There have been many sightings and reports of noctilucent clouds in the past few weeks. Some of these sightings have been farther south than normal. There may be a reason for you to keep a close eye out for these spectacular clouds.
Noctilucent clouds are very high clouds that only show up just after sunset or just before sunrise. I’ve never seen them before sunrise. To me evening seems like the most likely time to see these clouds.
Noctilucent clouds over Grand Traverse Bay. (photo courtesy John Robert Williams, Traverse City)
Fading sunlight gives noctilucent clouds vibrant colorings of orange, red, purple and blue. At first look, these clouds look like cirrus clouds, which are the highest clouds in the weather part of our atmosphere. Noctilucent clouds are actually higher than the main weather atmosphere, and are thought to be in the mesosphere about 50 miles high.
What would cause so many sightings of these brilliant clouds this month? Think about the weather pattern we are in. There is a ribbon of storminess embedded in the jetstream. That jetstream is suppressed south from it’s average position at this time of year. Normally I would say the jetstream is in southern or central Canada right now. The jetstream is actually over the northern U.S. and the Great Lakes now. It’s no coincidence that’s where a lot of the noctilucent clouds are being reported.
While the noctilucent clouds are 50 miles high, we can’t expect a wavy, bumpy atmosphere to not shift air movement and even moisture upward out of the troposphere, or weather atmosphere. In other words, if you are on a plane flight at cruising altitude in clear air and it’s turbulent, it’s turbulent in the stratosphere too. That air movement probably transfers into the mesosphere also.
In simple terms, we are right in the storm track. The storm track is active. Those storms help make noctilucent clouds.
So how do you see these clouds? Keep your eyes to the west just after sunset. The sky will still be brightened by sunlight. It’s usually five minutes to 30 minutes after sunset. I typically see these clouds when we’ve had a significant storm move through and skies have cleared.
In the current weather pattern and storm track, we may have a few evenings soon with these clouds. The situation might be right for noctilucent clouds this weekend.