Posts made by mrpetewx

Has anyone else noted just how awful some of the models are, for hurricane forecasts?

I had great interest in Beryl, as a family member lives on the Yucatan peninsula. Three models available: NHC-At, UKM, ECMWF

In general, NHC-At has been pretty good, ECMWF unrealistically low, and UKM truly crazy-low.

On Wed as Beryl approached Jamaica, I noted that just after a forecast update the discrepancy became rather extreme. Current wind speed was ~140mph. The noon forecast, only a few hours later, was literally a drop to half that in the UKM model, and a bit less extreme in ECMWF. Even 3 hours before noon, with wind speed increasing, the UKM forecast only increased to 80mph.

The result: only the NHC-At model gave me any sense that it could produce a believable forecast.

Why are the other two models used at all for this purpose?

The Windy overview of ECMWF says:

ECMWF 9km
Very accurate model provided by the 
European Centre for Medium-Range Weather
 Forecasts. Clear winner compared to other 
forecast models.

That may be true in some categories. For snow (levels and new) it is horrifically false, at least at altitude (mountains or not.)

The following is a typical example:

We live at 7050 ft on high plains in Colorado Springs. Just finished a two day round trip to Monte Vista, CO (7500 ft high plains) and nearby NWRs via La Veta Pass.

There was no snow on the ground at any time (except maybe an inch in some shaded north facing slope spots at the top of the pass.)

ECMWF thought we were seeing a foot or more of snow almost everywhere we went, and no less than a half inch except from ~ Pueblo to Walsenburg. (Ground modeled-reality and forecast)

In our region, ICON is far more accurate for snow, both existing depth and new snow.

SUGGESTIONS:

• Correct the above summary text
• Consider support for different models for different data streams.

Thbanks!

@Ondřej-Šutera Is there a place for feature suggestions?

The reason for this thread is that it would be wonderful to have snow forecast in the embed forecast during cold months 🤠

Is there a limit to how many (time stamped) observations can be uploaded in a single API call? I don't see a reason why it would fail, but the docs don't say one way or another.

I'm planning to write a catch-up function for weewx similar to what is available for other wx online databases :)

@Ondřej-Šutera can I do layers in the forecast?

@Ondřej-Šutera my real question is about the embed URL interface, and how to enable temp isoline.

As you see above, I was told that isolines are not supported even in the API. Clearly they are.

Do you know if temp isoline is, or may be, supported in embed URL's?

@Ondřej-Šutera at 7000 ft in Colorado, there is very little relationship between predicted precipitation and predicted snowfall.

I just confirmed the hard way. Both guesses are correct.

When you click "show key",a new key is generated, and the existing key is no longer valid.

Is there a limit to how many (time stamped) observations can be uploaded in a single API call?

I'm planning to write a catch-up function similar to what is available for other wx online databases :)

@Korina (again, my apologies for looong delayed reply. Dealing with the passing of a crucial coworker :( )

I never see snow in the embedded forecast. What am I missing?

https://embed.windy.com/embed2.html?lat=38.851&lon=-104.769&detailLat=38.851&detailLon=-104.769&width=650&height=450&zoom=5&level=surface&overlay=wind&product=ecmwf&menu=&message=&marker=&calendar=now&pressure=&type=map&location=coordinates&detail=&metricWind=default&metricTemp=default&radarRange=-1&detail=true

@Korina I'm confused. Was it a typo to say "isolines are not included in the API"??

Everywhere in the v4 API, isolines are mentioned. And the javascript contains info about isolines = pressure, temp (and sometimes gh or deg0).

The Embed tool also includes a checkbox for "Pressure isoline", which incorporates this into the iframe src URL: &pressure=true

So, what were you really trying to say please? Thanks!

@Korina THANK YOU for the rapid response! I'm sorry it took me so long to get back to you... lots of Real Life stuff.

Of course I understood about turning on spot forecast. That's part of my report.

I've played with this a bit more now.

While it does not redraw "forever", it easily redraws a LOT more than 2-3 times. Depending on the situation, I have now seen it take 10-20 redraws before it stops.

Not sure what's going on: some of the redraws seem to move the map center. Many do not. Clearly it's attempting to put the current spot in the visible map.

My thought: perhaps it should NOT redraw or auto-recenter at all in the builder? After all, the user is most likely scrolling and zooming to choose the place for their desired spot :)

I've got a PWS that's been publishing for well over a year. I just added it to the Windy API (Weewx plugin).

Strangely, while data has uploaded every 5 minutes for many hours,

• the station doesn't show up in a search at all
• and using the API only shows the first data point uploaded

THEN, when going back to verify my key, I noticed that it had changed. AND MOST IMPORTANT: every time I try to view the key, I get a brand new key?!!

By any chance, is the "show key" button actually a "generate new key" button?
By any chance, does that invalidate the existing key?

THAT would explain a lot :). If so, please update the stations page to explain this clearly!

(AND, I hope that random users cannot cause the station key to be invalidated. That would be truly awful...)

@czollars (Just to answer for others who stop by: must be root to install the plugin.)

I've replicated the following in both Chrome and MS Edge browsers:

• Bring up the Embed "builder" UI (eg here)
• Zoom in a little (not sure this is necessary)
• Turn on the Spot forecast
• Now click-drag the map down/right, (scrolling to mark the correct location for the spot forecast, a spot NW of what I see)

Not every time, but incredibly easy to replicate the UI going into an endless loop. The following is what I see, and is my guess as to the actual bug

• Draws with forecast
• But forecast covers the current spot
• So it redraws without forecast
• Yet I dragged the map and actually want to mark a spot that will move the old spot off the map
• So it moves the map (but hasn't yet moved the spot -- is this the bug?)
• And we're back to step one in the loop!

The optionally embedded spot forecast (&detail=true) is wonderful in many ways.

However, it has one weakness: in regions where winter is typically cold

• the rainfall forecast is useless
• a snow forecast would be quite useful

Any way that could be settable and/or automatically adjusted?

When I look at the various API's, both commercial and free, it appears that both pressure and temperature isolines are supported pretty much across the board.

However, I can't find documentation or examples of how to enable temp isoline in an embedded/iframe URL.

Is that possible, or did I just create a feature request? ;)

Thanks heaps!