flying once a storm has passed.

[BlueJays]

Evening!

As a very low hour PPL, I wanted to ask a few of you who probably have superior knowledge when it comes to aviation.

My question: is it safe to fly after a thunderstorm has passed, say an hour later? Would there still be severe updraft and downdrafts around?

Sorry if this is a silly question.

Sam.

[treadigraph]

Purely anecdotal: once flew as a pax in a C172 about half an hour after the passage of a very nasty storm front over Chicago. The sky was fantastically clear and smooth in its wake but I've no idea if we were lucky to encounter such pleasant conditions.

[flyme273]

In my experience, one can expect smooth air and good visibility. quite safe, say 30 mins after the front passes.

Clouds would be a clue, any updrafts/ downdrafts would have tell tale clouds of Cb, Cu nature.

flyme

[Baikonour]

It will be interesting to see what the weather buffs add to this...

Just my 2c:

I think the normal advice is to stay well clear (10 nm or so) of active thundestorms, probably more if they are strong.

So if they have passed (but are still active), and are a decent distance away and you can stay away from them (e.g. don't fly towards them) and there are no others following, you should be fine.

Of course, if they have actually dissipated, there is nothing to stay away from?

On a practical note, if there is any suspicion of embedded storms in a layer of clouds, you're probably best off staying on the ground. You want the ones which you can see (and therefore avoid!)

On a meta-level, thunderstorms are signs of extremely unstable air. The storm itself serves to release the instabilities which should mean that after the storm has passed, the air should be calmer than it was before the storm passed - like treadigraph's story shows (which ties in with my experience).

Like I said, would be interested in getting other opinions on this.

B.

[9 lives]

For my experience, flying shortly after the storm passes is fine, provided you're sure there are not others close by (if better conditions aren't coming, don't go). My personal limit is that I will not fly within the apparent diameter of an isolated storm cell away from it (If it looks 10 miles in diameter, I will not go within 10 miles of it), and only that, if I have a clear "escape" path in a different direction. I once experienced a downdraft just on the edge of my "diameter/radius" zone which took everything I could manage to escape, so being right at the edge of the storm would have been a sure collision with the ground. Do not allow yourself to be in a situation where you could be cut off from a suitable landing airport by moving weather.

Needless to say, attempting to penetrate a line of them is dumb. In the days before decent radar, I was lead through more than one squall line unwittingly while following ATC enroute clearances. After scaring myself in a C 310 I paid more attention.

There have been times I have hurriedly flown aircraft out the path of approaching storms. One turned out to be just a little less than an F1 tornado, so that worked out well!

As said, other than the actual thunderstorms, I have found that weather can be just fine in the adjacent area, as long as you pay close attention. One summer I flew a 182 Toronto to Chicago and back once or twice every week, with thunderstorms in the forecast or actual somewhere along the way nearly trip. I only had to land once (and just wait an hour for them to pass), otherwise, care and a bit of diversion here and there, and no problem.

[cjhants]

When I was training, my instructor told me that the clearest and smoothest air I would ever fly in is after a storm has passed through.

[thing]

my instructor told me that the clearest and smoothest air I would ever fly in is after a storm has passed through

Indeed, some of the best weather you will find (and for gliding too) is after the passage of a cold front.

To the OP you will be fine as long as you take advice that has been given, you will enjoy it.

[Jim59]

When I was training, my instructor told me that the clearest and smoothest air I would ever fly in is after a storm has passed through.

The smoothest air you will ever fly in is mountain wave. It is really uncanny.

[Pull what]

The smoothest air you will ever fly in is mountain wave. It is really uncanny.

Try the rotor and you might change your mind

[India Four Two]

Pull what,

That's true, but as Jim59 says, the laminar flow in a wave is uncanny. The only thing that that is moving is the altimeter hand, winding upwards.

[Penny Washers]

Ask any aeromodeller who flies competition free flight. He will almost certainly tell you that the air will be smooth and calm, but there will be gentle sink.

But watch out for anything else coming along!

[ChickenHouse]

The description "a thunderstorm just passed by" does not qualify to really judge the conditions after. On the back side of a cold front you typically have very calm weather, but to be certain you have to understand the weather. So, look at the weather charts, understand the current situation and take the whole picture. Don't be afraid, weather is quite a lot to learn, but not really difficult to understand.

[Pull what]

On the back side of a cold front you typically have very calm weather,

Totally incorrect. What you typically have is the start of the unstable air mass behind the cold front and that air mass may contain very large CB depending on the depth of the unstable layer and the chances of orographic and/or convectional lifting.

There may in fact be larger and more active cells behind the front than in the front. Beware of thinking that the model front shown in textbooks is the everyday front, it isnt.

In unstable air mass weather it is essential to use current forecasts and keep them updated. Many pilots(and instructors sending students solo) are caught out by beautiful blue skys and a million mile visibility in unstable air only to find the CB from hell between them and destination.