Gannon Storm May 2024
FDEWS classified elevated conditions 4 days before the largest geomagnetic storm since 2003.
NOTE: Classification, not prediction. This case study documents when FDEWS classified environmental conditions — not that we predicted the storm. Historical analysis for research purposes only.
Event Impact Summary
Industry Quote: "This storm prompted almost 5,000 simultaneous satellite maneuvers... Starlink experienced significant strains." — DCD Magazine, November 2025
FDEWS Classification Timeline
ELEVATED Risk Classification
Environmental indicators crossed ELEVATED threshold. Conditions associated with increased Forbush Decrease probability detected.
CRITICAL Risk Classification
Conditions escalated to CRITICAL tier. Higher-confidence classification based on rate-of-change acceleration.
G5 Geomagnetic Storm
Extreme geomagnetic storm. 12% Forbush Decrease. ~5,000 satellite maneuvers. Aurora visible to Florida.
Lead Time Comparison
| Method | Lead Time | Classification |
|---|---|---|
| FDEWS ELEVATED | 4 days | Environmental risk classification |
| FDEWS CRITICAL | 3 days | Higher-confidence classification |
| NOAA CME Alert | ~18-24 hours | Post-CME detection |
| Reactive Response | 0 hours | Impact in progress |
FDEWS provides earlier environmental context; official NOAA forecasts provide authoritative short-term warnings.
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What This Demonstrates
✓ What It Shows
- •Environmental classification 3-4 days before event
- •Time for proactive scenario planning
- •Tiered escalation (ELEVATED → CRITICAL)
- •Complementary to official forecasts
✗ What It Does NOT Show
- •That we predicted the specific storm or timing
- •That FDEWS replaces NOAA/ESA forecasts
- •That future events will have identical timing
- •Operational recommendations of any kind
Analysis FAQ
What was the Gannon Storm (May 2024)?
The Gannon Storm was the most severe geomagnetic storm of Solar Cycle 25, occurring May 10-13, 2024. It reached G5 (Extreme) classification — the first G5 since 2003. The event caused a 12% Forbush Decrease in cosmic ray intensity, triggered nearly 5,000 simultaneous satellite maneuvers globally, and produced aurora visible as far south as Florida.
Did FDEWS predict the Gannon Storm?
No. FDEWS does not predict solar events. Our system classified environmental conditions as ELEVATED 4 days before the event and CRITICAL 3 days before, based on proprietary analysis of publicly available data. Classification indicates elevated risk conditions, not event prediction.
What operational value did the advance classification provide?
With 3-4 days advance context, operators could have: pre-positioned satellites to minimize drag exposure, enhanced GIC monitoring on power grids, assessed polar flight route alternatives, and staffed operations centers ahead of the storm. The industry actually scrambled reactively, executing 5,000 satellite maneuvers under pressure.
How does this compare to official warnings?
NOAA issued CME arrival warnings approximately 18-24 hours before impact. FDEWS environmental classification was available 3-4 days earlier. FDEWS is intended to complement, not replace, official forecasts — providing earlier context for scenario planning while official services provide authoritative short-term warnings.
Related Research
⚠️ RISK CLASSIFICATION DISCLAIMER: FDEWS classifies environmental conditions; it does not predict specific events. Not affiliated with NOAA, ESA, or any government agency. Intended to complement, not replace, official forecasts. Historical backtest data 2010-2024. Past classification performance does not guarantee future results.