1. 1 Evolution and Priorities for OCONUS and CONUS Guidance Systems including a convection permitting ensemble system Presented By: Geoff DiMego (NCEP/EMC) Contributors: Stan Benjamin, Curtis Alexander (ESRL/GSD) Jacob Carley, Brad Ferrier, Eric Rogers (NCEP/EMC) Jack Kain, Lou Wicker (NSSL), Israel Jirak (NCEP/SPC)

2. 2 Operational System Attribute(s) System NameAcronymAreal Coverage Horz ResCycle Freq Fcst Length (hr) Rapid RefreshRAPN. America13 km1 hr18 High Resolution Rapid RefreshHRRRCONUS3 km1 hr15 North American MesoscaleNAMN. America12 km6 hr84 North American Mesoscale NestsNAMnestO/CONUS6-1.33 km6 hr60/36 High Resolution WindowHiRESWO/CONUS3-4 km12 hr48 Short Range Ensemble Forecast SREFN. America16 km 6 hr87 SystemAttributes RAP GSI EnKF-3DVAR hybrid, Diabatic Digital Filter w/radar data HRRR GSI 3DVAR (hybrid pending) w/15min radar data for one hour NAM and NAM nests GSI EnKF-3DVAR hybrid 12-h NAM Data Assim System w/3-h updates w/radar data HiRESW RAP for CONUS and GDAS for OCONUS SREF Initial condition diversity via RAP, NAM and GFS System Data Assimilation or Initialization Technique

3. 3 Why System(s) are Operational  Primary stakeholders and requirement drivers The weather enterprise, NWS regions & WFOs, NCEP centers, Water Center, Air Quality, broadcasting, dispersion/transport, severe/hazardous wx environment, agriculture, transportation, energy, NextGen etc  What products are the models contributing to?  NDFD forecasts, watches/warnings, outlooks, airmets/sigmets, CMAQ/HYSPLIT, reg’l wave height, NLDAS, regional ic’s & lbc’s etc  What product aspects are you trying to improve with your development plans?  QPF, sensible wx, severe wx environment via physics development  Move deterministic guidance to all ensemble based guidance suite  Consolidate old SREF, NAM, NAMRR & RAP into new SREF  Eventually transition to single-core ens. & ensDA [NGGPS]  Expansion?: domain for TCs, inline lake, aerosols, fire behavior; coupling  Top 3 System Performance Strengths Provides reliable guidance to the whole nation multiple times per day Provides both 1st look [early slot] & outlook [to 3.5 days] Hourly updates, aviation hazards, storms & storm/pre-storm environment  Top 3 System Performance Challenges Pre-convective environment, QPF biases, stable PBL, C&V, cloud decks Advancing ens. DA, scale aware physics [parent&nests] Large/diverse enough membership for new SREF to improve on GEFS

4. 4 System Evolution Over the Next 5 Years  Major forcing factors Digital Services, WxReadyNation, FACETS = need for probability guidance Increasing sat. obs GOES-R, JPSS while JCSDA solves sfc emissivity Mandate to simplify production suite while moving to ensemble guidance  Science and development priorities Probabilistic guidance across the full spectrum of wx phenomena Provide initial/lateral boundary conditions for HREF Ensemble techniques, ens. data assimilation & improved physics  What are your top challenges to evolving the system(s) to meet stakeholder requirements? Resistance to ensembles & streamlining, must be able to drop legacy stuff HPC for ens DA and ens forecasts, observational data latency and QC Leveraging selected NGGPS dynamic core and unifying regional efforts around this core once the capability is in place Resistance to unification & to development based on best science with focus on performance not “ownership”  Potential opportunities for simplification going forward Unify all regional modeling applications with HREF & SREF consolidation, eventually including rapid refesh, hurricane, fire weather, AQ etc using a single-dycore [from NGGPS?]. Single ensemble DA including aerosols and even land-surface. Retain GSI common regional/global DA extended to 4D. Unify physics with scale-aware and aerosol-aware capability Inline aerosols, fire behavior and couple to ocean, lake, wave, ice & eco across both regional and global models.

5. 5 Top 3+ Things You Need From the UMAC 1.Start with the simplest possible future operational suite (single regional model/ens/assim and single global model/ens/assim). Then, UMAC can help NOAA consider if all forecast requirements can be met by them before adding complexity. Simplicity is more plausible with a 3km global model. Similarly, given a 1km regional ensemble Expanded CONUS including all area within 48h landfall Avoid all moving nests because fixed nests support ensemble effectiveness. 2.Help with trade offs among delivery time, forecast range, update frequency, number of nests, ensemble size & member configuration choices etc 3.Guidance on how to focus/balance resources (computing & manpower) based on multitude of requirements (continental vs local, ensembles, ens. DA, NGGPS dy-core, HREF-SREF-GEFS, WOF, FACETS, etc).