[Xastir] Modifications for new Australian Wx Shapefiles

[Alex Carver]

The feed is going to be specific to a state.  Each of the regional NWS offices provides the data for the states or areas that they cover.  There are some active watches and warnings in southern Texas as of this writing (1741 PST) which you could look at.  The FIPS codes are listed for the affected counties under their own XML tag in the file so it's not necessary to process the textual report.  The page showing an NWS RSS feed isn't quite a true feed, it's part of a feed.  All the data in the feed is encoded as various tags.  The page happened to quote the summary field which is the human readable portion.  I believe the NWS WX server just aggregates all the state feeds into a single one.  I think it would be more advantageous to have a local server feeding the local area with the right feeds to prevent too much spillover unless it's warranted (in some cases it is).


Unfortunately there are no meso events going on right now that utilize bounding box drawings yet but if you check this page from time to time:

http://www.nws.noaa.gov/view/nationalwarnings.php?map=on

you'll see the full watch and warning coverage and be able to cherry pick the XML file.  Any meso events that utilize bounding boxes will show up on the map.  Most of the time those happen to be tornados and isolated strong cell thunderstorms in which case keep an eye on the SE US from Texas across to the Atlantic and from Nebraska south to the Gulf of Mexico.  That region will be the hot spot but typically not until spring.



----- Original Message -----
From: James Ewen <ve6srv at gmail.com>
To: Alex Carver <kf4lvz at yahoo.com>; Xastir - APRS client software discussion <xastir at lists.xastir.org>
Cc: 
Sent: Saturday, November 26, 2011 1:58 PM
Subject: Re: [Xastir] Modifications for new Australian Wx Shapefiles

On Sat, Nov 26, 2011 at 10:41 AM, Alex Carver <kf4lvz at yahoo.com> wrote:

> NOAA-NWS uses a variety of XML feeds for their different products.

Yup, got that figured out.

> Forecasts, weather warnings, and other data come in via different links that
> would have to be merged as needed.

Do we know which ones are used?

> They're very similar to what EC shows on their page.

I would agree that they probably are fairly similar.

> The entire list of feeds can be found here:  http://www.nws.noaa.gov/rss/

So is every one of these feeds is used to produce the NWS APRS alerts?

Would it be possible to see just ONE single report that would be
ingested by the NWS WX server, and the resulting output?

> Regarding the bounding boxes, I haven't looked at the XML in a while
> but I believe they do provide bounding boxes for the watch/warning areas
> in addition to FIPS county codes for times when the light up a county
> rather than a box.

I'm guessing that Canada only does an equivalent to the FIPS codes
currently. All the warning information that I have ever seen uses text
descriptions of the area of concern, and those descriptions match to
the name of a defined area.

There's a current warning in place in Ontario, for Kirkland Lake -
Englehart, and within that they call out subsections such as: Nakina -
Aroland - Pagwa, Kapuskasing - Hearst, and Little Abitibi - Kesagami
Lake.

The freezing rain warning would end up lighting up the Kirkland Lake -
Englehart shapefile, but there might be a possibility of also parsing
out the heavy snow warning for the subsections listed. However,
parsing the information out of the free text might be a bit difficult.

I would assume that the feed into the WX server has a fairly
structured format that can be parsed out by the weather server, rather
than just a free form text field that can have any text inserted by
the meteorologist of the day.

I can capture a couple hundred different samples and post them each
here asking: "Does this look right?", or if I had an idea what the
incoming feed into the WX server looked like, that I could do that
comparison and narrow the field down to likely candidates.

http://www.aprs-is.net/WX/ tells you about the details of the output
format, but not the input that is parsed to create the output.

Aha, maybe this has some clues...

http://wxsvr.aprs.net.au/limitations.html

This page lists an NWS RSS feed output that has fields highlighted...

If this is the type of input feed we need, then I can go looking for a
similar feed from EC!

-- 
James
VE6SRV