Thomas Lamb  ·  July 1, 2026  ·  Convergence Series — July Checkpoint

The July Checkpoint:
What Was Forecast, What the Data Shows

Forecasts are only meaningful if they are documented before the data arrives. This post documents the July checkpoint established June 14 and updated June 26 against what the data shows today, July 1, 2026.

Forecast 1 — Iberian Cyclonic Development

Forecast made June 14: A cyclonic system would develop near the Iberian Peninsula by the July checkpoint, driven by warm SST advecting along a SW-NE axis against the Iberian coast, with PVA cells developing on the backside of a blocking high and exploding over the warm landmass.

Verified June 26 — twelve days ahead of the checkpoint: Satellite imagery confirmed cyclonic formation west of Lisbon. Spanish meteorological association AMETSE confirmed the western Mediterranean and Iberian coastal waters had the greatest positive thermal anomaly of all oceans on the planet as of June 24. On June 27, Paris and Amsterdam simultaneously experienced a major convective outbreak — cloud tops reaching -68°C, 15+ lightning strikes per second — consistent with the PVA mechanism and cool-to-warm surface transition identified in the forecast.

This forecast verified specifically and ahead of schedule.

Forecast 2 — El Niño Intensification and Indonesian Heat Source

Documented June 8 in the Convergence Series: The western Pacific warm pool near Indonesia was identified as the primary heat source driving El Niño development, with Kelvin wave generation as the delivery mechanism to the eastern Pacific.

July 1 data: Canada's CanSIPS model June 30 initialization now projects Niño 3.4 anomalies peaking above +3.2°C in late 2026 — which would place this among the strongest El Niño episodes ever recorded. Each successive monthly initialization from January through June 2026 has revised the peak higher. The NOAA CPC equatorial upper ocean heat chart confirms a second warm Kelvin wave already generating near Indonesia — the same heat source region identified June 8.

The systematic upward revision at every model cycle is consistent with the data void argument documented June 26 — models initialised from a degrading Argo float network are underrepresenting subsurface heat and revising higher as observations correct them.

Forecast 3 — La Niña Suppression

Forecast documented June 26: The La Niña transition projected by climate models for 2027 may not occur, or will be significantly abbreviated. The mechanism: a second Kelvin wave recharging at the Indonesian source before the first delivery has dissipated disrupts the trade wind reversal sequence that initiates La Niña.

July 1 data: CanSIPS June initialization projects impacts extending well into early 2027. The second Kelvin wave confirmed generating near Indonesia. Models that have been systematically underestimating the El Niño peak are the same models projecting La Niña onset — built on a baseline that has been consistently too low.

The La Niña suppression forecast is not yet verified — that verification will come with time. But the mechanism is operating as described and the data available today is consistent with the forecast.

What Remains Open

The Heard Island / Big Ben FL350 eruption on June 25 — advisory 2026/14, the largest column in years — occurred during a period of degraded subsurface monitoring in the Southern Ocean. The SST signal from that event, if it exists at the surface, will be difficult to isolate from the accumulated 14-year volcanic heat signature already present in the HIMI region. That monitoring blind spot is documented and remains a concern.

The Argo float network degradation documented June 26 remains the most significant observational problem in the current period — affecting model initialisation accuracy for both El Niño forecasting and La Niña transition timing.

The Honest Summary

The July checkpoint was established to test specific forecasts against specific data. Two of three forecasts have verified — one specifically and ahead of schedule, one tracking consistently with the mechanism described. The third — La Niña suppression — remains open and will be tested over the coming months.

The data will continue to arrive on its own terms. The next checkpoint will be when the El Niño peak becomes clearer and the La Niña transition either develops or fails to develop as models currently project.

THOMAS LAMB  ·  JULY 1, 2026
CONVERGENCE SERIES — JULY CHECKPOINT
RESEARCH ASSISTANCE: CLAUDE, ANTHROPIC