NAEFS Forecasts for 814 Day Mean Temperatures

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NAEFS Forecasts for 8-14 Day Mean Temperatures

• Dan Collins, Jon Hoopingarner, Edward Olenic,
  David Unger
• NOAA/NWS/NCEP/CPC

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Outline

• Current 8-14 Day Product
• NAEFS product
• Calibration Procedure
• Example Forecasts
• Conclusions

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CPC operational product

• 8-14 Day Mean Temperature
• Tercile Probabilities
• Provide the probability of occurrence in the
  favored category, Below, Near, or Above Normal

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Current Product

• Issued daily at 3 PM
• Human input (weekdays), Automated
  (Weekends)
• GFS 12Z(y), 18Z(y), 00Z, 06Z
• CMC 00Z
• CDC Reforecast Model (1998 Version of the
  GFS)
• Downscaling to Surface
• Klein Specification Equations
• Analogs with past cases
• Calibrated Model Output
• Neural Net Specifications

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NAEFS Forecasts

• Expand to include All North America
• Objective procedure
• Calibrated Model Output
• (Models should be better at downscaling than
  the older CPC methods)

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NAEFS Experimental Product

• Must be comparable in skill to operational
  product
• Must be consistent with operational product
• Must exhibit reasonable temporal consistency.
  (00Z and 06Z for example)

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Calibration
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Ensemble Regression

• A regression model designed for the kernel
  smoothing methodology
• - Each member is equally likely to occur
• - Each has the same conditional error
  distribution in the event it is
• closest to the truth.
• F Forecast, sF Forecast
  Standard Deviation
• ObsObservations, sObs
  Standard Deviation of observations
• RCorrelation between individual ensemble
  members and the observations
• Rm Correlation between ensemble mean and
  observations
• a1 , a0 Regression Coefficients,
• F a0 a1 F

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Time series estimation

• Moving Average, Let X11 Be the 10-year running
  mean known on year 11. N10
• X11 1/N(x1x2x3x4x5x6x7x9x9x10)
• X12 X11 1/N(x11-x1)
• XY1 XY 1/N(xY1-xY-10)
• Exponential Moving Average, a 1/N
• X12 X11 a(x11- X11)
• XY1 (1- a)XY axY1

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Adaptive Ensemble Regression
EMA estimates

• F
• F2
• (Obs)
• (Obs)2
• F (Obs)
• Fm2
• (F-Fm)2

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NAEFS 8-14 day TemperatureIssued 30 Oct. 2006
Valid Nov 7-13, 2006 Washington DC 38N 77W
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NAEFS 8-14 day TemperatureIssued 30 Oct. 2006
Valid Nov 7-13, 2006 Alaska 68N 150W
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NCEP GFS CMC
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NCEP GFS CMC
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NAEFS
Official
Observations
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NCEP GFS CMC
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NAEFS Calibrated Temperatures
Official Forecast
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Work to be done

• Implement calibration algorithms
• Smoothing/terrain corrections
• Develop a strategy for consistency with
  operational product.
• Design Probability of Exceedence (PoE) forecast
  format.