UK Storm and other bits

Today's storm has been interesting so far, but not for the reasons I was expecting. For one thing, so far, at my location, it hasn't been quite so bad as I thought it might be. We've had worse winds recently (especially the storm a couple of days after the Lincolnshire earthquake) and, so far, it's nowhere near as bad as the January 2007 storm. The main reason why it's interesting is how low the pressure is at the moment.

As my weather station got up and running I noticed that, on and off, I'd get pressure spikes and dips – these would last for one reading, rarely two, and would throw out my graphs and stats. Because of this I added a little bit of "filtering" for the graphs and other things so they'd ignore values that seemed too hight or too low.

For no specific reason I'd set the low point of the filter to 970 hPa. When I got up this morning the pressure reading was already below that and still falling. Because of this I had to make changes to the code that creates my graphs, and also to the code that adds the data to my SQL database, so that the low point is 960 hPa. The pressure is still falling and I suspect I might need to change this again so that the low point is 950 hPa (this would result in a range of 950 hPa to 1050 hPa, which would actually fit rather well with the usual range mentioned on this Met Office page).

Edit: (2008-03-10 13:00 UT) Sure enough, I've just had to modify the minimum pressure filtering again to take it down to 950 hPa because the pressure has just fallen below 960 hPa.

In other recent news (I've not really written much on this blog recently, sorry about that) I've had a couple more base station crashes. The first was on 2008-02-28 and I lost about ½ an hour's worth of data. The second was on 2008-03-08. This is the first time in quite a long time that I've had two crashes so close to each other.

Records for 2007

The records for 2007 (including min/max/average values per-month and also for the whole year) are now online.

I now have weather data for two whole calendar years.

Records for 2006

Now that I've got 1 year of data and, more to the point, now that I have data for a whole calendar year, I've extended the records section of the site to include the records for 2006. This includes min/max/average values for each month as well as the values for the whole of the year.

One year of data

It's now 1 year since I first got open3600 running on my GNU/Linux box and got it talking to be WS3600. The first data recorded was at 2005-12-27 14:16 UT, it stuttered a little for a few minutes as I modified a couple of things and then was up and running.

That same afternoon I also started work on the main site.

Some more work on the graphs

Back in July I added some graphs that showed the last 150 days' worth of data. I wrote the code to generate them rather quickly and have not touched it since.

This evening I've made some changes to how they're generated (got rid of the user of gnuplot's smooth facility and have also added some labels) and I've also added two extra graphs: the wind chill and also the impact of wind chill (the latter being the temperature minus the wind chill).

One Year

I've just realised that I've now had the weather station up and running for just over a year. I first installed it on the 17^th of December last year (and wrote about the installation in some more detail a couple of days later).

I don't quite have a year's worth of data collected yet, I didn't start collecting and keeping data until the 27^th of December (that was the same day that I started work on the main site).

Wind distribution compass

The stats page on my weather station site has always had an all-time wind distribution table. The idea is to get some sort of idea of where the wind generally blows from at my location. While it does give that information it doesn't really have that "at a glance" feel to it that you really want.

This morning I decided that this data might also work well as a "compass graph":

I think that does a very good job of giving a "at a glance" appreciation of the data. What's really interesting is that the two main peaks are west and south-south-west. Generally the prevailing winds in this part of the UK are from the south-west so you'd expect the peak to be there. I suspect that the reason for the result you see above is that there's a house to the south-west of my setup and it's creating a wind shadow.

Added a photography section

Although I've not done much in the way of weather photography I do try and snap interesting things when I see them. Because of this, and because I want to try and do more weather photography, I've added a weather photography section to my weather station website.

Giving a little back

I've added a tools section to my weather station website. The idea is to make available some of the tools I've written that make the station work (at least those that have a chance of being useful to other people — a lot of the code I've written is very specific to my setup and it wouldn't make sense to publish it).

Wind compass movie

Yet more messing about with the wind compass graph. After having it up and running for a few days I started wondering what it might look like if I created a video of the graph building up over time. This is the result:

The data is taken from 2006-11-26 and covers the first couple of hours of the day.

Yet more wind compass stuff

After adding a wind compass graph to my site's graphs, and then after improving them (with a bit of help from Tim), Tim's gone and nicked the idea for his own graphs.

Not only that, he's gone and added lots of cardioid graphs too. I'm not sure what they tell me, but they look kind of fun.

More work on wind graphs

After adding the wind compass graphs earlier today I started thinking again about the problem of averaging the wind direction. Being able to produce a useful rolling average helps with the turbulence problem I get with high wind speeds and the compass plots had a minor bug in them when the wind was moving either side of north.

So, after a little bit of searching around on the net and not coming up with anything that useful (maths really isn't my thing so I find it quite hard to make sense of most materials), I hassled Tim and he came up with a couple of useful pointers.

A little bit of hacking on rollavg later and, I think, it's all working. I can now do rolling averages on wind directions and it doesn't seem to all fall apart when the wind is coming from somewhere up north (yes Tim, the pun was too good to miss ;)).

I've now tweaked the compass plots to show both 20min and 60min rolling average values and I've also reintroduced the rolling average lines back into the old wind direction graphs.

Hopefully, this time around, it'll all work sweet.

New graphs and a new record

This morning I added a new type of graph to the graphs for today and yesterday. It's somewhat similar to the wind direction graph but, instead of showing the direction left to right, it plots it as a compass.

Edit: I've now added a compass graph for the last 7 days too.

I also had a bit of a record this morning. At 05:02 I recorded the lowest relative pressure value I've seen since I started running the station. The value was 972.4 hPa, just lower that the last record of 976.7 hPa on 2006-02-17 at 03:37.