Parameterization of Moist Processes for Next-Generation Weather Prediction

physics interactions

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Location and Date

NOAA Center for Weather & Climate Prediction (NCWCP), College Park, Maryland January 27-29, 2015

Workshop Overview

NOAA and the Development Test Center (DTC) will convene a workshop to stimulate the development of moist process parameterization for the Next-Generation Global Prediction System (NGGPS) and similar global models. The theme of this workshop will also be highly relevant to current and future generation regional and mesoscale models. The goal of the workshop will be to inform and advise on the future directions of moist process parameterization development, with a particular emphasis on numerical weather prediction applications for scales and resolutions ranging from synoptic- to convection-permitting. The workshop will review the representation of processes in current NWS models, survey the range of conceptual and theoretical ideas emerging from modeling centers and universities, and work to develop a medium-term plan to implement and test the most promising ideas in existing and emerging NOAA global and regional forecast models. The workshop will include observational, modeling and theoretical perspectives. Specific foci will include:

  • Cloud microphysics, especially ice and mixed-phase processes, with emphasis on finding the appropriate level of complexity and numerical formulation of microphysics
  • Efficient and consistent treatments of sub-grid heterogeneity across a range of model resolutions
  • Robust treatment of uncertainties associated with physical parameterization of moist processes (stochastic physics)
  • Interactions of turbulence, radiation, shallow and deep convection, clouds and microphysics
  • Particular challenges raised by parameterizations in the simulation of high-impact events (e.g. hurricanes)

External speakers include Gilbert Brunet (CMC), Chris Bretherton (University of Washington), Richard Forbes (ECMWF), Axel Seifert (DWD), Michael Whitall (UK Met Office).

Related NGGPS Overivew

The NOAA's National Weather Service and Office of Oceanic and Atmospheric Research are embarking on an ambitious plan to develop a Next-Generation Global Prediction System (NGGPS). The model at the center of this system is expected to have a spatial resolution of roughly 10 km with the possibility of resolution varying by an order of magnitude or more - similar to mesh sizes used by current limited-area models. While increasing spatial resolution is known to benefit many aspects of forecasts, the global modeling community has relatively little experience with parameterizations at such scales and essentially no experience in developing parameterizations for grids with variable size. The NGGPS also seeks a robust treatment of model uncertainty to enable situation-specific "error bars" around each forecast element; the expectation is that uncertainty estimates will be provided directly by parameterizations wherever feasible.

The parameterization of moist processes including clouds, shallow and deep convection, microphysics, and the coupling with turbulence, is one of the toughest tasks in developing a system like the NGGPS. Clouds are intimately linked to weather through their effects on circulations and energetics and the parameterization of moist processes has historically been one of the toughest challenges for global numerical weather prediction models. This parameterization problem is perhaps most acutely difficult at 1-10 km scales since clouds and convection are neither explicitly resolved nor easily parameterized using traditional assumptions that rely on the presence of many clouds within each grid column.

The NGGPS, therefore, requires a new generation of physical parameterizations to better represent microphysics, clouds, shallow and deep convection, and interactions with turbulence and radiation. Such parameterizations will need to have greater fidelity than current methods across a range of scales and resolutions, and will allow for the representation and propagation of state-dependent uncertainty.

Contacts - Organizing Committee

  • Robert Pincus (CU) (Robert.Pincusinsert
  • James Doyle (NRL) (James.Doyleinsert
  • Yu-Tai Hu (EMC) (yu-tai.houinsert
  • Jamie Wolff (DTC) (jwolffinsert

The workshop will consist of roughly one day of presentations a) describing the current state of parameterizations in NCEP/EMC models and b) surveying promising new directions at various stages of development, followed by a day and a half of discussions aimed at providing guidance to NCEP/EMC development plans over the next five years.

Note: Due to a 2 hour delayed start for the federal government offices today, Tues 27 Jan 2015, we will begin the workshop at 1000.


Tuesday, 27 January 2015

1000 - 1015    Coffee
1015 - 1025    Welcome (Hendrik Tolman, NCEP)
1025 - 1030    Workshop goals
1030 - 1115    Keynote: Ten-year prospective for Numerical Weather Predition (Gilbert Brunet, CMC, UKMO)
1115 - 1200    Keynote: Challenges in coupling process across scales (Chris Bretherton, U. Wash)
1200 - 1300    Lunch
1300 - 1345    Convection: Survey/prospectus (supplemental)(Michael Whitall, UKMO)
1345 - 1400    Convection: EMC status (Jongil Han, EMC)
1400 - 1445    Clouds: Survey/prospectus (Richard Forbes, ECMWF)
1445 - 1500    Clouds: EMC status (Ruiyu Sun, EMC)
1500 - 1515    Break
1515 - 1600    Microphysics: Survey/prospectus (Axel Seifert, DWD)
1600 - 1615    Mirophysics: EMC status (Brad Ferrier)
1615 - 1700    Climate Process Team presentations (Chris Bretherton, U. Wash.; Steve Krueger, U. Utah; Dave Randall, CSU; Sarah Lu, SUNY-Albany)
1700 - 1715    NGGPS Overview (Fred Toepfer, NOAA)
1715 - 1730    Discussion plan for Wednesday

Wednesday, 28 January 2015

0800 - 0830    Coffee
0830 - 1000    Discussion Breakout Session 1: Foundations - Microphysics, convection, clouds & turbulence
1000 - 1030    Break
1030 - 1200    Discussion Breakout Session2: Short-term prospects: What's next?
1200 - 1315    Lunch
1315 - 1345    Plenary: Stochastic physics perspectives (Dave Randall, CSU; Judith Berner, NCAR)
1345 - 1515    Discussion Breakout Session 3: "Grey zone" & probabilistic forecasts - Non-locality/non-deterministic/uncertainty
1515 - 1530    Break
1515 - 1700    Discussion Breakout Session 4: Medium term - Priming the pump
1700 -            Working dinner and continued discussion at Franklin's Restaurant and Brewery

Thursday, 29 January 2015

0800 - 0830    Coffee
0830 - 0930    Plenary: Summaries from Breakout Sessions (Discussion leader summaries)
0930 - 1030    Plenary Discussion
1030 - 1045    Break
1045 - 1200    Next Steps and Plenary Conclusion