1. A Few Issues Regarding the Use of Q2 (and related) products and software at NCEP/EMC Curtis H. Marshall NCEP/EMC Q2 Science Workshop NSSL Norman, OK June 28-30 2005

2. Background Currently: NCEP/EMC uses Stage II/IV for precipitation assimilation in NDAS  model is nudged to observed precipitation during assimilation cycle  model temperature, moisture, and cloud fields are adjusted to be more consistent with observed precipitation  also: land-surface model receives the observed precipitation (in lieu of model precipitation) -> influence on surface energy budget and subsequent convective precipitation

3. Background Current work: towards “assimilation” of cloud and hydrometeors  first step: using Z-R and Z-M relationships, develop forward model and nudge model hydrometeor concentrations  adjust model temperature, moisture, and momentum fields to be consistent with “observed” hydrometeors  PRELIMINARY target: WRF-NMM implementation in March 2006

4. The Plan Required data: gridded, quality-controlled WSR- 88D reflectivity data  Level-II data stream now flowing through LDM/TOC into NCO  Adapt NSSL single radar QC code at NCEP (currently underway)  Use NSSL reflectivity Mosaic code to construct national realtime mosaic operationally at NCEP  Nudge towards the 3-D analysis of reflectivity in WRF- NMM data assimilation cycle

5. Potentially….  Distribution of reflectivity mosaic to service centers and other customers?  Hosting an operational version of NMQ on NCEP computing platform?  Production and distribution of other NMQ (e.g., QPE) products?

6. … Some Issues  The requirement must be defined for NCEP  Need assurances of operational support (who to call 24/7 if something goes awry?)  Would like to see a side-by-side long-term (annual cycle?) verification of NMQ QPE against Stage II/IV  NCEP NOT in a position to provide end user support to potential customers of NMQ products!

7. FEEDBACK? Thanks!