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🚨Record Setting SOI Drop🚨
⚠️Big Winter Storm Signal⚠️

The Southern Oscillation Index (SOI) is a key indicator of the strength and phase of the El Niño–Southern Oscillation (ENSO). Sustained strongly positive SOI values (typically 30-day average > +7 or +8) are associated with La Niña conditions, and sustained strongly negative values with El Niño.

This graph shows a very sharp collapse of the SOI from strongly positive (La Niña-like) values around +18 in mid-to-late November 2025 down to slightly positive or near-neutral values by early December 2025.

According to Grok A.I. “This is one of the fastest SOI drops on record.”

After a sudden SOI plunge of this magnitude and speed, the most common lag time to the first big Eastern U.S. winter storm or polar vortex disruption-driven cold wave is about 2–3 weeks, with a broader 10–35-day window of elevated risk.

So for the drop shown in this image (finalized ~5 Dec 2025), the highest winter storm threat in the Eastern US is roughly December 18 – January 10, peaking late December to very early January 2026. So Christmas could be extremely Wintery this year!
~Meteorologist Mark Margavage