One area of flying that has very little written about is "haze".There's a lot of stories about flight into IMC that usually center around flying into clouds, rain storms or black hole night experiences. 

However I have learned that haze can be a subtle and deadly situation. The real problem is that aviation weather reports do a very poor job of identifying and reporting on it.

Yesterday was a classic example. I was flying home from Pine Mountain Lake in Northern California to my home field of O60 (Cloverdale Airport). I got my DUATS weather briefing and everything indicated perfect flight conditions - almost no wind, sky clear, zero turbulence and no other Airmets.

I do not completely rely on the FAA weather briefings. After getting the briefing I further checked the METARS at half a dozen airports along my route. Every single airport was reporting "sky clear, winds calm, visibility unlimited". What could go wrong?

In retrospect, I probably did miss one clue in the reports. I did not look at the temp/dew point spread. It might have given me a warning for the potential for haze. 

As I took off from Pine Mountain Lake the sky really was clear with unlimited visibility. I flew westwards towards the central valley in the late afternoon. There was a thin layer of clouds around 5000 feet (so much for “sky clear”). With the late afternoon sun directly in my eyes (heading 279 degrees) the visibility was no longer "unlimited". 

In fact, the dark thin layer a thousand feet above me, combined with the haze and the glare from the sun, started to make me very aware of the potential for IMC conditions.

IMC conditions on a "perfectly clear" day - dammit! I had been looking forward to a relaxing flight home with music playing in my headset. Now I had a safety of flight condition that had to be dealt with. Music off, assess the situation.

First thing - maintain contact with ground.

Second step - how bad is it? Not too bad right now but it could get worse.

Third step - maintain contact with ground!  

Fourth step - is the there good vis behind me? Yes.

Fifth step -alter flight plan to leap frog to the nearest airport ahead in case I need to land.

Sixth step - maintain contact with ground! 

I continued on for another 20 minutes leap frogging airports at 3500 feet. Constantly re-assessing and checking behind and around for exit options in case it got worse.

This time it did not get worse. About halfway across the valley the over-head layer disappeared and I flew into spectacularly clear skies and a stunning setting sun.

This is a short video I took as conditions started to improve. You can still get an idea of the haze, however.

Haze over the California Central Valley yesterday

As the overhead layer disappeared I flew into these amazing skies:

https://youtu.be/Ja_yTSWDBpE

Even clear skies and unlimited visibility reports does not mean that haze can't present a very serious danger to flight. We seem to get this a lot here in Northern CA. Sometimes it comes in the form of smoke from wild fires. In any case, I almost died once when I lost contact with the ground in haze and I learned it is something to be very wary of.

Gary