Welcome, Guest
Username: Password: Remember me
Forgot your password? Forgot your username?
Forum
OpenGribs Forum
Gribs and Models
WRF 4km - Difference in forecast between 00Z &12Z runs
×

No Bulk Downloads - PLEASE!

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

TOPIC:

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #945

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 37
  • Thank you received: 0
Hi,
In recent days I have noticed that the (WRF Israel 4km) model forecasts for the two runs 00Z & 12Z differ from each other especially for the precipitation and simulated radar reflectivity (dBZ).
Is this due to the use of different cumulus, micro-physics and radiation schemes in the two runs 00Z & 12Z?

Please let us know what new changes have recently been made to the WRF 4km model and the reasons for the difference between the two runs, as I am no longer able to know which run is more accurate and which forecasts to take.

Thank you.

Please Log in to join the conversation.

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #946

Hi Ameer,
The 00Z and 12Z runs are on different machines but they are using the same version of WRF and the same setup for physics schemes. You might try to check the difference in precipitation between the 00Z and 12Z GFS forecasts as this might be the source of the difference that you noticed.
Regards,
David

Please Log in to join the conversation.

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #947

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 37
  • Thank you received: 0
Hi David,
I have checked the 00Z and 12Z GFS forecasts and there is no difference between the two runs.
As I mentioned, the difference between the 00Z and 12Z WRF forecasts is large and clear and it has happened many times.

The difference is clear in the precipitation forecast for yesterday 00Z30SEP and 12Z30SEP, and also for today 00Z01OCT and 12Z01OCT.
Precipitation in the 12Z run appears to have been overestimated for both days. This issue also occurred last month as I observed it starting with the 12Z12SEP2023 run when the precipitation forecast was significantly overestimated.

Thank you.

Please Log in to join the conversation.

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #948

Hi Ameer,
I checked again and found that the two runs were using different cumulus schemes. They are now both set to the less sensitive scheme that should not grossly overestimate precipitation.
Best,
David

Please Log in to join the conversation.

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #949

  • ameerrh
  • ameerrh's Avatar Topic Author
  • Offline
  • Junior Member
  • Junior Member
  • Posts: 37
  • Thank you received: 0
Hi David,
Are both runs (00Z and 12Z) now using the same cumulus scheme?

Besides, I also noticed in the last two days and today (for both runs 00Z and 12Z) that the WRF model predicted the simulated radar reflectivity (dBZ) with high values (40-55 dBZ) in many areas but without predicting any precipitation in these areas.
Is there any issue regarding simulated radar reflectivity forecast (i.e., issues in schemes or settings used)?
I believe that these high values (40-55 dBZ) mean that there is rain, thunderstorms and possibly hail.

Thank you very much.

Please Log in to join the conversation.

WRF 4km - Difference in forecast between 00Z &12Z runs 2 years 11 months ago #950

Yes, both runs are using exactly the same physics schemes including the cumulus scheme.
I hope to see improvement in precipitation forecasts.

Please Log in to join the conversation.
  • Page:
  • 1
Forum
OpenGribs Forum
Gribs and Models
WRF 4km - Difference in forecast between 00Z &12Z runs
Time to create page: 0.030 seconds
Go to top