Radar V4 Now Out Of Beta

[Paul]

Hi Snowden, I think what you're seeing is that the zoom function also zooms the air pressure in, so on the zoomed out view you're seing contour lines every 4mb, whereas on a zoomed in view that can be as little as every .5mb , so it's the same plot but with extra detail

[Snowden]

Hi Snowden, I think what you're seeing is that the zoom function also zooms the air pressure in, so on the zoomed out view you're seing contour lines every 4mb, whereas on a zoomed in view that can be as little as every .5mb , so it's the same plot but with extra detail

Em! It's seems ok now, when I zoomed in on 1034mb the range indicated was from 1004.5 to 1004.2mb. approx 30mb out? This happened a couple of times.... ?? ok many thanks Paul...

[Paul]

Now we have a bit of rain coming our way, at last there's an opportunity to show you the new scale on the radar. It still has the same level of detail as the original scale (which is still available as the default option), but it's higher contrast and has a colour background too.

Also, here's a screenshot of the new weather station overlays you get can view zoomed in, the data for these is updated every 30 minutes.

[Louby]

Oooo about time we had some rain so we can check this baby out!!

Looking really good Paul

[johnholmes]

looks good I'll go and have a play

[johnholmes]

hi Paul

quite impressive, on the screen print below with the 850mb temps on, what time is that for please? Am I right in thinking it will be whatever time the GFS is currently available for?

re the accuracy, I've tried it for several postcodes and its showing rain/showers where it should, like Leeds, Manchester etc. Just one small negative comment, the yellow, showing over me seems to be cloud only, so far anyway?

How about offering it back to the Met O, for a price of course?!

for anyone not having NW Extra then this bit even without all the other 'goodies' makes it well worth sending a cheque to Paul to join!

Edited February 21, 2008 by johnholmes

[Paul]

Hi John, re the rain showing, we just show what the meto send us in terms of data, so it could be anaprop, as it's 1km resolution it could also be that somewhere in the 1km grid it is raining, or it could be that the rain is so light it's not making it to the ground?

The GFS overlays use the latest run and the closest possible time, so currently it'll be using the 06z +3hrs data.

[johnholmes]

cheers Paul, I would suspect that it is showing ppn but at higher than ground level. Its rare for anaprop to show in a rainband in my experience.

[NL]

Great idea having gust speeds aswell, how often is this feature updated?

[Paul]

Lol good spot, the gusts have just been added about 15 minutes ago! The data from the stations, inc gusts is updated every 30 mins.

[NL]

Cheers Paul, Yep on the ball today (must be the antibiotics i'm taking at the mo..! LOL).

I was wondering if you have any plans to add visible radar too as an overlay? or will this

just clog up the system?

[Paul]

Not sure what you mean by visible radar?

[NL]

General cloud cover, i often use google earth when looking at the US

and i like to see the extent of the cloud cover then overlay IR satellite

image to show ppn.

[Paul]

Ah sorry, now I see. Adding satellite/cloud cover is something on the wish list but no eta on it at the moment I'm afraid.

[NL]

Cheers Paul, Anyway there's enough new added features to

keep me busy for a while.......!!

[kedahstorm]

Hi Paul,

My first impressions:

I've just subscribed to the rain radar service today and on first impressions am very impressed. If I can be so bold I have used the BBC and met office equivalents in the past. It seems to me that the older service or original offering by netweather gave radar images that were anemic given the colours used especially when trying to see as today areas of light patchy ppn as over the midlands. It is hardly seen or distinguisheable with background colour of land, with the land and ppn nearly the same colours.

The new V4 service gives the option to change the colour of the radar imagery to that used by both the BBC and the met office and which I have to say is perfect. This V4 setting is called TRADITIONAL. However the more contrasty NW NEW setting (all these under the scale option) seems to give the best clarity. I would have liked though the radar image colours of traditional (shades of blue) could be overlayed onto the NW NEW background, not having various shades of yellow and orange for the rainfall. If I can swear...yes say the met office, have the right colour combination with the background a brown and the imagery the same as your TRADIONAL, shades of blue, which is perfect for rainfall. Can the background of your NW NEW be done a colour different from the blue sea and green land so that blue rainfall imagery can be seen clearly on top of it, something like a pastel brown or green for land and sea or visa versa so that the blue radar imagery as in your TRADITONAL setting can be put upon it? Or an option at least?

Reading other posts I also question the reliability of the shown light ppn like for example in the Midlands area so far today. It’s Just an observation, hope you don’t mind. I’ve been out walking this a.m here in Coventry and although cloudy there wasn’t any spots of rain at all. But maybe as others have said it may well have been at higher altitudes, but we’re not so interested in that at ground level. . In reality and hindsight, the mass of these these lower ppn rates shown on the radar are, at ground level, perhaps not of a reliable enough measurement to be included in the imagery. If I do a zoom into my local patch there is a rash of these pockets of light ppn, these are for sure false positives if you like. It’s been dry, cloudy all day so far here, but the radar would have me believing otherwise. Perhaps the threshold for imagery is a little too detailed and sensitive.

Apart from these observations, I’m well pleased and think its a terric service and if things can be tweaked it can only be improved upon, just my two penneth............

Keiron

[Paul]

Hi Kieron, thanks for the feedback.

Re the colours, there is the topographical option on the traditional and original scales, which gives a grey background to the land. In terms of adding in further background options, it is something that is on the agenda, but hasn't quite made it in for V4.

In terms of the radar showing some echoes which aren't equating to rain on the ground, its the nature of the beast unfortunately. Although in a great many situations the radar is a fantastic tool, it's not infallible and is susceptible to anaprop, showing rain which doesn't make it to ground level etc.

I was speaking to the met-office about this not so long ago and this is what they had to say:

The raw reflectivity data is cleaned up before the composite is made,

which does remove clutter and anaprop, but as you rightly say, it can't

remove absolutely everything. The radars are calibrated regularly using

ground truth from rainguages but real time data from gauges is not used

on a routine basis as it is impractical to do that. A degree of expert

interpretation of the image is required (using observations and

knowledge of the characteristics of the airmass) to exclude over reading

- for example where the beams detect precipitation which is subsequently

evaporating before reaching the ground; or when the system under reads -

for example the precip is occuring below the level of the lowest beam

(drizzle from thin low stratus at the extreme reach of the radar where

there is no overlapping radar data from another site).

I hope that helps

Paul

[kedahstorm]

Thanks Paul for your informative reply which is taken on board. Keep up the good work,

Keiron

[Essan]

Great new features: excellent.....

One question, when using post code zoom with the Air Pressure overlay selected the values do not match from normal view..??

it's probably me....

cheers!!.

Just having a play myself and I'm noticing the same problem - when I use the zoom function, overlays are definitely showing up incorrectly. For example, atm it appears 850hPa temps over me are about 18.1c!!!!

Unzoomed looks to be correct and overall the features are brilliant!

[Paul]

Cheers Andy, and yes you're right there does seem to be a problem with the GFS overlays when zoomed, it's not there all the time though. We'll get that sorted!

[kold weather]

Yeah I was going to say thats the only thing I can wong with it Paul, its really a amazing radar though Im going to really njoy using it when those storms show up in the summer.

[Paul]

The bug which was causing the overlays to display incorrectly when zoomed should now be fixed, plus there is now a system in there whereby you can customise the buttons by hiding ones you may not need, these settings can be saved so the layout remains the same for your next visit as well.

As ever any feedback is much appreciated, particularly on the new option to hide buttons etc, as the jury is still out a little on them here!

[Paul]

We've been making some changes to the radar system today, first thing is, you may notice it's a touch faster as we've put in a new streamline backend on it (not that it was slow in the first place - but every little counts as they say!).

Secondly, we've made real improvements to the futureradar, if you're not using this already it's a great feature, it enables you to wind the radar forward an hour to view the predicted movement of any showers or rain bands. Just click the slider forwards (right) when you're at the latest image time to step it into the future in 15 minute intervals :lol:

[wysiwyg]

Good Stuff folks!

I noticed one tiny cosmetic thing that is different between v3 and v4 that should be fairly easy to fix if desired:

If you are using IE7 there is a feature (of IE7) that allows you to enable the mouse cursor as a 'drag hand' allowing you to scroll up and down by holding LMB and dragging up and down. I find this useful when using the laptop with widescreen and touchpad. This feature works in v3 but not in v4 atm.

TIA Wysi :lol:

[Paul]

Hi Wysi, how do you activate that option in IE7, I've not seen it before :lol: