A few mornings out of the year ...

A few mornings out of the year ... several things line up just right such that the morning sun angles into one of my office windows and strikes the “Tuscan yellow” wall.  The result is a bright, cheerful glow that lasts just a few minutes until the sun climbs high enough that the lit spot is on the floor.  This morning was such a morning...

So what has to line up, and why does it happen only rarely?  For starters, to our east are the Wasatch Mountains.  Generally by the time the sun climbs over the mountains in the morning, the angle is already high enough that my wall won't be lit up.  The point where the sun comes up varies over the course of the year, as the seasons change.  Within the range of sunrise points there are two “notches” from the perspective of our property.  This morning the sun rose in the bottom (lowest point) of one of those notches.  The other notch (which the sun comes up through in the summer) is so far north that the patches lit up in my office on those mornings don't strike any walls.  The sun rises through the other notch in late November and mid March.  Then there's another bit that needs lining up: the patch of sun has to strike the wall where nothing is hanging.  That's about half the possible time.  Finally, it has to be a nicely clear day – even haze will diminish the brightness enough to ruin the effect.

A good start to my morning!