ungrib.exe -- "Data not found"

[snoopy]

Hi guys, I am a new user of WRF.
After practicing the default case according to the online tutorial, I tried to use the data from GFDL to run WRF. However, I met some proble when running ungrib.exe.

My data is in grib1 format. One variable with a series times is in one file. Every variable has the same time series from 2000-01-16 to 2000-12-16 with one value in each month. I had 20 variables, so there were 20 files. When I was running ungrib.exe, the error information occurred:

Error opening GRIBFILE.AAU Error status: 2
INFORM: First pass done, doing a reprocess
Begin rrpr
Subroutine DATINT: Interpolating 3-d files to fill in any missing data...
Looking for data at time 2000-01-16_12
ERROR: Data not found: 2000-01-16_12:00:00.0000
FORTRAN STOP

Actually, my data is only from GRIBFILE.AAA to GRIBFILE.AAT; that is, I do not have GRIBFILE.AAU.
How can I solve it? Has anybody met with this problem before?
Looking forward your reply!
Thank you very much!

[wrfhelp]

Are you using average data as input?
You should have use instantaneous data at a temporal resolution of 12h or higher for input.

wrfhelp

[snoopy]

Yes, my data is monthly averaged. Ok, I see. Thank you very much!

[lilyzh]

Are you using average data as input?
You should have use instantaneous data at a temporal resolution of 12h or higher for input.

wrfhelp

I can use original NCEP NARR 3-hourly files to run, but time of downloading the data is too much. So I decide to use NCEP's NARR monthly means. However, it appeared the same problem "Data not found" when running ungrib.exe. I am not sure if NCEP's NARR monthly means can be used in WRF, or if the Vtable. NARR is not fit for NCEP's NARR monthly means? I am a new WRF user. Could you give me any advice?

Thank you.