US Morning Demand Note, Tuesday, August 11, 2026
The dominant signal heading into the pre-open: a sprawling, anomalously hot pattern across all four demand-relevant zones is gaining amplitude, with the national 15-day gas-weighted CDD tracking 124 units above normal and rising sharply run-to-run.
The synoptic story is one of sustained upper-level ridging anchored over the south-central and eastern US, with no meaningful trough progression threatening the heat core through the medium range. The national gas-weighted CDD jumped from 213 to 233 across runs, a 20-unit move, signaling that models are not backing away from the heat signal; they are deepening it. The widest single-day run-to-run spread lands at August 22, where the gap reaches 4.72 units. That date sits at the edge of the reliable medium range, which is the classic location for scenario divergence: if the ridge axis holds its current position through that window, the back end of the 15-day period locks in as persistently above-normal; if the ridge sheds east or a northern stream trough undercuts the block, that August 22 day becomes the inflection where the heat load could ease. Models are not yet signaling that shed, the run-to-run direction has been additive, but that date is the one to watch for convergence or flip.
ERCOT is the anchor. At 416 CDD against a normal of 171, an anomaly of 245, Texas power burn is operating in a class by itself this summer, and crucially the run-to-run delta is zero, meaning ERCOT heat is fully priced and stable. The uncertainty is elsewhere. Northeast is where the most aggressive revision is occurring: 205 CDD against an 84 normal, anomaly of 120, with a 29-unit run-to-run jump. Algonquin and TETCO M3 are the transmission points that matter, this kind of anomaly, sustained across two weeks and still climbing, puts firm cooling load on both gas-fired generation and direct residential burn. Midwest mirrors the Northeast in character: 162 CDD against a 63 normal, anomaly of 100, with a 20-unit run-to-run gain. Chicago Citygate and MISO both have instrument chips lit, and the magnitude here, 2.5 standard deviations above normal, is not a marginal heat event. South/West sits between the certainty of ERCOT and the volatility of the Northeast: 323 CDD against 139 normal, 10-unit run-to-run gain, Transco Z4 and SoCal both active. The more modest delta here suggests the western ridging component is more stable but still running well above seasonal norms.
The overall market read is supportive across Henry Hub and regional power markets, driven by cooling burn that is simultaneously above normal in every active zone, a configuration that leaves little geographic offset to dampen aggregate demand.
What changes the picture from here: watch whether the August 22 divergence in the model suite converges toward the bullish solution over the next one to two runs, or whether a northern stream disturbance begins undercutting the ridge and pulling that day back toward the ensemble mean. A third consecutive additive run would further confirm the pattern; a flip in direction at that index would be the first signal that the heat dome is not as durable as current consensus implies. No regime label is assigned this run, treat the directional read as the operative signal until the next packet.