Change Log for Operational RUC13/20 at NCEP

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Change log - 20km operational RUC at NCEP - Apr 2002 - May 2005

17 April 2002 - 1200 UTC

Operational implementation of 20km RUC. 40km RUC-2 stops running at this point.

24 September 2002 - 1200 UTC

HYBPOST
These changes are primarily for BUFR output, including rotating winds to earth-relative (10m, profiler, storm-relative), setting 1h precip properly (instead of 3h precip on every 3rd hour), and using 2m temps, pressure, and elevation from the RUC 'topomini' file (see http://ruc.fsl.noaa.gov/forum/eval20/?read=1053). The ceiling (cloud base) calculation now properly uses the snow mixing ratio, as well as those of cloud water ice. Also, the precipitation type now properly includes sub-grid-scale precipitation (it did not before).

1 October 2002 - 1200 UTC

HYBCSTSP
Land-surface model fixes for thin snow cover. Fix to shortwave radiation cooling/heating in atmosphere.
HYBPOST
Fix so that precip type arrays output on 40km grid are not smoothed, thus avoiding substantial loss to areal coverage.

9 January 2003 - 2000 UTC

HYBPOST
A fix was made today (by Geoff Manikin and NCEP/NCO) to correct the date stamp in the RUC BUFR files. The stamp had been running 1 day ahead since January 1. The problem was in a data statement for January, and since the new format for these files began last April, it wasn't until our first January with the RUC20 that the problem surfaced.

27 May 2003 - 1200 UTC

HYBFRONT - 3-d variational analysis
A 3-d variational (3DVAR) analysis was implemented replacing the previous optimal interpolation (OI) analysis. Details in http://ruc.fsl.noaa.gov/forum/eval20/?read=1121 and in a TPB at http://ruc.fsl.noaa.gov/ppt_pres/RUC-3dvar-tpb-May03.htm.

HYBPOST
Added 0-1km helicity and fixed some other products in post processing -- described in http://ruc.fsl.noaa.gov/ppt_pres/RUC-3dvar-tpb-May03.htm.

8 July 2003 - 1900 UTC

Script producing RUC BUFR files
A fix was made today (by Geoff Manikin and NCEP/NCO) to correct a bug in this script which had resulted in the use of the early 'A' RUC analysis run at 0000 and 1200 UTC before most of the rawinsonde is available. Now the BUFR data uses the correct RUC 'B" analysis including the rawinsonde data. The 'B" analysis is the initial condition for RUC model runs at 0000/1200.

BUFR station list
A few stations were added to the BUFR station list, also added at the same time to the Eta BUFR station list.

24 Sept 2003 - 1500 UTC

HYBFRONT - gtresids_sfc_tquv.f, hybhqc.f
A couple of modifications to the 3DVAR initialization were implemented at 15Z today (24 Sep):

1. Data from land observational sites located at model water grid points will now be flagged. An example of problems associated with this data being assimilated by the model is shown at http://wwwt.emc.ncep.noaa.gov/mmb/gmanikin/ruccase/ruc_2mtcheck.gif In this example, data is available at Houghton, Michigan (located on the Keweenaw Peninsula, extending from the Upper Peninsula into Lake Superior). This peninsula is not resolved by the RUC, so the first guess for that location is colder and drier (consistent with a water point in that region) than the observation. A positive increment (difference between observation and first guess) is therefore created by the analysis code and is spread inland, causing unreasonably high temperature and especially dew point values inland over the U.P. It was determined that data from approximately 30 such land stations located at model water grid points will need to be flagged.
2. The second change is to tighten the thresholds in the quality control checks. Some bad data, particularly moisture observations, has been getting into the analysis, and limiting the permissible difference between the observed value and first guess will reduce the frequency of occurrence.

6 Oct 2003 - 1300 UTC

HYBPOST - hb2mw.f
Fix max wind level diagnostic to prevent intermittent spurious wind max values. The spline interpolation used sometimes can give wild extrapolation from RUC native levels that are very close together. This code fix constrains the spline value to be within 3% of the native level wind max, and adds some other constraints.

11 Oct 2003 - 0000 UTC

HYBETABC (HYBEXT) - (grdtr3d.f)
Fix interpolation routine for interpolating Eta grids to RUC vertical/horizontal grid for boundary conditions. Under a certain rare condition, a divide by zero could occur, so this possibility was eliminated by adding a line of code. A crash that occurred in the 12z 10 Oct run was fixed by this change.

9 Dec 2003 - 1400 UTC

HYBFRONT - (rd_cld.f,hybctp.f)
A change was made to the operational RUC at NCEP today to fix a cloud assimilation error. Cloud was inadvertently being cleared in situations with partial cloud cover in the GOES data in the proximity of a grid point. The overall impact is fairly minor.

14 April 2004 - 1200 UTC