Site Blog and Weather Station news/updates

Weather station maintenance / minor upgrade

After almost five years of constant weathering, the radiation shield for the thermo/hygro sensor was showing serious signs of decay. To remedy this, the base and roof have both been replaced; the body itself seems to be in reasonable enough condition to survive another few winters at least, but has been thoroughly cleaned to maintain its reflective gloss. The rain gauge has also been cleaned out, having built up a considerable layer of moss and dead insects within its internals.

In addition to this maintenance, I have replaced the rain gauge collection funnel with another of a larger diameter (25 cm, up from 19.5 cm), thus increasing the gauge's resolution from approx. 0.30 mm to 0.18 mm. The consequences of this change are:

  • A little under 0.2 mm of rain needs to fall to trigger a 'rain day', rather than 0.3 mm
  • Rain rate is more accurate during heavy rain/showers
  • Brief showers are more likely to be detected
  • Quicker response in reporting rain after it starts to fall.

So, good news all around. However, the sensors themselves are showing signs of wear and will probably need replacing next year. Or perhaps I'll replace the entire weather station with a newer and better model. Either way, more weather hardware upgrades to come in 2015 (along with the website upgrades)!

Before:

After:

A full photo album has now been published, but I still need to touch-up the old paintwork before declaring the project complete.

Posted: 30th Mar 2014

Source code release and latest website development plans

All source code is now available on GitHub, organised by site version.
The latest website upgrade is underway (site v.4), and the beginnings of the new code base are available there, too.

This next iteration of nw3weather will initially involve entirely back-end upgrades, of the data model and major refactoring of the source code. Following the completion of this upgrade in approx. mid-2014, further features will be worked on and test releases to the live site will be performed before a full live release in 2015, probably.
I have now moved to using PivotalTracker as a project management tool for nw3weather development. This enables easy management of bugs, features and chores throughout the development process, and this is the best place for nw3weather users to follow the latest goings on.

P.S. I will be performing some minor weather station maintenance and upgrades in the spring; detailed information will be posted when this is ready to be undertaken.

Posted: 4th Jan 2014

Site update - version 3 released

Site v3 has now officially launched!
Some of the biggest changes include:

  • Graphs and charts - now prettier and available for many more data types and periods (also, unit-switchable)
  • Manual observations - These are now better-incorporated into the site, making it easier to track snowfall and sunshine hours etc.
  • Site design - I've settled on a fixed-width layout for now, as it is much easier to get things positioned properly
  • Data control - almost all processing of images and raw data is now done on the server (rather than local PC); this makes it much easier to correct glitches, add features, and reduce inconsistencies and errors
  • Rankings - It's now possible to view ranked data in a number of places
  • Javascript - This is increasingly being used to improve usability, but I'm aware that a lot more needs to be done in this area.

On account of these fairly significant changes, the loss of a few of the site v2 features, and given that I no longer have any interest in supporting old (pre-8) versions of Internet Explorer, you may well decide to stick with the old site, version 2.
Thus, I will be keeping site v2 going for a while yet, at this link.

As ever, I will continue to work on improving the site, and welcome suggestions for the next site upgrade. Additionally, feel free to contact me if you think I've unreasonably removed a feature during the upgrade, or you find a bug. Thanks.

Finally, be aware that site v3 uses new values for the long-term-average rainfall to reflect recent analysis (see post from 7th Jan 2012 below and the updated xls). Updated values are to be found on the new climate page. The rest of the climate averages will be updated for the start of 2014 to reflect the newly available 1981-2010 standard averaging period.

I really hope you all like the changes I've made, and thank you for visiting nw3weather.

nw3weather site v3 banner

Posted: 22nd May 2013

Site update - version 3 released this month

Upgrades to the site are now complete, and site v3 is almost ready to launch. I'll be doing some testing and final refinements this month, ready for a release on or close to 22nd May. The changes are fairly minor from a user-perspective, and for the most part I've merely been adding new features.

Posted: 6th May 2013

Site update - version 3 in development, now available for preview (beta?)

I've been working on this on and off since June, but I've come to the realisation that I'm not going to be able to finish it to a level that's acceptable for a full release this year. However, I'm releasing site v.3 as a 'beta' (incomplete, potentially buggy, but usable). I'll continue to upgrade, fix, and add new features, so please note that content may change or dissappear from it at any time. Any feature suggestions, reports of problems, or general feedback are all welcome - please use the contact page. Many pages are unchanged but all have adopted the new look, and server-side graphs has been implemented.

Posted: 30th Sep 2012

Weather Station Problems - data downtime

In the last few months the weather station console, which receives data from the sensors wirelessly, has been dropping the link to these sensors with increasing frequency. Yesterday's downtime was the longest so far and unusually affected all sensors; mostly it is just the wind sensor that drops out. A manual reset was required to solve the problem. I am beginning to wonder whether the console may be failing, so further periods of downtime seem likely, and I may have to replace it, at surprisingly considerable cost; in fact I may well buy a complete new weather station in the summer should problems persist. I have owned and operated the station for almost three years.

As a side note, all data that gets lost in these periods of downtime is usually reconstructed using data from other weather stations in London, principally the nearest - at Whitestone Pond. Periods of downtime are easily discerned from the graphs, which show either 'flatline' (wind data) or clear evidence of interpolation (temp, hum data). Yesterday's (15z-23z) is a prime example:

graph NB: The graph page can be used to check for recent downtime; old graphs are archived here.
Posted: 8th Jan 2012

Rainfall Figures - adjustments to correct possible under-reading

Early in 2011 I suspected that the electronic rain gauge may be under-reading, so I decided to set up a manual rain gauge that could be used to check the performance of the automatic one. Suspicion arose due to conflicting figures with an "official" Met Office-standard weather station at Whitestone Pond, about 2km away. On completion of the set-up of a traditional rain gauge in September 2011, manual rainfall data collection began, and the figures compared to my automatically-recorded rainfall. As of December 2011, early results from comparing the data from the two rain gauges suggested a correction of +5% was needed on the automatic one, which was implemented for the start of 2012. Further data will be collected in 2012, with a final correction to be decided on for the start of 2013.

In January 2012, I made a full comparison of rainfall data collected here versus figures from the Whitestone Pond station, as well as a few others around London. The results are available as a .gif and as the original .xls file. Averaged over the available timeframe, closest agreement was with the MetO station at RAF Northolt, 15km away but at a similar elevation. After adjusting for the +5% correction suggested by manual data collection, the figures recorded here are still some 15% lower than those from Whitestone Pond. However, the agreement of my figures with Northolt's suggest that this is possibly down to elevation difference (55m at NW3weather versus 140m at WS Pond), since this station is at the bottom of Hampstead Heath whereas WS Pond sits atop the highest point in London.
Regardless of the cause, the essential conclusion is that the long-term rainfall averages I derived from the WS Pond station are incorrect, and need to be adjusted downwards. I plan to implement these changes for the start of 2013 so that I have time to adjust other figures (such as temperature) as well, should it be necessary.

auto gauge manual gauge
Posted: 7th Jan 2012

Site News - two new pages, more in development

Welcome to the NW3weather blog! This is the first of two new pages for the New Year. The second is a logical addition to the historical reports, annual weather summaries, to compete the set which started with only daily and monthly reports. A summary section has been added to the monthly weather summaries, though this is not yet finalised. Furthermore, the daily weather reports page is in need of a complete overhaul to bring it in line with the style of the others, but I've put that on hold for now.
Development of more pages with historical data and records is underway, but the next update will not come before July 2012, when I will have time to continue with site development.

Posted: 7th Jan 2012

Updates: The new superscript remains in place in the sidebar for three days after the last blog post. Hover over it to get the date of last posting.