Should I cancel my mountain biking plans over "isolated thunderstorms"?

Question

It's clear and sunny right now and the satellite doesn't show any storms in the area.

I know isolated thunderstorms means a prediction of storms hitting 10%-15% of the area. I don't want to get struck by lightning, but I don't want to be trapped at home on my day off because of a storm that may never materialize.

What are safe guidelines to working around thunderstorm forecasts?

Answer 1

Since you will be biking in the mountains, the forecast of isolated thunderstorms is not unusual as said before.

Mountains have the effect to lift air masses. This is called the orographic effect. Moist and warm air then get a chance to rise to the point where thunderstorms appear.

I have sailed all my life and now I fly a lot my light aircraft. The difference between the two activities is that, at sea, you have to take the weather that is coming. A thunderstorm in the air is much more dangerous but I can avoid it by circumnavigating it.

On a bicycle in the mountains, you can't really 'run away' from it so I think you are a bit like me on the water; You have to take what is coming.

But a thunderstorm doesn't happen without warning: The typical towering cumulus, the light wind toward the storm that then turns in gusts from the storm, the distant thunder.

Shouldn't that give you a chance to find a shelter for the short time the worst of the storm is over you?

I can't tell you what to do; you have to take the decision yourself. Sometimes I go to the airfield, look at the sky then decide fly / no-fly. Sometimes I just go home, even if I had invited a passenger. Because, as pilots say: It is better to be down here, wishing one was up there, than the opposite.

In my understanding of meteorology, isolated thunderstorms doesn't say anything about the probability of it happening, simply that they are isolated, as opposed to those found in a cold front.

As other have already said, the forecast of thunderstorm is one of the most difficult to predict. Just make sure that you have a plan B if it happens.

Good luck and have a pleasant biking trip. If the thunder surprises you, seek a low place in a valley, preferably near a building.

Answer 2

Just go, and if a thunderstorm finds you get off the bike and stand a good distance from it until it's clear.

Answer 3

Thunderstorms are usually local phenomena.  That is why it is so difficult to predict them.  Even when the conditions are perfect, sometimes they just do not form.  Sometimes when conditions seem marginal they form anyway.  Mountainous areas are at risk due to the up-slope action of hot, humid air slamming into a mountain.  These thunderstorms form quickly and tend to be extremely hazardous.  

An A.M. radio will react with sudden static if there is any lightening within miles.  If you hear that, scoot!  If you see what are known as towering cumulus clouds with significant vertical development, scoot!  If you feel a sudden stiff breeze, scoot!  If the breeze suddenly stops and then changes direction you are minutes away from being in the middle of a thunderstorm.  

If you are caught out in a thunderstorm,  seek shelter inside of a structure or cave.  Do not stand under a tree, get away from your bike and stay as low to the ground as possible.  If you suddenly feel the hairs on your body stand up, drop on your face on the ground and stretch your arms and legs out and stay that way.  That feeling often precedes a lightening strike. By grounding your entire body you can hopefully get the lightening to strike something else or pass around you without injury.  

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Answer 4

Don't cancel your plans... :-)

Answer 5

No way.  Isolated means isolated & chances are better that you won't have any rain.

If possible, take your cell phone & then try to access a moble weather radar so that you can keep on top of your local weather.

Isolated thunderstoms is a very typical summer forecast, since heat and humidity can spawn a freak t-storm any time.  If there's actually a front moving through your area, your chances of rain will depend on how fast (or slow) the front is moving.