• Opera Snapshot_2020-05-18_020434_www.windy.com.png It's appearing clearly from the temp. report that rain has fallen. but, nothing is appearing on the station condition display, Although the airport METAR system has detected the rainfall.

  • Sailor Moderator

    It is because rain is not always shown in the weather station observations on Windy.
    Mainly temperature, dew point, wind speed and wind direction, and only for few stations, rain and wind gusts in addition. I don’t know why there are these differences between weather stations reports on Windy.
    It is not an error just a missing information.

  • I guess Windy displays values of all main weather parameters (rain is one of them).... IF provided by a given station. Thus, all WMO stations providing SYNOP messages should contain rain observed values (but only at some hours) on Windy maps, while not all personal, not WMO stations, have rain gauges.

  • This is an international airport which must be provided with radar which can detect any weather event. From the picture you can see clearly that the METAR system has detected the event but nothing is appearing on condition display. Here is another good example.Opera Snapshot_2020-05-18_152247_www.windy.com.png You can see clearly rain and thunder rain from the picture.

  • Try to zoom more; as one can see, actually there are two different weather stations on that airport (screenshot), like on many other airports:

    • wmo 62405: (left side), WMO station which provides SYNOP messages (it has 5 digits WMO ID, this it is part of the GTS network), and has well a rain gauge
    • ad HELX: (right side), I don't know what it is nor what means prefix ad. It is the incriminated station in your posts above and may be simply a METAR station which doesn't have a rain gauge (planes often don't need an umbrella :o)))


  • Moderator

    "ad" = aerodrome (airport)

  • OK, thanks. Then "HELX" would be the ICAO identifier of that station which should simply provide METAR messages without the rain group, while the neighbor SYNOP station does provide it. Finally, nothing is missing on Windy maps :o)))

    About HELX station and Rain: I've just checked ALL METAR messages provided this month month (from Ogimet); a priori only one of all these messages contained "RA" (i.e. rain).... I'm not an expert in decoding METAR messages, but afaik. a METAR doesn't contain precipitation amount in the same manner as it can be found in SYNOP messages (I think that for aviation, rain is rather important from visibility pov.).

    Btw. I did the same exercice with SYNOM messages from WMO station 62405; there are many messages this month which contain group 6 (for precipitation amount...)

  • Moderator

    Metars always include sign. phenomena (and rain) group.
    In the screenshot
    we see thunderstorm with rain on Sunday 17 May afternoon.

    HELX metars are:
    METAR HELX 172300Z 12003KT 6000 SCT020 29/14 Q1006 NOSIG=
    METAR HELX 172200Z 16004KT 6000 SCT020 32/12 Q1007 NOSIG=
    METAR HELX 172100Z 08008KT 6000 BKN020 34/12 Q1007 NOSIG=
    METAR HELX 172000Z 17007KT 6000 BKN020CB 34/13 Q1007 NOSIG=
    METAR HELX 171900Z 03006KT 6000 BKN020CB 34/13 Q1007 NOSIG=
    METAR HELX 171800Z 03004KT 6000 BKN020CB 32/17 Q1006 NOSIG=
    METAR HELX 171700Z 01016KT 2000 SA BKN020CB 32/17 Q1006 NOSIG=
    METAR HELX 171600Z 26012KT 2000 TSSA BKN020CB 36/16 Q1004 NOSIG=
    METAR HELX 171500Z 25012KT 9999 TS SCT020CB 36/16 Q1004 NOSIG=
    METAR HELX 171400Z 23008KT 9999 TS SCT020CB 40/14 Q1004 NOSIG=
    SPECI HELX 171335Z 22012KT 9999 TS SCT020CB 42/13 Q1004 NOSIG=
    METAR HELX 171300Z 06008KT 9999 SCT020 43/17 Q1004 NOSIG=
    METAR HELX 171200Z 08010KT 9999 FEW030 42/16 Q1005 NOSIG=

    SYNOPS are

    according to observations (wx. reports)
    at 17/1335Z there is a speci (-al report) of TS (thunderstorm heard)
    at 14Z and 15Z the same.
    at 16Z, TS and visibility droped down to 2 km due to SAnd (not due to rain).
    at 17Z, visibility remains at 2km due to SAndstorm. No thunder heard.
    at 18Z, visibility improved to 6 km.

    From SYNOPs the precipitation amount is 0.0 mm.
    That means no rain recorded (although some traces from droplets may occur).
    It was a dry thunderstorm https://en.wikipedia.org/wiki/Dry_thunderstorm
    and the visibility were reduced due to sandstorm.

    I think there is a minor bug in Windy's decoder.
    On Sunday afternoon it shows (erroneously) thunderstorm with rain.
    The render read TS and translated it with a wrong symbol.


  • @Gkikas-LGPZ That exactly what I meant.

Windyty, S.E. - all rights reserved. Powered by excellent NodeBB
NodeBB & contributors, OSM & contributors, HERE maps
Terms and Conditions     Privacy Policy