Precision Power Forecasting: Enverus Outperforms ISO Wind Forecasts Across ERCOT, SPP, and MISO

Summary

During the high‑wind spring season, when wind output is elevated and more volatile, accurate forecasting becomes critical for navigating market impacts. With this in mind, we reviewed the performance of the Enverus day‑ahead wind forecast across the top U.S. wind regions: ERCOT, SPP, and MISO.

The Enverus day‑ahead STPF wind generation forecast outperformed ISO forecasts across the three ISOs with the highest wind generation during the April–May 2026 period (using day‑ahead rolling forecasts published at 8 AM). The most pronounced improvements occurred during active spring weather patterns—wind ramp events, and periods of high variability—where ISO forecasts exhibited persistent bias. Table 1 summarizes total MAE and CAP_MAE for Enverus forecasts versus ISO forecasts, with Enverus outperforming the ISOs in every month analyzed.

Highlighted Ramp Events

 
The following events highlight the most impactful forecast improvements, where Enverus accurately anticipated rapid changes in wind generation that ISO forecasts missed:

ERCOT — April 17-18: Wind Collapse (26.5 → 18.5 → 25.9 → 10.8 GW)

ERCOT wind generation started very strong in the early hours of April 17, with values above 26 GW, but dropped by nearly 10 GW over 15 hours, reaching around 18.5 GW in the afternoon. However, later that same day, a strong upward trend developed over a 7-hour period, with wind generation climbing to approximately 25.9 GW by the end of the day, including a maximum single-hour ramp of 1,495 MW. On April 18, wind generation decreased once more, with a maximum single-hour ramp of -2,136 MW. The ISO forecast remained above 25 GW throughout April 17 and into the morning of April 18, missing the initial drop in wind and significantly overestimating wind generation. In contrast, Enverus more accurately tracked both the increases and declines in wind output, resulting in substantially improved performance across all days.

SPP — April 1–2: Collapse & Recovery (16 → 6 → 21 → 9.7 GW)

SPP experienced a massive swing over two days. On April 1, wind dropped from 16 GW to a low of 6.4 GW, then surged back to 21 GW by the end of the day, before declining again to 9.7 GW by midday on April 2.

The ISO forecast showed a persistent high bias, averaging 6.39 GW above actuals during this period. In contrast, Enverus maintained a much lower error, with an MAE of 2.77 GW.

This event is part of a broader pattern observed in early April, where SPP’s ISO forecast consistently exhibited strong positive bias relative to Enverus.

MISO — April 17-18: Surge then Collapse (16 → 24 → 14 GW)

MISO wind generation surged from 16 GW to nearly 24 GW, then dropped to 14 GW—a substantial swing over two days. The maximum single‑hour ramp reached -2,637 MW. 

The ISO initially over‑forecast wind by 3.44 GW on average up to the drop of wind generation then overestimated the magnitude of the decline (forecasting a drop to 10 GW, while actuals bottomed near 14 GW). Enverus tracked the actual profile much more closely, achieving a CAP_MAE nearly one‑third of the ISO’s over the full period.

Conclusion 

This consistent performance highlights the reliability of the Enverus day‑ahead wind forecast and reinforces its value to customers. Across regions, Enverus forecasts delivered stronger accuracy, particularly during high‑volatility periods, ultimately supporting improved market outcomes. 

Note: CAP_MAE represents the Mean Absolute Error (MAE) scaled by the maximum observed value (CAP) in the dataset. This scaling produces a relative error measure, ensuring that the system’s overall scale and the magnitude of values during the evaluation period do not distort the error metric.