<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[Why same model (ECMWF) differ in other sites&#x2F;apps]]></title><description><![CDATA[<p dir="auto">I need an explanation:</p>
<p dir="auto">Comparing two sites (<a href="http://windy.com" rel="nofollow ugc">windy.com</a> and windy.app) for the forecast of absolutely the same spot in the mountain using absolutely the same model - ECMFW, there is great difference in the temperature, snow accumulation etc.</p>
<p dir="auto"><a href="http://Windy.com" rel="nofollow ugc">Windy.com</a> says there would be 0.1cm of snow accumulation but windy.app says there will be 9cm. The temperature differ from -10C (windy.app) to -5C (<a href="http://windy.com" rel="nofollow ugc">windy.com</a>).</p>
<p dir="auto">I am talking about a forecast for the same day. Not 6 days from now.<br />
Using the premium version of both sites and once again - the same model!</p>
<p dir="auto">Thanks.</p>
]]></description><link>https://community.windy.com/topic/31111/why-same-model-ecmwf-differ-in-other-sites-apps</link><generator>RSS for Node</generator><lastBuildDate>Wed, 14 Oct 2026 13:46:45 GMT</lastBuildDate><atom:link href="https://community.windy.com/topic/31111.rss" rel="self" type="application/rss+xml"/><pubDate>Sat, 27 Jan 2024 19:24:51 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 21:49:03 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
I do not ask you to do your own calculations with the raw data, just to imagine this</p>
<p dir="auto"><img src="/assets/uploads/files/1707860855253-3c376b26-39b4-4940-8660-89483c9a37ec.jpeg" alt="3C376B26-39B4-4940-8660-89483C9A37EC.jpeg" class=" img-fluid img-markdown" /></p>
<p dir="auto">This has been already asked to Windy…</p>
]]></description><link>https://community.windy.com/post/179142</link><guid isPermaLink="true">https://community.windy.com/post/179142</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Tue, 13 Feb 2024 21:49:03 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 21:03:22 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/idefix37" aria-label="Profile: idefix37">@<bdi>idefix37</bdi></a> said in <a href="/post/179113">Why same model (ECMWF) differ in other sites/apps</a>:</p>
<blockquote>
<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
Yes, but you must know that the weather model calculations are all based on air pressure levels, not on real elevation.<br />
However it would be useful to display the average elevation corresponding to these pressure levels. As it is displayed just below for clouds but not very detailed:</p>
<p dir="auto"><img src="/assets/uploads/files/1707846174254-3374cf09-2f4f-4cb1-b00b-50bafe3e0730.jpeg" alt="3374CF09-2F4F-4CB1-B00B-50BAFE3E0730.jpeg" class=" img-fluid img-markdown" /></p>
<p dir="auto">Or you need to make your own pressure / averaged elevation scale yourself.</p>
</blockquote>
<p dir="auto">I understand and know that most of the calculations are based on the air pressure levels but that doesn't change the fact it's not convenient for the normal user.</p>
<p dir="auto">This is exactly every application's "you had one job" thing - to process the information and present it in a understandable way.</p>
<p dir="auto">If I wanted to do my own calculations with the raw data then I would not use any app at all.</p>
<p dir="auto">Anyway - that was just a suggestion for improving the UI.</p>
]]></description><link>https://community.windy.com/post/179135</link><guid isPermaLink="true">https://community.windy.com/post/179135</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 21:03:22 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 18:43:56 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
Yes, but you must know that the weather model calculations are all based on air pressure levels, not on real elevation.<br />
However it would be useful to display the average elevation corresponding to these pressure levels. As it is displayed just below for clouds but not very detailed:</p>
<p dir="auto"><img src="/assets/uploads/files/1707846174254-3374cf09-2f4f-4cb1-b00b-50bafe3e0730.jpeg" alt="3374CF09-2F4F-4CB1-B00B-50BAFE3E0730.jpeg" class=" img-fluid img-markdown" /></p>
<p dir="auto">Or you need to make your own pressure / averaged elevation scale yourself.</p>
]]></description><link>https://community.windy.com/post/179113</link><guid isPermaLink="true">https://community.windy.com/post/179113</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Tue, 13 Feb 2024 18:43:56 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 17:26:38 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/idefix37" aria-label="Profile: idefix37">@<bdi>idefix37</bdi></a> said in <a href="/post/179106">Why same model (ECMWF) differ in other sites/apps</a>:</p>
<blockquote>
<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
What you call the “forecast grid” is probably the Basic meteogram called Basic in Windy. For the freezing level you just need to switch on Airgram, as <a class="plugin-mentions-user plugin-mentions-a" href="/user/filip_k" aria-label="Profile: Filip_K">@<bdi>Filip_K</bdi></a> said.<br />
I don’t know if a customisable meteogram could be made. Probably not easy.</p>
</blockquote>
<p dir="auto">I checked the Airgram but as mentioned before - the reference axis for the freezing level is air pressure not altitude which is not useful, at least not for me.</p>
]]></description><link>https://community.windy.com/post/179111</link><guid isPermaLink="true">https://community.windy.com/post/179111</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 17:26:38 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 16:31:03 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
What you call the “forecast grid” is probably the Basic meteogram called Basic in Windy. For the freezing level you just need to switch on Airgram, as <a class="plugin-mentions-user plugin-mentions-a" href="/user/filip_k" aria-label="Profile: Filip_K">@<bdi>Filip_K</bdi></a> said.<br />
I don’t know if a customisable meteogram could be made. Probably not easy.</p>
]]></description><link>https://community.windy.com/post/179106</link><guid isPermaLink="true">https://community.windy.com/post/179106</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Tue, 13 Feb 2024 16:31:03 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 16:16:20 GMT]]></title><description><![CDATA[<p dir="auto">Yes, that's what I thought. It's not really useful in that configuration but hopefully it will get added in the forecast grid.</p>
]]></description><link>https://community.windy.com/post/179105</link><guid isPermaLink="true">https://community.windy.com/post/179105</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 16:16:20 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 15:52:02 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
I'm afraid only map and airgram display freezing level.</p>
<p dir="auto">In airgram, freezing level is the white line between blue and green mass. And the left axis is in pressure levels which makes it quite difficult to get actual freezing altitude.<br />
<img src="/assets/uploads/files/1707839370303-screenshot_20240213_154821.png" alt="Screenshot_20240213_154821.png" class=" img-fluid img-markdown" /></p>
<p dir="auto">But picker displays such value anywhere:<br />
<img src="/assets/uploads/files/1707839519793-screenshot_20240213_155155.png" alt="Screenshot_20240213_155155.png" class=" img-fluid img-markdown" /></p>
]]></description><link>https://community.windy.com/post/179103</link><guid isPermaLink="true">https://community.windy.com/post/179103</guid><dc:creator><![CDATA[Filip_K]]></dc:creator><pubDate>Tue, 13 Feb 2024 15:52:02 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 15:33:51 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/filip_k" aria-label="Profile: Filip_K">@<bdi>Filip_K</bdi></a> said in <a href="/post/179096">Why same model (ECMWF) differ in other sites/apps</a>:</p>
<blockquote>
<p dir="auto">Hi <a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a>, already available: <a href="https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5" rel="nofollow ugc">https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5</a></p>
</blockquote>
<p dir="auto">Oh, great.</p>
<p dir="auto">Can I add it into the "forecast window" with the wind/temp/snow/rain/etc or I can see it only on the map when I move it around? Because when I choose one of my saved favourite spots the freezing level is not shown.</p>
<p dir="auto">Thanks again.</p>
]]></description><link>https://community.windy.com/post/179101</link><guid isPermaLink="true">https://community.windy.com/post/179101</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 15:33:51 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 15:08:54 GMT]]></title><description><![CDATA[<p dir="auto">Hi <a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a>, already available: <a href="https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5" rel="nofollow ugc">https://www.windy.com/-Show---add-more-layers/overlays?deg0,48.546,31.399,5</a></p>
]]></description><link>https://community.windy.com/post/179096</link><guid isPermaLink="true">https://community.windy.com/post/179096</guid><dc:creator><![CDATA[Filip_K]]></dc:creator><pubDate>Tue, 13 Feb 2024 15:08:54 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 15:03:39 GMT]]></title><description><![CDATA[<p dir="auto">Well, okay, so we can assume the <a href="http://windy.com" rel="nofollow ugc">windy.com</a> forecast should be more accurate.</p>
<p dir="auto">Would've been great if I could stay at a mountain hut and just make a prospective trail comparing the two forecasts :)</p>
<p dir="auto">Anyhow.</p>
<p dir="auto">One more question which is offtopic - as I can see few of you are developers/moderators - do you consider adding a "freezing level" line as in the windy.app interface? That feature I must say is really handy. Thanks.</p>
]]></description><link>https://community.windy.com/post/179094</link><guid isPermaLink="true">https://community.windy.com/post/179094</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 15:03:39 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 14:27:39 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a></p>
<p dir="auto">At the altitude of your ski resort, 25km resolution vs 9km resolution that makes a big difference. In addition model updates can be different.<br />
Check the run time of the models, called the Reference time in Windy.</p>
<p dir="auto"><img src="/assets/uploads/files/1707833888897-98fbf2e1-db55-41e9-a99c-0c5afba5be84.jpeg" alt="98FBF2E1-DB55-41E9-A99C-0C5AFBA5BE84.jpeg" class=" img-fluid img-markdown" /></p>
]]></description><link>https://community.windy.com/post/179090</link><guid isPermaLink="true">https://community.windy.com/post/179090</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Tue, 13 Feb 2024 14:27:39 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Wed, 14 Feb 2024 07:43:53 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a><br />
<a class="plugin-mentions-user plugin-mentions-a" href="/user/filip_k" aria-label="Profile: Filip_K">@<bdi>Filip_K</bdi></a></p>
<p dir="auto">In fact for the atmosphere parameters windy.app is probably using the free version of IFS which comes with a 25km resolution. It is called “WMO essentials”.<br />
But for sea parameters they use the 14km resolution model.<br />
At ECMWF there is no 14km resolution model for the atmosphere parameters as you can see :<br />
<a href="https://confluence.ecmwf.int/plugins/servlet/mobile?contentId=324860211#content/view/324860211" rel="nofollow ugc">https://confluence.ecmwf.int/plugins/servlet/mobile?contentId=324860211#content/view/324860211</a><br />
They deceive the users using the 14 km resolution as the general resolution of the ECMWF forecast they show.</p>
]]></description><link>https://community.windy.com/post/179086</link><guid isPermaLink="true">https://community.windy.com/post/179086</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Wed, 14 Feb 2024 07:43:53 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 12:40:32 GMT]]></title><description><![CDATA[<p dir="auto">Hi <a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a>, according to <a href="https://windy.app/blog/what-is-ecmwf-weather-forecast-model.html" rel="nofollow ugc">this article</a>, windy.app uses some other model from ECWMF (14km resolution, updated twice a day). ECMWF-HRES model on <a href="http://windy.com" rel="nofollow ugc">windy.com</a> has 9km resolution and is updated 4 times a day.</p>
]]></description><link>https://community.windy.com/post/179082</link><guid isPermaLink="true">https://community.windy.com/post/179082</guid><dc:creator><![CDATA[Filip_K]]></dc:creator><pubDate>Tue, 13 Feb 2024 12:40:32 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Tue, 13 Feb 2024 12:28:14 GMT]]></title><description><![CDATA[<p dir="auto">Alright, let's try again. Here are two screenshots - windy.app and <a href="http://windy.com" rel="nofollow ugc">windy.com</a> showing absolutely the same spot at the same time. One of the forecasts has been updated almost 1 hr ago, and the other one - almost 4hrs ago, hence 3hrs difference (but I must say that there was the same pattern of discrepancy between the two even when the update times were in favour of the other app.)</p>
<p dir="auto">As you may see: Per windy.app the calculated snowfall is almost TRIPLE as much as per <a href="http://windy.com" rel="nofollow ugc">windy.com</a>.</p>
<p dir="auto">Something is just not right - I cannot wrap my head around how the same forecast model has that much of discrepancy between two different apps. The 3hrs difference in the update time cannot be a legitimate reason. If a forecast model cannot predict the weather for the SAME day why does it exist at all?</p>
<p dir="auto"><img src="/assets/uploads/files/1707827227661-img_2454.png" alt="IMG_2454.PNG" class=" img-fluid img-markdown" /> <img src="/assets/uploads/files/1707827226379-img_2453.png" alt="IMG_2453.PNG" class=" img-fluid img-markdown" /></p>
]]></description><link>https://community.windy.com/post/179081</link><guid isPermaLink="true">https://community.windy.com/post/179081</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Tue, 13 Feb 2024 12:28:14 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Mon, 29 Jan 2024 08:27:56 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a></p>
<p dir="auto">You may try to compare the Snow depth by ECMWF themselves {run time  12z - 01 27)</p>
<p dir="auto"><img src="/assets/uploads/files/1706396080939-84842c31-7e10-4c2c-a172-6acc9bf863f3-resized.png" alt="84842C31-7E10-4C2C-A172-6ACC9BF863F3.png" class=" img-fluid img-markdown" /></p>
<p dir="auto">With the same parameter at same date by <a href="http://windy.com" rel="nofollow ugc">windy.com</a> (same run time ):</p>
<p dir="auto"><img src="/assets/uploads/files/1706396182379-cd71cdd8-975f-4d7f-8683-5a26d8dabdb9.jpeg" alt="CD71CDD8-975F-4D7F-8683-5A26D8DABDB9.jpeg" class=" img-fluid img-markdown" /></p>
<p dir="auto">These 2 maps are identical.</p>
]]></description><link>https://community.windy.com/post/177190</link><guid isPermaLink="true">https://community.windy.com/post/177190</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Mon, 29 Jan 2024 08:27:56 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Sat, 27 Jan 2024 21:39:18 GMT]]></title><description><![CDATA[<p dir="auto">I am completely aware that <a href="http://windy.com" rel="nofollow ugc">windy.com</a> and .app are different things. That's why I am comparing them.</p>
<p dir="auto">I check and compare them throughout the day a few times. And not on one occasion as well. For different spots as well.</p>
<p dir="auto">The reference time is almost exactly the same - about an hour difference. The model in windy.app is 14km resolutions as per their site. I don't think that's so great of a difference.</p>
<p dir="auto">Anyway, it's just frustrating. I am mainly a winter user and the main objective is temp, snow, wind. I just wanted to know where the difference in snow accumulation comes from, because if one of the sites was saying snow 1,00m and the other 1,10m - that's fine, 10% difference not big deal. But between 10cm and 0cm it's quite the opposite. Anyhow, it is what it is.</p>
]]></description><link>https://community.windy.com/post/177186</link><guid isPermaLink="true">https://community.windy.com/post/177186</guid><dc:creator><![CDATA[Dimitar Mihaylov]]></dc:creator><pubDate>Sat, 27 Jan 2024 21:39:18 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Sat, 27 Jan 2024 19:55:26 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a></p>
<p dir="auto">In case you don’t know, <a href="http://Windy.com" rel="nofollow ugc">Windy.com</a> and Windy.app are two different companies.  The code behind the two forecast displays will likely be different.</p>
<p dir="auto">The other thing you need to check is the Reference time for the forecast.  This is the time that the predictive model is loaded with current conditions.  It can take 6 hours of compute time before the model actually comes out with a new forecast.</p>
<p dir="auto">Some sites are quicker than others in updating when a new forecast is released.  <a href="http://Windy.com" rel="nofollow ugc">Windy.com</a> is pretty quick so it could be that Windy.app is still displaying the previous forecast update while <a href="http://Windy.com" rel="nofollow ugc">Windy.com</a> is showing the latest one.  It that case, predictions can vary a lot.  Alway check the forecasts Reference time, and make sure they agree, if you want to compare them.</p>
]]></description><link>https://community.windy.com/post/177171</link><guid isPermaLink="true">https://community.windy.com/post/177171</guid><dc:creator><![CDATA[btschumy]]></dc:creator><pubDate>Sat, 27 Jan 2024 19:55:26 GMT</pubDate></item><item><title><![CDATA[Reply to Why same model (ECMWF) differ in other sites&#x2F;apps on Sun, 28 Jan 2024 07:49:03 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/dimitar-mihaylov" aria-label="Profile: Dimitar-Mihaylov">@<bdi>Dimitar-Mihaylov</bdi></a></p>
<p dir="auto">Check these 2 points:</p>
<ul>
<li>Are the run time (reference time) exactly the same in both apps when you make your observation ?</li>
<li>Is the resolution of the model the same ? In <a href="http://windy.com" rel="nofollow ugc">windy.com</a> the resolution of the ECMWF model is 9km:  This is the high resolution version which requires high costs. Many weather apps use the free version of this model with a resolution of around 40 km.</li>
</ul>
]]></description><link>https://community.windy.com/post/177170</link><guid isPermaLink="true">https://community.windy.com/post/177170</guid><dc:creator><![CDATA[idefix37]]></dc:creator><pubDate>Sun, 28 Jan 2024 07:49:03 GMT</pubDate></item></channel></rss>