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SREF Applications at AWC. Dr. Steverino Silberberg Aviation Weather Center May 13, 2008 4 th Ensemble Users Workshop. Aviation SREF Algorithms. AWC- developed Externally-developed RUC-based deterministic/ensemble guidance icing (CIP, FIP), turb (GTG), RUC conv prob Collaboration
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SREF Applications at AWC Dr. Steverino Silberberg Aviation Weather Center May 13, 2008 4th Ensemble Users Workshop
Aviation SREF Algorithms • AWC-developed • Externally-developed • RUC-based deterministic/ensemble guidance • icing (CIP, FIP), turb (GTG), RUC conv prob • Collaboration • AWC-EMC (Binbin Zhou, Jun Du) • AWC-SPC (David Bright) • AWC-GSD (RUCsters: Stan Benjamin, Steve Weygandt)
Aviation-Specific SREF Guidance • Flight Restriction (Ceiling/Visibility) • Ceiling (4500’, 3000’, 2000’, 1000’, 500’, <500’, mean, cloud top) • Visibility (5, 3, 1, 0.5 st mi) • VFR (>3000’ and > 5 st mi) • MVFR (1000’<ceiling3000’; 3 vis5 st mi) • IFR (500’ceiling<1000’; 1vis<3 st mi) • LIFR (<500’ and/or <1 st mi)
Aviation-Specific SREF Guidance • Cloud Amount • Total mean • Max mean • Min mean • Clear prob • Scattered prob • Broken prob • Overcast prob
Aviation-Specific SREF Guidance • 10 m wind • Speed & direction mean • > 10, 20, 30 kt prob • Low-level wind shear (lowest 2000’ agl) • Sfc – 2000’ mean • Severe prob
Aviation-Specific SREF Guidance • Convective Cloud • Mean and spread • Severe prob • RUC Convective Probability • Jet Stream • 4500’; 18,000’; 34,000’ • Icing Probability • FL000, 030, 060, 090, 120, 150, 180, 240
Aviation-Specific SREF Guidance • Turbulence probability • Light-moderate, moderate, severe • FL180 - 420 • Tropopause height/temp • Freezing level height • Precipitation type • Fog occurrence
Aviation SREF Dataflow • NAWIPS: • Individual ensemble members only • Would like Aviation SREF fields added to mean, prob, and spread GEMPAK files for NAWIPS
Aviation SREF Feedback • Reduce/access/calibrate uncertainty • Reduce/represent model error • Provide distribution characteristics, etc. • Algorithm enhancements, changes • Hourly output F00-F24 • Add aviation-specific guidance to global ensemble • Add mountain obscuration guidance
Aviation SREF Feedback • Application to AWC production & products • FAA requires deterministic aviation forecast products – except for probabilistic collaborative convective forecast product (CCFP)
Aviation SREF Verification/Validation • Verification/Validation is difficult • PIREPS difficult to use for turb, icing • 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
Summary • Robust aviation-specific SREF guidance • SREF used primarily for Cb forecasts • FAA requires deterministic forecasts • Add aviation SREF fields to mean, spread, prob files in GEMPAK • Need to calibrate aviation SREF fields, represent model error • Excellent collaboration between AWC and EMC, SPC, and RUC • Verification/validation issue: • Difficult using PIREPs • Collaboration between FVS and RTVS for verification/validation