Hi all,
It has been a very long time since I've posted in here, but it has also been a very long time since I've had a problem with my Vue station.
Last year towards the end of winter (late-August as i'm in the southern hemisphere) my Vue started to record really ridiculously high wind gusts in the middle of the night in calm conditons. Like the gusts would be 0 km/h, then suddenly 80 km/h (50 mph) and then drop back to 0 km/h. The issue only occurred about 3 or 4 times on the cold mornings below about 40°F and then never happened again.
We're now heading in to late Autumn in my part of the world and the morning temperatures have started to drop below 50°F over the last week. Much to my surprise the same issue has again returned as the weather has cooled off. (The issue has not occurred at all over the summer months, with the previous occurrence during September last year)
The issue first occurred on Thursday morning, which was our first proper cold morning of the season. I had a sudden gust of 77 km/h reported in the middle of the night in amongst calm observations.
I put the issue down to the rod/shaft on the inside of the anemometer of the Vue shrinking from the colder weather and not properly making contact with the cups.
However, I noticed during the day today that the cups appeared to be sticking and not rotating during light winds. They would begin to rotate when a gust above about 12 km/h occurred, but would sit still below this strength. Which makes sense as to why my average wind speed readings have been so low lately.
During the day today, I was actually outside on the verandah in a light breeze when a sudden gust of 72 km/h was reported from the Vue. Meaning my original theory of the colder weather causing shrinking was invalid as the temperature at the time was around 74°F.
I removed the cups and washed them with a damp cloth and removed the rather large amount of spiders webs (and an actual spider) that I found in the cups and restored them back onto the ISS.
This appeared to fix the problem to some degree, the cups are now spinning from a lighter gust than before but still appear to be sticking a little during very light winds.
I thought that this may have fixed the problem.
Until this evening, my Vue reported another unusually long period of calm winds for about 2 hours before a sudden gust of 28 km/h and then more calm winds.
The problem seems to be occurring immediately after periods of "calm" conditions are reported (when light winds are actually occurring). As my Vue is located on the top of a hill, it is very rarely calm here, but the Vue has been reporting hours upon hours of calm conditions at night followed by brief extreme gusts and then further calm conditions.
Although, today it had only been "calm" for about 5 minutes when the sudden incorrect 72 km/h gust appeared.
Has anyone got any ideas as to what may be going on?
FYI: The Vue ISS is about 4 and a half years old.
