Severe weather warning regions

[robbie MacIntosh]

Hi collective.

I'm currently building an app to make it easier for people to get access to things like weather and other alerts based upon their postcodes.

I've been searching the data point sources and can't seem to find anything that would allow me to map a postcode (or outer postcode) to a severe weather region.

I had a similar situation with the environment agency but they had polygon's that were downloadable.

Does anyone know if either the polygons exist and I can then use python to find the postcodes inside etc or if there is a downloadable lookup where I can take each postcode and apply it to a region. that way my users can subscribe to a region (via their postcode) and get the relevant warnings issues.

thanks in advance.

ps, I did see a topic this from years ago, but nothing recent so thought a new topic may be more relevant.

[Chris Wilson]

https://postcodes.io/

free to use, lat and long come back on the response object

response.result.latitude

response.result.longitude

reverse lookup..

api/postcodes.io/postcodes?lon=[your longitude]&lat=[your latitude]

[robbie MacIntosh]

thanks for this, I'll check it out, they might not be happy with my 2.4m checks ;-)

[Andy Barnard]

Hi,

I think I misunderstood the original request as I thought it was about location data for severe weather warnings, not geo-locating postcodes.

I've used this dataset before to geo-locate postcode data for other purposes:   https://geoportal.statistics.gov.uk/datasets/60484ad9611249b59f3644e92f37476d/about

Its downloadable so the lookup is offline.  Its less geographically accurate in lower population densities.  Its a snapshot from a couple of years ago.  YMMV!

Andy

---

From: metoffice...@googlegroups.com <metoffice...@googlegroups.com> on behalf of robbie MacIntosh <robbie.m...@marbledropper.com>
Sent: 27 February 2024 09:18
To: Met Office DataPoint <metoffice...@googlegroups.com>
Subject: Re: Severe weather warning regions

 

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[Alan]

Morning

If you go to the National Severe Weather Warning Service from the Met Office at:

https://metoffice.github.io/nswws-public-api

You will find an API and documentation which describe the GeoJson responses that include the polygons you are looking for.

Alan

[Robbie MacIntosh]

Thanks Alan, I’ll have a look there too.

 

 

 

Robbie MacIntosh

Marbledropper Limited

(+44) 7717 878 002

 

 

 

From: metoffice...@googlegroups.com <metoffice...@googlegroups.com> on behalf of Alan <alan....@gmail.com>
Date: Tuesday, 27 February 2024 at 11:09
To: Met Office DataPoint <metoffice...@googlegroups.com>
Subject: Re: Severe weather warning regions

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[Connor Gurney]

Robbie,

Given that you seem to be aiming to identify NSWWS warnings in force for a particular postcode, you need two things here: the polygons for the warning areas, and the precise locations of the postcodes. You can then use something like the ray casting algorithm to ascertain whether the coordinates of the postcode fall within the polygon of the warning area for each warning.

The polygons for the warning areas are, as Alan explained, always provided within the response from the NSWWS Public API, which I assume is how you're fetching the warnings. They're accessible in the "geometry" element of each individual warning and adhere to the MultiPolygon type within the GeoJSON specification (which is covered at length in RFC 7946 if you're not bored enough already!).

As for postcodes, this is data that you're likely to have to pay for — especially with 2.4 million lookups! The authoritative dataset for this is Ordnance Survey's Code-Point product which maps every single UK postcode to its coordinates. If my memory serves, one license costs £525, but it might have gone up like everything else. 😅

This has become something of an area of expertise (albeit not through choice!) so feel free to reply if you've any more questions and I'll do my best to help.

Best,



Connor Gurney

Chief Executive Officer

+44 (0) 7713 414484

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Gurste Ltd (trading as Gurste) is registered as a limited company in England and Wales under company number 15458446 at Wellington House, Pollard Street East, Manchester, M40 7FS.

[Robbie MacIntosh]

Thanks Connor,

 

Much appreciated.

 

Robbie

 

 

 

Robbie MacIntosh

Marbledropper Limited

(+44) 7717 878 002

 

 

 

From: 'Connor Gurney' via Met Office DataPoint <metoffice...@googlegroups.com>
Date: Thursday, 29 February 2024 at 15:32
To: Met Office DataPoint <metoffice...@googlegroups.com>
Subject: Re: Severe weather warning regions

Robbie,

 

Given that you seem to be aiming to identify NSWWS warnings in force for a particular postcode, you need two things here: the polygons for the warning areas, and the precise locations of the postcodes. You can then use something like the ray casting algorithm to ascertain whether the coordinates of the postcode fall within the polygon of the warning area for each warning.

 

The polygons for the warning areas are, as Alan explained, always provided within the response from the NSWWS Public API, which I assume is how you're fetching the warnings. They're accessible in the "geometry" element of each individual warning and adhere to the MultiPolygon type within the GeoJSON specification (which is covered at length in RFC 7946 if you're not bored enough already!).

 

As for postcodes, this is data that you're likely to have to pay for — especially with 2.4 million lookups! The authoritative dataset for this is Ordnance Survey's Code-Point product which maps every single UK postcode to its coordinates. If my memory serves, one license costs £525, but it might have gone up like everything else. 😅

 

This has become something of an area of expertise (albeit not through choice!) so feel free to reply if you've any more questions and I'll do my best to help.

 

Best,



Connor Gurney

Chief Executive Officer

 

+44 (0) 7713 414484

 

Sign up for early access

 

Gurste Ltd (trading as Gurste) is registered as a limited company in England and Wales under company number 15458446 at Wellington House, Pollard Street East, Manchester, M40 7FS.

 

On Tuesday 27 February 2024 at 12:07:09 UTC robbie.m...@marbledropper.com wrote:

Thanks Alan, I’ll have a look there too.

 

 

 

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[robbie MacIntosh]

just wanted to look back on this....

having looked at this, it was not the data I was hoping, it is the 'map' of the weather pattern across the UK, so a weather warning from Cornwall to Perth has the same polygon at that is the weather front.

what I was looking for was the regional polygons that they use, ie if a user is sitting at a point in the UK, then we can work out their regional location based upon that...

this then led me to getting the email updates and found another little issue, the email subscription has a list of counties... and the email has a slightly different naming convention..

eg...

•   All pages in:Weather Warnings 
  •   Orkney & Shetland 
  •   Highlands & Eilean Siar 
  •   Grampian 
  •   Strathclyde 
  •   Central, Tayside & Fife 
  •   SW Scotland, Lothian Borders 
  •   Northern Ireland 
  •   Wales 
  •   North West England 
  •   North East England 
  •   Yorkshire & Humber 
  •   West Midlands 
  •   East Midlands 
  •   East of England 
  •   South West England 
  •   London & South East England 

that's the list you can subscribe to...

then when you get an email you get headings like...

Yellow warning for Central, Tayside & Fife - which is great...

but then you get an alert for....

Yellow warning for Dumfries, Galloway, Lothian & Borders - which doesn't match exactly...

which is not an exact match, so although this can be resolved as I think it's only 1 or 2 regions that don't match.

and sadly I'm back at a similar point in trying to find the geographic boundary or list of postcodes that are used when a user wants to be informed about weather in their area.

[Connor Gurney]

Robbie,

To clarify, are you wanting to identify their location before warnings are issued or at the time of their issue? 

If at the time, you can use the polygon data from the warning and check which postcodes fall within it, but this is likely to be computationally expensive.

However, if you want to do it in advance, your best bet is likely to be to contact the Met Office’s data provisioning team, as I would imagine they have the polygon data.

I’m sorry that I can’t be more helpful, but do let us know how you get on.

Best,

Con

Sent from my iPhone

On 11 Apr 2024, at 13:39, robbie MacIntosh <robbie.m...@marbledropper.com> wrote:



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[robbie MacIntosh]

Hi Connor,

yes it's the advanced polygon or list of postcodes that I'm looking for as our users can then use their GPS to join this and other relevant groups based upon their location.

And yes the polygon of the weather impact is useful it's not what we were looking for at this time, although that may change to make the impact more specific.

I've dropped a contact us to the team on the feedback page to see if they have the 'region' boundaries in any format, I've  also highlighted the disconnect in terms of the naming conventions that make a little more challenging.

[robbie MacIntosh]

and pretty sure I'm a human....

so I went the other route and raised it via website enquiry AND contact us...

hopefully one will be positive.

On Thursday, April 11, 2024 at 1:50:24 PM UTC+1 c...@gurste.com wrote:

[Connor Gurney]

Makes sense, Robbie!

To be honest, the API is poorly documented at the moment, so I might draft something and see if I can raise some interest at the Met Office — watch this space. ✨

Sent from my iPhone

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