Future NCEP Guidance Support for Surface Transportation by qob12941


									Future NCEP Guidance Support
  for Surface Transportation

              Stephen Lord
     Director, NCEP Environmental
            Modeling Center
              26 July 2007
• Weather for Roads, Air transportation, etc.
  – National picture
     • New ensemble products
  – Local picture
     • Downscaling
        – Real-time Mesoscale Analysis (RTMA)
        – Land Information System (LIS)
        – Dynamical – Statistical approach
• Marine applications
  – Waves
  – Water levels
• Data availability
• What’s needed to move ahead
        New Ensemble Products from
        NCEP Storm Prediction Center
  • NCEP Short-Range Ensemble Forecast (SREF) System
  • National coverage ~ 30 km grid
  • Probabilistic guidance with extremes
SREF Maximum (any member)      SREF Pr[Ptype = ZR] and Mean   SREF 6h Calibrated Probability
  3h Accumulated Snowfall            P03I (contours)              of Snow/Ice Accum

                                                                Accumulation based on MADIS
                                                                   road surface condition
                         D. Bright
                        NCEP/SPC                                                          3
SREF Likely PTYPE and Mean P03I (contours)
                      24 h Fcst
                 Precip Type, Amount
                    32 F Isotherm


                                                 D. Bright


   • Future computing requirements
           – National scale ~20 years to reach sufficient resolution
   • Dynamical-statistical approach
           – Real time Mesoscale Analysis (RTMA)
           – Land Information System (LIS)
           – Bias correction and statistical processing
   • Components under development

Forecast      Current      Current      Future       Future       Other factors   Total     Years to
System        Horizontal   Vertical     Horizontal   Vertical                     Compute   Achieve at
              Resolution   Resolution   Resolution   Resolution                   Factor    current
NAM               12           60           2           100       2x physics         720        19
SREF              37           48           5           100                          844        20
         Real-Time Mesoscale Analysis
    •    5 km National (NGDG) grid (eventually 2.5 km)
    •    Hourly analysis
          – Focus on “drawing to obs” (mesonet)
          – Temperature, precipitation, surface wind, dew point
          – Anisotropic (e.g. land-water contrast)
    •    Analysis uncertainty                                                           M. Pondeca
    •    To include cloud cover                                                          J. Purser
    •    Will cover CONUS, Alaska, Hawaii, Puerto Rico, Guam                            G. DiMego
                                                                                      NOAA/GSD - RUC
RTMA Temperature Analysis (° F)   RTMA Temperature Analysis Uncertainty (° F)   RTMA 1-hour Precipitation Analysis
        (17Z 6/14/07)                          (17Z 6/14/07)                         (inches) (01z 6/14/07)

     Land Information System (NASA/NOAA)
     •    Land states forced by                                           S. Kumar
           – Observed precipitation                                       Jim Geiger
           – Model solar, long wave radiation,                         C. Peters-Lidard
             cloudiness                                                     J. Meng
     •    Noah Land Surface Model (LSM) defines                           K. Mitchell
          skin temperature, soil moisture, etc.
     •    Can be run at 1 km resolution (below)

Surface (skin) Temperature      50 km area         Washington DC    NASA LSM GFS forcing
                                    00 UTC 1 July – 21 UTC 1 July

 00 UTC                   03 UTC                    06 UTC            09 UTC
  7 PM                    10 PM                      1 AM              4 AM

 12 UTC                   15 UTC                    18 UTC            21 UTC
  7 AM                    10 AM                      1 PM              4 PM

 Dynamical Statistical Approach
• Bias correction of forecast fields with respect to model
  analysis (e.g. NAM)
• “Downscaling Transformation” (DT)
   – Produces time-dependent differences between coarse forecast
     model (e.g. 12 km NAM) and RTMA (5 km)
• Downscaled (local) fcst =
           NAM fcst + Bias correction + DT
   – On local grid
• Probabilistic products
   – Created from ensemble systems (SREF, GENS) through
     Bayesian Model Averaging (BMA) approach
   – Applications for
       • Road transportation
       • Air transportation management (NEXTGEN)                   8
       • Severe weather forecasting
                    Marine Applications
                  Multi-Grid Wave Modeling
               Higher coastal
              model resolution               Deep ocean model resolution

Highest model resolution
   in areas of special                                       Multi-grid wave model tentative
         interest                                          resolutions in minutes for the parallel
                   Hurricane nests moving                    implementation in FY2007-Q4.
                   with storm(s) like GFDL
                          and HWRF                                                              9
                                               Wave ensemble system application for ship routing
 NCEP Real-Time Ocean Forecast System (RTOFS)
 Operational December 2005, upgraded June 2007
• RTOFS provides
   – Routine estimation of the ocean
     state [T, S, U, V, W, SSH]
       • Daily 1 week forecast
   – 5 km coastal resolution
   – Initial and boundary conditions
     for local model applications
• Applications
   – Downscaling support for water levels
     for shipping                           Chesapeake Bay
   – Water quality
   – Ecosystem and biogeochemical
   – Improved hurricane forecasts
   – Improved estimation of the
     atmosphere state for global and
     regional forecasts                                      10
• Collaboration with NOAA/NOS
           Product Availability
•   Three levels of information
    – Routinely delivered
      1. Pointwise, single-valued, downscaled MLF* from
         all available guidance on NDGD grid
      2. Description of forecast uncertainty through
         probability density function (mode & 10/90 %ile)
      • Accompanying post-processed fields
         – Meteorologically consistent
         – Closest to MLF*
    – “On-demand” (via publicly accessible server)
      3. Individual ensemble member forecasts available
      • Prototype: NOMADS                               11
                                         * MLF – Most Likely Forecast
          What’s Needed?
• Written requirements for surface
  transportation to NWS
• Operational (and research) computing
• Acceleration of current dynamical-
  statistical efforts
• Outreach and coordination with local users

      Concurrent execution of global and
      regional forecast models (Phase 2)
Analysis              Global/Regional Model Domain                    Model Region 1

  •   Real time boundary and initial conditions
      available hourly                                                Model Region 2
       – “On-demand” downscaling to local applications
            • Similar to current hurricane runs but run either
                 – Centrally at OR
                 – Locally (B.C, I. C. retrieved from on-line data)
            • No boundary or initial conditions older than 1 hour
       – Flexibility for “over capacity” runs (e.g. Fire Wx, Hurricane)
            • Using climate fraction must be planned
            • No impact on remainder of services                          Local Solution

  •   For NEXTGEN: A consistent solution from global to local with a single

      forecast system and ensembles providing estimate of uncertainty

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