Angraecum spikes turn brown

[Yourneedfulthings]

Hi, I have a angraecum eburneum subs. Superbum plant about 2 ft. tall. It is in a clay pot with Lecca beads and looks happy to me. About 3 months ago start to grow 2 spikes that look healthy. During the last two weeks the spikes turned brown starting at the peak. The weather here has been extremely cloudy and rainy. I keep my glasshouse at 64F degrees, and have been watering this plant once per week.
Can some one tell me what may be the cause for the spikes loss and prevention?
Photos included.
Thank you.

[Keysguy]

Could be a lot of things but your recent weather is more than likely the culprit. If they get a chill, especially if it was just watered can often cause it. The other possibility is if you move it (sometimes even just a little change in orientation to the light).

I have a sesquipedale in spike now with 6 buds and we are getting a cold front coming through now with 20 mph winds and temps dipping into the high 50's tonight so I'm holding my breath.

[Yourneedfulthings]

Thank you for your replay.
Very possible, my plant is close to a window in the glasshouse and our temperatures have been dropping recently, specially at night.
I will find a place at the center where the temperatures may be more uniform.
Good luck with your. sesquipedale.