Android Skew-t app

[kiwiindenver]

Hi All,

As a recently licensed pilot I decided it would be a good idea to learn more about soaring weather prediction, specifically the workings of a Skew-t graph.

I combined that with learning more about developing Apps for Android, so yesterday I published by first Android App.

https://play.google.com/store/apps/details?id=com.ajw.skewt

I hope many of you find this useful.

I welcome your suggestions for improvements. As I said, this is new to me.

Enjoy.

Alan

[Tony]

Is this based on RAOBs only? Any way to include forecast soundings for those of us who dont live near a.weather balloon?

I like the presentation at first glance

[kiwiindenver]

On Thursday, March 27, 2014 11:13:37 AM UTC-6, Tony wrote:
> Is this based on RAOBs only? Any way to include forecast soundings for those of us who dont live near a.weather balloon?
>

I'm happy to make changes that are needed.

The app uses the default settings from http://rucsoundings.noaa.gov/, setting the time and the airport code. This means the default source is Op40.

[Tony]

Oh OK that's alright.

[JS]

Cool.
It currently is not displaying numbers in the airport ID.
Perhaps a "pro" version could include the ability to input Lat/Lon with a couple of user-created shortcuts?
Nice job,
Jim

[kiwiindenver]

My validation code is stripping the number. I will add some Lat/Long validation so either will work.

[kiwiindenver]

I have just published a new version that has initial support for Lat/Long. I will improve this later. This version is a quick fix to get people up and running and hence help get more feedback.

For now, enter a comma separated pair of decimal lat/long using negative for South and West. This is the same way you enter lat/long into the NOAA site.

PS. It may take a few hours to push this version through the Google servers.

[Tony]

Sweet. Being able to save and name "favorite" locations would be great.

It seems like there is some round up on the ground elevation? When I put KHUT, Hutchinson, KS, in it has the base altitude at 2000 ft when it should be more like 1600.

Also looks like the default time is 8 am to 7 pm. That's OK but I think by this time of the day the Op40 should be able to forecast to tomorrow morning which would be nice. Perhaps you could have it start at 8 am of the current day and go out as far as the forecast is available?

Next of course will be to include the other models...

I really like this presentation and thinking will come in really handy.

[kiwiindenver]

Thanks for that feedback. I'll take a look at those problems.

Your right about the time, I set those limits thinking it would easily cover most soaring needs. I'll do some more investigation to see what data is available for download.

How many favourites do you think you would want? How many would you use regularly? How many would you use once in a blue moon?

How important are the other models? Would this be a set & forget item or something you change regularly?

[Dan Marotta]

I tried to use the identifier for Moriarty, NM, K0E0, and get the error,
[Failed to load KE!]. Does the program not accept numerals (zero) in the
identifier? Still working on the conversion to decimal Lat/Lon...


"kiwiindenver" <alan.w...@gmail.com> wrote in message
news:28d10f96-ac8e-4cff...@googlegroups.com...

[Dan Marotta]

Made the conversion, looks nice. Now I need to review how to use the Skew-T
chart.


"Dan Marotta" <dcma...@earthlink.net> wrote in message
news:lh43l5$b54$1...@dont-email.me...

[kiwiindenver]

Yes I currently strip numerals. I will fix that for you.

[son_of_flubber]

This is a very worthwhile effort. I get a very readable graph if I turn my Nexus 7 horizontally, set 'low altitude display' and zoom in 2X. That makes the fonts big enough to read easily and displays the altitude of interest (up to about 10K for me). And it allows me to see the wind speed graph at the same time.

The 'time warp' slider is informative and helps to get a feel for how conditions change through the day.

Here are some not necessarily good ideas off the top of my head:

It might be useful to have the option to set surface temperature automatically based on forecast.

For eastern pilots,it might be useful to have the option to display the data to top of 10K, but only if you also had the option to choose a larger font.

It might be useful to display a user-defined vertical line in the wind graph.

It might be useful to display a small circular surface wind direction indicator.

It might not be useful, but I'm curious what one would see if you implemented a 'geographic position' slider, to for example incrementally change the ground position upwind while keeping time constant.

Also somewhat outside the scope of your project, I like to look at how cloud cover is predicted to change through the day.

[herbk...@gmail.com]

flub, there is already a site that does all your 'useful' functions splendidly:
http://www-frd.fsl.noaa.gov/mab/soundings/java/

You can load it on your Nexus through any browser. I think the Android app is just fine in displaying a limited subset of that data.
Many thanks Alan, very nice app you put together.

[kiwiindenver]

>
> http://www-frd.fsl.noaa.gov/mab/soundings/java/
>
>
>
> You can load it on your Nexus through any browser. I think the Android app is just fine in displaying a limited subset of that data.
>
> Many thanks Alan, very nice app you put together.

FYI. One reason I wrote this app is my Nexus-7 doesn't have a supported java plugin so you can't load the noaa site.

I do agree that I want to keep this app simple but functional.

[kiwiindenver]

Thanks for all the testing and feedback everybody has given me.

I've just posted a new fix.
- The ground level reading in now included in the graph
- Airport ID's with numbers are allowed.

I'm working on adding different data sources which will allow global use.

What do you think about adding support for waypoint files? You could then use waypoint names as an alternative to Airport ID.

[2KA]

I personally would love to see easy support for other models. For me, it wouldn't be a "set and forget" thing. I regularly consult different models to get an idea of consistency across them.

Nice job, by the way!

Lynn Alley
"2KA"

[kiwiindenver]

This might be making work for myself :-).

Would it be useful to overlay two (or more) models onto the same graph? If I did that cleanly would it now be a set & forget setting?

[Tony]

I think that would be a cool option

[soar...@gmail.com]

Alan,
Thanks a lot. It works like charm for where I am. I especially like the moving graphics.
Is there a way we can get some forecasting, like one or two days? Right now I can only get the current day.


On Thursday, March 27, 2014 9:25:32 AM UTC-7, kiwiindenver wrote:
> Hi All,
> <Snip, Snip>

>
> As a recently licensed pilot I decided it would be a good idea to learn more about soaring weather prediction, specifically the workings of a Skew-t graph.
>
>
>

[kiwiindenver]

On Friday, March 28, 2014 11:44:52 PM UTC-6, soar...@gmail.com wrote:
> Alan,
>
> Thanks a lot. It works like charm for where I am. I especially like the moving graphics.
>
> Is there a way we can get some forecasting, like one or two days? Right now I can only get the current day.
>

I have different data sources mostly working, it just needs a bit more testing.

After that I want to add
* Named favourites (or something similar)
* Underlaying secondary model
* Extended range forecasting

Alan

[JS]

Alan I think you've already hit the target.
For me this app will be used as an extension of an under-rated weather site:
"lookoutthewindow.com"
Read the label on your browser's tab for instructions.
Any forecasting for days ahead can be viewed at home on something with a decent sized screen or screens.
Jim

[kiwiindenver]

I have just uploaded a version that allows selection of different data source weather models.

I have checked as much as I understand, but I'm a but out of my depth and would appreciate help to make it as useful as possible.

[kiwiindenver]

On Monday, March 31, 2014 9:09:10 PM UTC-6, kiwiindenver wrote:
> I have just uploaded a version that allows selection of different data source weather models.
>
>
>
> I have checked as much as I understand, but I'm a but out of my depth and would appreciate help to make it as useful as possible.

Use of different weather models appears to be stable now. Google statistics show I have 64 installs in USA and 55 for the rest of the world. Thanks to everybody. I have just uploaded a new version for you to continue to enjoy.

The new version has a number of small changes as a result of feedback sent to me. The most significant change is the addition of a favourites list. This will allow you to quickly switch between different locations and/or different weather models.

Alan

[son_of_flubber]

On Thursday, April 10, 2014 3:05:24 PM UTC-4, kiwiindenver wrote:
>
> > I have just uploaded a version

Hey Alan. I just wanted to say thanks and that this app came along at just the right time for me. I'd worked through the theory of skew-t before, but I've been too lazy to look at the current skew-T on the web very often. So not enough practice time.

I have your Skew-T app running on an otherwise only occasionally useful Nexus-7 that is sitting on my window sill. I've been making it a habit to pick it up several times through the day, and look at the sky and the skew-T and think about what is happening and why. On some days that prompts me to look for other weather data on the web and try to bring things into focus. I'm hoping to get to the point that I can look at the sky and visualize the Skew-t and have a sense of a 'typical day' at a particular time of year progresses.

One problem that I have is that the surface temp indicator seems to sometimes track the forecast with the time slider, and sometimes it stays fixed/manual. It seems that tapping, sometimes toggles the mode, but not always. Is there a bug or is my tap and touchscreen funky?

Thanks again.

[kiwiindenver]

Glad its working for you. It sounds like I'm at a similar stage of my flying career, I wrote this App to learn more about the science, math and data behind Skew-t.

I'm not confident I understand your description, can you send me a screen snap (or two) and a description so I can fix any bug that might be present. My email is in the new "Quick start guide" info.

Alan

[kiwiindenver]

For your enjoyment,

The newest version (uploaded 5 mins ago), can now show future data, not just today's data. Obviously this is only if the weather model supplies the needed data.

Also I have added a "Here" mode that uses your devices GPS to seed the lat/long.

Next I want to add support for waypoint files.

Any other requests or feedback welcomed.

Alan

[JS]

Alan, you must be having fun with this!
Thanks,
Jim

[kiwiindenver]

Yip!!!

I've talked to a number of people from all over the world and everybody has helped to make this a better app for soaring. I have also learnt LOTS AND LOTS about Skew-t graphs and data.

Unfortunately I think my ride is coming to an end as it already does most things people have asked for.

Enjoy
Alan

[drk...@gmail.com]

On Thursday, March 27, 2014 at 11:25:32 AM UTC-5, kiwiindenver wrote:
> Hi All,

>
> As a recently licensed pilot I decided it would be a good idea to learn more about soaring weather prediction, specifically the workings of a Skew-t graph.
>

> I combined that with learning more about developing Apps for Android, so yesterday I published by first Android App.

>
> https://play.google.com/store/apps/details?id=com.ajw.skewt
>
> I hope many of you find this useful.
>
> I welcome your suggestions for improvements. As I said, this is new to me.
>
> Enjoy.
>
> Alan

Alan, I just came across this app and am trying to learn how to use it. I get the temp and dewpoint lines. But what does the green line intersecting a gray line with the dark marker at the intersection mean? And what does moving the spot marker off of the temp line accomplish? It defines a grayed area in sort of a triangle but I haven't figured out what it's telling me.

Ray
Commercial/instrument single-engine land

[son_of_flubber]

On Wednesday, January 24, 2018 at 1:51:47 PM UTC-7, drk...@gmail.com wrote:
> But what does the green line intersecting a gray line with the dark marker at the intersection mean?

The green line is of great interest to glider pilots because it represents a bubble of air warmed by the sun hitting the ground. Once the bubble breaks away from the surface it starts to cool. The green line represents the temperature of the air as it rises. As long as the green line in to the right of the red line, the bubble will continue to rise. The red line of course represents the temperature of the ambient air as you go up in altitude. Where the green line crosses the red line the bubble is the same temperature as the ambient air at that altitude. So buoyancy is neutral. But the rising bubble has mass, so it has momentum and that carries it above the altitude of the crossing point.

So the rising bubble of air is followed by another rising bubble of air and that creates what we call a thermal or an updraft. If you're a glider pilot you can climb until the bubble stops rising. If you're a power pilot you will experience turbulence below the altitude where the bubble stops rising.

Now this bubble started out at surface air with a specific dewpoint when it was at the surface. This dewpoint is where the blue line intersects the ground. The dark grey line shows the dewpoint of the bubble as it rises. Where it intersects the green line, the temperature of the bubble at that altitude equals it's dewpoint. A cloud forms. The little horizontal dash marks the cloudbase. There is a corresponding dash on the altitude scale to the right, so that you can read an altitude number off the scale.

>And what does moving the spot marker off of the temp line accomplish? It defines a grayed area in sort of a triangle but I haven't figured out what it's telling me.

The only grey area that I see is on the wind speed vs. altitude graph to the right of the skew-t. Dragging the cloudbash hashmark just pans the skew-t I think.

[flym...@gmail.com]

Le jeudi 27 mars 2014 12:25:32 UTC-4, kiwiindenver a écrit :
> Hi All,
>
> As a recently licensed pilot I decided it would be a good idea to learn more about soaring weather prediction, specifically the workings of a Skew-t graph.
>
> I combined that with learning more about developing Apps for Android, so yesterday I published by first Android App.
>
> https://play.google.com/store/apps/details?id=com.ajw.skewt
>
> I hope many of you find this useful.
>
> I welcome your suggestions for improvements. As I said, this is new to me.
>
> Enjoy.
>
> Alan

Bonjour

Best text to learn to read Skew-T is on the web.

Skew-T's- How to read them.
By Jim Martin
Finger Lakes Soaring Clubs
Danville NY - 2015

Gilles

[drk...@gmail.com]

Thanks for the explanation, Gilles, and the quick response. I'm a motorized pilot and not familiar with what glider drivers look for and couldn't figure out the significance of that line. Now I know.

Ray

[Charlie M. (UH & 002 owner/pilot)]

Now have a smartphone am trying it on this, may also try on my iPad (no data capabilities other than WIFI).

Thanks in advance for the work though.

[2G]

On Thursday, January 25, 2018 at 10:00:38 AM UTC-8, Charlie M. (UH & 002 owner/pilot) wrote:
> Now have a smartphone am trying it on this, may also try on my iPad (no data capabilities other than WIFI).
>
> Thanks in advance for the work though.

Does anyone remember what issue of Soaring had the article on Skew-Ts?
Tom

[Charlie M. (UH & 002 owner/pilot)]

I have a question that many may be able to answer.
I fly from Middletown, NY. ID is K06N.
When I load this in the app, it comes back with no data. Does the app find the closest sounding (we don't generate one) or do I need to find the closest sounding and Input that ID?

I also appreciate some of the links to, "reading a skew-T chart", thanks. It's been a while for me, nice to have a refresher.

[David Sherrill]

On Saturday, January 27, 2018 at 11:19:46 AM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
> I have a question that many may be able to answer.
> I fly from Middletown, NY. ID is K06N.
> When I load this in the app, it comes back with no data. Does the app find the closest sounding (we don't generate one) or do I need to find the closest sounding and Input that ID?

Try SWF.

The app does not seem to have data for smaller airports. For the Boston area, 3B3 comes up "no data" but both ORH and FIT are good.

...david

[kiwiindenver]

Hi, This is my app, im glad to hear people are still using it.

Technically my skewt app doesnt have any airports. I send the airport code to the noaa server and it gives me data if it can.

The best option if the airport is not found is to use lat/long coordinates. You can also pick from the map.

Alan

[danlj]

It's a very nice little app that sometimes doesn't succeed in obtaining data to display. I have used it often.

[Tony]

Yea I've used this app regularly for the last few years. Love it. When I've been weatherman at contests, I've often just pulled up the skew t app in the morning and had 97% of the briefing in a few seconds.

[Charlie M. (UH & 002 owner/pilot)]

Great suggestion, thanks, now I have data and can mess with it.