASSUMED and never enter the math.

2026-10: Horizon (CNRL) -119 kb/d (timing as stated); Syncrude Coker 8-2 (turnaround, deferred from Q2) -49 kb/d (timing as stated); Suncor Base Plant bitumen (mine side) -15 kb/d (timing as stated); Suncor Base Plant SCO/diesel -5 kb/d (timing as stated)

2026-11: Suncor Base Plant bitumen (mine side) -15 kb/d (timing as stated); Suncor Base Plant SCO/diesel -5 kb/d (timing as stated)

2026-12: Suncor Base Plant bitumen (mine side) -15 kb/d (timing as stated); Suncor Base Plant SCO/diesel -5 kb/d (timing as stated)

2027 watch (ASSUMED, pattern-indicated): MacKay River September (strongest seasonal signal, 6 of 7 years); Firebag, MEG Christina Lake and Leismer May; Primrose April. No 2027 company turnarounds are published yet.

News and calendar

November 2026 injection trading opens October 1 (eight days). October injections are closed and post-nominations.

EIA Weekly Petroleum Status Report: US crude stocks excluding SPR 423,429 MBBL for the week of September 11, 2026 (EIA v2 API, via the desk key).

Trans Mountain ran 96.2% utilization in June 2026 with 0% apportionment; Keystone apportionment 5.0%. CER data runs on a ~3-month lag; July and August files are the next refresh.

Q3 2026 earnings begin late October: the next update to company turnaround guidance and the quarterly operator digest.

August ST3 actuals are the next data point that moves the model: they close the two-month anchor gap between July actuals and the October forecast start.

Drill into the numbers: the Projected ST3 dashboard (site/st3-dashboard.html) carries every ST3 line, 12 months of actuals plus 12 months of forecast, with project-level expanders and CSV export.

What flips this

  • Enbridge apportionment jumps past 20% on the next CER print.
    Flips it: Egress flag goes from WATCH to active constraint; basis bearish signal strengthens.
  • A 2027 turnaround gets announced for a major mining or SAGD asset.
    Flips it: Forward supply drops in that month; the flat storage path steepens into a draw.
  • August ST3 actuals print well above the July run rate.
    Flips it: Supply baseline resets higher; November/December balances build faster than +191/+166.
  • PADD 2 refinery runs fall back under seasonal norms into fall turnaround season.
    Flips it: Demand-side flag turns; removals need to absorb more or storage builds.

Methodology and sources

Physical supply/demand balance, not a differential forecast. Supply forecast at granular project leaves (AER ST53 commercial schemes for SAGD/CSS, ST3 lines for mined and conventional), then aggregated: trailing-12-month mean times a seasonal factor from the last three complete years. Mapped ST53 projects cover 76.7% of ST3 in-situ; the balance is grossed up with an explicit coverage factor.

Maintenance offline counts only public-confirmed company guidance and transcript items. Seasonal-pattern indicators are shown as assumed and never enter the math. Unknown values stay null.

Implied storage change = supply total minus maintenance offline plus diluent imports minus refinery demand minus removals (all kb/d). It is the simple physical balance, not the ST3 inventory print.

Flag signals are regime reads, not forecasts. No storage/differential relationship enters any model until point-in-time tests beat naive carry.

Sources
PublisherDatasetURLPublishedVintage / coverageRetrieved
Alberta Energy RegulatorST3 - Alberta Energy Resource Industries Monthly Statisticshttps://www.aer.ca/data-and-performance/data-and-publications/statistical-reports/st3MonthlyActuals through 2026-07 (latest file vintage 2026-08-27)2026-09-22
Alberta Energy RegulatorST53 - In-situ project datahttps://www.aer.ca/data-and-performance/data-and-publications/statistical-reports/st53MonthlyActuals through 2026-072026-09-22
Canada Energy RegulatorPipeline throughput, capacity and apportionment (open data)https://www.cer-rec.gc.ca/open/energy/throughput-capacity/Monthly, ~3-month lagJan 2018-Jun 20262026-09-22
U.S. Energy Information AdministrationWeekly Petroleum Status Report (v2 API)https://www.eia.gov/petroleum/supply/weekly/WeeklyWeek of 2026-09-112026-09-23
Heavy Reading modelsd_balance.json (12-month forward balance, 21 granular leaves)no URL on recordModel buildOct 2026-Sep 2027, built 2026-09-222026-09-22
Heavy Reading modelForward maintenance calendar (annotations/maintenance_forward.yaml)no URL on recordCompiled from company guidance and transcripts2026-10-01 to 2027-09-30, compiled 2026-09-222026-09-22
Heavy Reading modelflags.json, cycle.json, injection_brief.json, guidance_digest.jsonno URL on recordModel outputs2026-09-222026-09-22

Every number in this report traces to a row above. Any chart or table missing its own source line is flagged in place; nothing ships with an unsourced number.

Physical supply/demand balance. Not a differential forecast and not validated as one. Licensed inputs stay in the private workspace and are never committed. Built 2026-09-23.