SREF Applications at AWC

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SREF Applications at AWC

• Dr. Steverino Silberberg
• Aviation Weather Center
• October 31, 2006
• NCEP Ensemble Users Workshop

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AWC-EMC Collaboration

• Aviation-specific SREF guidance
• Binbin Zhou, Jun Du, Jeff McQueen
• probabilistic guidance for aviation weather
  forecasts
• experimental

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Aviation SREF Methodology

• Generate aviation-related diagnostics variables
  in common post (ETA, WRF, RSM)
• Produce ensemble products in SREF post
• Graphics on Aviation-SREF website

4
Aviation SREF Algorithms

• AWC-developed
• Externally-developed
• RUC-based deterministic guidance e.g. icing
  (CIP, FIP), turb (GTG), etc.
• AWC-EMC collaboration during assimilation of
  algorithms into SREF operations

5
Aviation SREF Feedback

• Reduce/access/calibrate uncertainty
• Reduce/represent model error
• Provide distribution characteristics, etc.

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Aviation SREF Feedback

• New products
• Algorithm enhancements, changes
• One-hour output F00-F24
• Add global ensemble
• Add to SREF ops on CCS GEMPAK data flow

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Aviation SREF Feedback

• Application to AWC production products
• FAA requires deterministic aviation forecast
  products except for probabilistic collaborative
  convective forecast product (CCFP)

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Aviation SREF Verification/Validation

• Is truth out there?
• If a tree falls in a forest
• PIREPS ? difficult to use
• NCEP FVS works for regular weather not for
  aviation weather
• low level wind shear has been verified in FVS
• adapt FVS to aviation
• Collaborate with RTVS for aviation
  verification/validation

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SREF Aviation Product List
Variables Products Levels/Regions Algorithms
Icing Prob of occurrence (100s of ft) 240,180,150,120,090,060,030,000 T-RH-Vertical drift Cloud water/ ice/snow
Clear air turbulence (CAT) Prob of occurrence (LGT,MDT,SVR) (100s of ft) 420,390,360,330,300,270,240,210 Ellrod 1992
Cloud Mean/spread Prob of ovc,bkn,sct,clr Ceiling, cloud base Model-output
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SREF Aviation Product List
Variables Products Levels/Regions Algorithms
Visibility Mean/spread Surface Stoelinga 1999
Ceiling Mean/spread Ceiling, cloud base Conditional
Flight-Restriction Prob of LIFR,IFR,MVFR,VFR Vis and/or Ceiling Visibility-ceiling
Jet-stream Prob of gt 60,80,100 kt 45,180,340 (100s of ft.) Model-output
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SREF Aviation Product List
Variables Products Levels/Regions Algorithms
10m-wind speed Mean/spread Prob of gt 10,20,30 kt 10m Model-output
Convective cloud Mean/spread/ directions Grid convective cloud
Low level wind shear (LLWS) Mean/spread Prob of severe (20 kt/2000 ft) Wind vector difference
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SREF Aviation Product List
Variables Products Levels/Regions Algorithms
Tropopause Mean/spread Model-output
Freezing-level Mean/spread Sfc, 4, 8, 12, 16 (kft) Model-output
Fog Prob of occurrence Surface Cloud base/top threshold
Mountain obscuration (to be added) Prob of occurrence Mountains RH 80, 90 Cloud water/ ice/snow
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Summary

• AWC-EMC collaboration
• Robust aviation-specific SREF guidance
• Verification/validation work difficult, required
• NAWIPS SREF tools developed by SIB
• Web?NAWIPS path to AWC operations
• Add aviation-specific SREF guidance to SREF ops
  on CCS GEMPAK data flow ? NAWIPS
• Collaboration with NCEP centers
• NCO SIB
• Convective fields (SPCs David Bright)