Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRRR) Forum

Re: RUC analysis change implementation likely tomo

Posted By: Stan Benjamin
Date: 14-October-04 2351Z

In Response To: Re: RUC analysis change implementation likely tomo (Jack Glendening)

Jack, Sorry to take so long to answer your question from 12 days ago. It is true that the PBL-depth was not over 40mb in the RUC domain other than the 15z-00z period back at the beginning of October, as you were wondering. That is probably due in part to smoothing of the PBL-depth before applying its effect in this recently implemented modification in the RUC analysis. There could be local areas where the PBL-depth exceeds 40mb overnight, but the analysis design avoids using stations over a deeper layer in such local areas. Generally, as you guessed, the new technique does not come into play overnight, as least in the past few weeks. I just checked again for the last 2 days to see when RUC cycles are affected by using the PBL depth. Again, for these past few days, most of the times affected are the 15z-00z period, but with a few stations showing up intermittently overnight. As the season moves toward winter, I expect that the period over which the new technique is used anywhere in the RUC domain with surface observations will shorten further by an hour or two at each end. Stan Jack's question from 2 October: Thanks for that info. But I puzzled over how to interpret "For the last couple of days, the use of PBL-depth in the assimilation only affects analyses between 15z and 00z." Is it that the non-daytime BL depths are smaller than the 40mb nominal depth and so the new technique does not come into play?

Messages In This Thread

RUC analysis change implementation likely tomorrow -- Stan Benjamin -- 28-September-04 1928Z

Re: RUC analysis change implementation likely tomo -- Jack Glendening -- 28-September-04 2344Z

Re: RUC analysis change implementation likely tomo -- Stan Benjamin -- 30-September-04 1913Z

Re: RUC analysis change implementation likely tomo -- Jack Glendening -- 2-October-04 1731Z

Re: RUC analysis change implementation likely tomo -- Stan Benjamin -- 14-October-04 2351Z

Re: RUC analysis change implementation likely tomo -- Geoff Manikin -- 29-September-04 1419Z

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