Welcome, Guest
Username: Password: Remember me
26 Sep 2020
No bulk downloads - PLEASE! THIS IS OVERLOADING OUR SERVER AND DENYING ACCESS TO COMMUNITY USERS
SVP - Pas de téléchargement en masse ! Cela surcharge le serveur et empêche la communauté d'utilisateurs d'accéder aux données
_______________________________
WE WILL BLOCK IP'S THAT ARE BULK DOWNLOADING! Nous bloquerons les IPs des personnes qui agissent de la sorte.
PLEASE GO DIRECTLY TO THE GRIB PRODUCERS (NOAA, DWD...) FOR BULK DOWNLOADS. Allez chercher les données directement à la source (NOAA, DWD ...)
Read More...
  • Page:
  • 1
  • 2

TOPIC:

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #890

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 25
  • Thank you received: 0
Hi,
Why there is a big difference in precipitation forecast between the two references 00Z23SEP2021 & 12Z23SEP2021 in the WRF Israel 4km?
Ref:12Z23SEP2021 seems to underestimate the precipitation significantly. This is very clear when comparing the two references 00Z and 12Z as shown in the screenshots below. I think there is an issue.

Screenshots for the Ref: 00Z23SEP2021

Please Log in or Create an account to join the conversation.

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #891

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 25
  • Thank you received: 0
Screenshots for the Ref: 12Z23SEP2021 for the same forecast times as in the screenshots above.

Please Log in or Create an account to join the conversation.

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #892

Hi,
There is an explanation. The 12z run is using a different configuration to try to improve precipitation forecasts. The 00Z run is without any changes.
For the next few rainy days I will be trying different cumulus, micro-physics and radiation schemes on the model. I already see that the cumulus scheme is not so great.
David

Please Log in or Create an account to join the conversation.

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #893

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 25
  • Thank you received: 0
Hi,
I think there was an issue in the precipitation forecast and also in the simulated radar reflectivity (dBZ) forecast for the last days in the 12z run with this different configuration. Was this issue caused by the settings of this new configuration or is there another reason?

Has this different configuration been used in the last few days without the cumulus scheme?

Thanks

Please Log in or Create an account to join the conversation.

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #894

The 12Z forecast has been running with a different configuration for the last few weeks. When there is no precipitation in the atmosphere the difference will not be noticed.
Now that there was some precipitation in the last two days the differences are noticeable. From the last 12Z forecast the cumulus scheme is the same as the 00Z forecast but the radiation (both short and longwave) and the microphysics schemes are different.
David

Please Log in or Create an account to join the conversation.

WRF 4km - Difference in precipitation forecast between 00Z23SEP2021&12Z23SEP2021 2 months 1 week ago #895

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 25
  • Thank you received: 0
Hi,
I also noticed that the forecast of simulated radar reflectivity (dBZ) is different in the 12z run.

Is this due to the use of different radiation and the microphysics schemes?
Can this change in the simulated radar reflectivity forecasting (as shown in screenshots below) be considered an issue or is it evidence of improved forecasting?

Attachments:

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
  • 2
Time to create page: 0.116 seconds

Resources on this site will always be free and open with no commercialization. However, operating costs of the servers to pre-process and deliver GRIB files to XyGrib are not trivial.

If you found the site useful, please share in the effort and help keep us up and running

 

Please Support

Go to top