Timing a summit is not timing the whole route
A favourable early window may be too short for the approach, exposed section and descent. Count the time needed to reach lower ground and appropriate shelter, not only the time needed to reach the summit. A forecast icon at the trailhead does not locate storms around the entire route.
NWS lightning guidance identifies elevated areas and exposed ridges as places to leave if caught outside. It also makes clear that no outdoor position provides the protection of proper shelter. Treat a route without a timely escape as a reason to change the plan early.
A dry forecast does not rule out lightning
The model’s rain and weather-code inputs are separate signals. It can display little rainfall while still flagging a thunderstorm code; it can also miss local storm development. Neither a low rain amount nor a gap between showers proves that a summit is suitable.
Discuss the turnaround decision with the group before the exposed section. A decision made in advance is easier to follow when reaching the summit is tempting. If the forecast becomes less certain or your pace is slower than planned, the original timing assumption no longer holds.
Worked examples from the existing scorer
These complete hypothetical hours run through the same scoring functions used by the live tool. They are not observations or forecasts. The displayed effective score includes any cap.
| Example | Effective score | Verdict | Model reasons |
|---|---|---|---|
| Benign example | 100/100 | GO | No model penalties |
| Thunderstorm code | 20/100 | NO-GO | thunderstorms · NOGO cap |
| Storm and strong gusts | 0/100 | NO-GO | thunderstorms; strong gusts · NOGO cap |
Exact example inputs and units
temp and feels: °C; wind and gust: km/h; precipitation: mm/h; visibility: m; rain probability, cloud and humidity: %. Weather code is WMO; UV is an index. Pressure, where shown, is context in hPa and does not affect this scorer.
[
{
"example": "Benign example",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 10,
"gust": 15,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Thunderstorm code",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 10,
"gust": 15,
"vis": 20000,
"code": 95,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Storm and strong gusts",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 30,
"gust": 50,
"vis": 20000,
"code": 95,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
}
]Planning bands and the limits of the number
The existing model starts at 100, subtracts its condition penalties and applies critical caps. GO is 70–100, MAYBE 45–69 and NO-GO 0–44. A MAYBE cap limits the effective score to 64, and a NO-GO cap to 40. These are application suitability bands, not certified safe operating limits.
Rain branches are alternatives: matching probability, intensity and weather-code triggers do not mean adding the same rain penalty repeatedly. Separate factors can combine. A cap prevents benign temperature or dry weather from cancelling a critical flagged condition. Use the reasons beside the result to understand what changed.
The model requires complete numeric weather inputs. Missing visibility, rain probability or another required value returns Insufficient data; it is never filled with an invented favourable value. Local warnings, closures, equipment instructions and actual observations can change your decision even when the model returns GO.
Read the full hiking methodology and thresholds. The model and these examples were cross-checked on 18 October 2026. No physical field-test or safety certification is claimed.
Equipment and an alternative plan
Choose a lower route, postpone or use a destination with a practical shelter plan when storms affect the outing. Keep route information and communication available. Waterproof clothing protects against rain but does not turn a tent, ridge or overhang into lightning-safe shelter.
Questions about Thunderstorms on a hike: ridges, timing and escape plans
Will the tool warn me about every approaching storm?
No. It is a forecast tool, not a live warning or detection service.
Can I shelter beneath a lone tree?
Do not treat that as safe shelter; follow official lightning advice.
Can I wait for the rain before turning back?
No. Rain is not a reliable trigger for lightning risk.
Sources and limits
The numeric application bands come from the existing GoNoGo scorer and methodology. External guidance is linked for its stated context; it is not presented as endorsement of this model.
Live forecast data is supplied by Open-Meteo. An illustrative model output is different from a live forecast, and a forecast is different from a local observation.