I don't think Call Lightning works with Glyph of Warding
Glyph of Warding's Spell Glyph feature states that the spell you select:
The spell must target a single creature or an area.
Call Lightning states:
When you cast the spell, choose a point you can see under the cloud. A bolt of lightning flashes down from the cloud to that point.
So while the cloud itself fills an area, the lightning that is getting called targets a point, which is neither an area nor a creature. Spells like Hypnotic Pattern, Faerie Fire, Alarm, and Gust of Wind are examples of spells that affect an area without using a reference point.
However, Medix2 raises a worthy follow up question. It is much more common for area effect spells to have their positioning defined in relation to a point and it is conceivable that many of these spells were intended to work with Glyph of warding.
If we use this looser interpretation that allows the use of AoE spells where a point is referenced, Call Lightning still poses problems.
Glyph of warding says the area of effect must be centered on it. But the cloud is 10 feet tall by 120 feet wide and:
The spell fails if you can't see a point in the air where the storm cloud could appear (for example, if you are in a room that can't accommodate the cloud).
This means that many of the places you might cast Glyph of Warding would cause Call Lighting to fail.
If it's cast in a place that doesn't cause this problem, there's also the fact that you need to see the point where the lighting strikes. While technically the spell doesn't say the storm cloud blocks line of sight, the rules for vision and light say:
A heavily obscured area--such as darkness, opaque fog or dense foliage--blocks vision entirely.
Normally, the cloud is "100 feet directly above you" which would not interfere with seeing the location struck by lightning. But when it is right on top of and covering the only targetable area as per Glyph of Warding's requirements (to wit: "If the spell affects an area, the area is centered on [the creature that triggered the glyph]."), that means you can't see the point you want to target and therefore can't call the lighting onto it.
So, one way or another, it is difficult to see how the two spells could work together.