Houston’s real-time premium to South averaged $14.34/MWh on Oct. 28 from 6 PM until 10 PM CDT

Houston drove the reversal through a much larger upside miss against its own clearance—not through South falling below expectations. Houston averaged $58.75/MWh in real time, $15.34/MWh above day-ahead. South, North and West also exceeded their clearances, but by only $2.21–$4.09/MWh. The defining Houston hour began at 7 PM CDT: $73.35/MWh real time against $46.25/MWh day-ahead. System demand averaged 64 MW below forecast during the four-hour window, offering no support for an upside system-load surprise as the explanation. The desk implication is a regional price-risk focus within a broader, smaller positive real-time surprise.

Today’s clearance does not price a repeat of Houston’s outsized lead. For Oct. 29 from 6 PM until 10 PM CDT, Houston clears just $2.67/MWh above South, while West clears $2.03/MWh above Houston. The common evening level is little changed: Hub Average clears at $42.59/MWh versus $43.15/MWh for yesterday’s matching hours. Those prices support watching the regional ordering, not assuming either another Houston-led move or a stronger broad evening market.

For Oct. 29 from 6 PM until 10 PM CDT, another Houston-over-South real-time premium averaging more than $10/MWh—together with Houston again leading the real-time-minus-day-ahead misses—would strengthen the case for recurring Houston-specific spread risk. That boundary distinguishes another sizeable separation from the modest cleared premium. Convergence toward the cleared $2.67/MWh premium, or West taking the real-time lead, would weaken the Houston-led interpretation; larger upside misses across the other hubs would instead shift attention toward a broad move.