Real-time WRF EnKF

1
Real-time WRF EnKF

• 36km outer domain/4km nested domain

D2 (4km)
D1 (36km)
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Real-time WRF EnKF

• 3-hr update cycle for both domains (runs 8 times
  daily)
• Digital filter initialization performed on both
  domains (reduces noise)
• Bias removal on 4km domain
• Analysis and hourly forecast output saved on both
  domains (analysis,1,2,3-hr forecast)
• 80 members on 36km, 42 members on 4km

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Real-time WRF EnKF

• 3000 surface observations available for
  assimilation on 4-km domain (75 of all
  observations after terrain check)
• 1500 observations assimilated, 1500 for
  verification
• Assimilation of radiosonde, cloud-track wind, and
  ACARS data still occurs on both domains

Terrain Height (m)
36-km
4-km
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Real-time WRF EnKF

• Runtime for full 36km/4km 3-hr cycle 258
• Improvements in near future (month)
• 1) Surface background variance inflation
• 2) Faster processors
• 3) Reduced latency
• 3) Real-time graphics on web
• Analysis and forecast verification with GFS, NAM,
  RUC, 4km GFS-WRF coming soon!

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Real-time WRF EnKF

• Very early results (before bias removal)
• Analysis RMS errors against unassimilated
  observations
• 4km GFS-WRF 4km WRF
  EnKF
• Sfc Temperature 2.84 K
  2.34 K
• Sfc Wind 2.03 m/s
  2.02 m/s
• As was the case with the 12km runs, bias
  removal and variance inflation is expected to
  further improve analyses

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Real-time WRF EnKF
36km Mean
4km Mean
Near-surface Windspeed, MSLP
ANALYSIS
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Real-time WRF EnKF
36km Mean
4km Mean
Near-surface Windspeed, MSLP
01-HR
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Real-time WRF EnKF
36km Mean
4km Mean
Near-surface Windspeed, MSLP
02-HR
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Real-time WRF EnKF
36km Mean
4km Mean
Near-surface Windspeed, MSLP
03-HR
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Real-time WRF EnKF
36km Mean
4km Mean
850-hPa Temperature, GPH, Winds
ANALYSIS
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Real-time WRF EnKF
36km Mean
4km Mean
850-hPa Temperature, GPH, Winds
01-HR
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Real-time WRF EnKF
36km Mean
4km Mean
850-hPa Temperature, GPH, Winds
02-HR
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Real-time WRF EnKF
36km Mean
4km Mean
850-hPa Temperature, GPH, Winds
03-HR
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Real-time WRF EnKF
36km Spread
4km Spread
850-hPa Temperature
ANALYSIS
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Real-time WRF EnKF
36km Spread
4km Spread
850-hPa Temperature
01-HR
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Real-time WRF EnKF
36km Spread
4km Spread
850-hPa Temperature
02-HR
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Real-time WRF EnKF
36km Spread
4km Spread
850-hPa Temperature
03-HR