Asia Demand Note, Sunday, 26 July 2026
*Generated 21:40 UTC | JST/AEST pre-open*
Southern Australia is carrying the session's sharpest demand signal, with Victoria's HDD15 accumulation running +21.4 above the seasonal norm and South Australia posting +24.1, both regions well through their normal winter baseline and primed to sustain elevated heating load into the trading week ahead.
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Japan
Japan remains squarely in Pacific High summer. Broad upper-level subsidence is suppressing frontal activity across the archipelago, and with no HDD15 accumulation registering in any zone, the demand question reduces entirely to cooling. Within that general framework, though, the regional picture is split in a way that matters. Tokyo's CDD15 of 147.3 trails its 157.3 seasonal normal by 10.0 degree-days, the High's western ridge appears to be favoring the central and western districts rather than the Kanto plain, where residual trough influence or a persistent sea-breeze signature may be trimming peak temperatures. Chubu, by contrast, has been building steadily: its reading of 179.2 is 10.8 above its 168.3 normal, up from a prior value of 172.9, suggesting the Pacific High is driving sustained inland heat across the central spine of Honshu. Kansai at 181.1 sits 5.9 above its 175.2 normal, although it has edged back from its prior reading of 185.9, a modest moderation but still above-average accumulation.
The Arctic Oscillation at +1.23 merits attention here. A positive AO tends to anchor polar air at high latitudes and, in some summer configurations, permits the Pacific High to extend its ridging further north over Honshu. It does not uniformly amplify the ridge across all zones, which helps explain the Kanto underperformance relative to Chubu. The El Niño signal, Nino3.4 at +2.30, squarely in moderate-to-strong territory, broadly supports Pacific High persistence over the western Pacific through the coming weeks, a structural backdrop that favors continued heat loading in the central and western corridors. The regime reads BENIGN, and that classification is accurate: no single tripwire has cleared, but the Chubu-Kansai corridor is tracking meaningfully above normal while the Kanto plain lags, a regional divergence that concentrates evening-peak aircon load away from Tokyo and toward the midland and western zones. JEPX Tokyo evening-peak pricing is historically sensitive to exactly this kind of Kanto-versus-interior split.
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Australia
The NEM's winter load picture is defined this morning by the scale and breadth of heating accumulation across the south. Victoria's HDD15 of 138.35 sits +21.4 above its 116.9 normal, a deviation that materially elevates both baseload and the morning-and-evening peak windows across the state's heavily residential demand profile. South Australia's reading of 122.85 is +24.1 above its 98.7 baseline, the largest absolute anomaly in the dataset. These are not marginal exceedances; they represent a sustained cold regime that is loading demand well above seasonal expectation in two of the NEM's most interconnected regions.
The mechanism is a strongly positive SAM at +2.79. In the southern hemisphere winter, a high-index SAM contracts the westerly belt poleward and, in a counterintuitive but documented dynamic, simultaneously opens the door for active cold-air advection from higher latitudes into the southeastern continent. Rather than acting as a shield, the poleward shift of the main westerly track allows deep southwesterly flow to channel up the Great Australian Bight and into the SA-VIC corridor with reduced blocking. The El Niño backdrop at Nino3.4 +2.30 reinforces the tendency toward drier and cooler winter conditions across southeastern Australia, though the surface thermal driver here reads primarily as a cold-surge mechanism rather than a subsidence-induced anomaly.
Queensland's HDD15 of 42.8 against a normal of 30.1, an anomaly of +12.7, adds notable depth. Cold air penetrating subtropical Queensland at this intensity reflects a meridional reach well north of the temperate zone and signals that the surge is organised at a synoptic scale rather than confined to the southern states. New South Wales at +2.1 above normal is bridging the two regimes without adding a distinct demand story of its own.
The IOD at +0.22 is weakly positive and not yet at a level where it would meaningfully tighten the subsidence-driven dry anomaly over southwestern Australia or cascade strongly onto eastern NEM states. A continued drift higher would change that calculus. For now, SA and Victoria together are the demand centres, drawing on interconnection with NSW and on wind generation capacity that is itself sensitive to the same frontal systems driving the cold anomaly.
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What to Watch
The SAM index at +2.79 is elevated but not extreme. The 00Z Monday GFS and ECMWF runs will indicate whether the poleward-contracted westerly regime is sustained into next week or beginning to break down. A backing-off toward neutral SAM would be expected to progressively narrow the VIC and SA HDD anomalies from their current +21 to +24 pace; continued positive SAM would hold or extend them.
In Japan, watch the Chubu CDD15 trajectory specifically. With three consecutive run values showing accumulation rising from 172.9 to 179.2 and the AO remaining positive, a Monday model run that continues this trend would confirm the Pacific High is loading the central Honshu corridor consistently, a meaningful input for anyone tracking area-specific demand balance ahead of the JST open.