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This conference call on October 10, 2012, discussed updates on the NDFD Questionnaire, Holland et al. (2010) model verification, NHC guidance, Irene (2011) sensitivity analysis, and future plans for CIMMSE November meeting.
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TC Winds Conference Call Wednesday, October 10, 2012 11:00 AM
Agenda • NDFD Questionnaire Update • Holland et al. (2010) model verification
Google Docs Form • Link to Form • Ways to get message out/get responses? • Only one response thus far • Dates/deadlines
Holland et al. 2010: Verification • Focused on case study with Irene (2011): all approaches of verification • Sensitivity analysis • Differences in radial wind field for each quadrant at various times • Comparisons to H*Wind analyses • Any other approaches?
NHC Guidance • Chris Landsea at NHC conducted a survey of hurricane specialists on estimates of analysis uncertainty for best track parameters of US landfall events • Tropical Storms • 34 kt: 24.1 n mi • 50 kt: 16.6 n mi • 64 kt: N/A • Cat 1-2 Hurricanes • 34 kt: 23.8 n mi • 50 kt: 19.3 n mi • 64 kt: 12.9 n mi • Major Hurricanes • 34 kt: 24.5 n mi • 50 kt: 19.1 n mi • 64 kt: 13.4 n mi
Holland et al. 2010: Sensitivity Verification • 34, 50, and 64 knot advisory radii were modified, based on error estimates • Error estimate added and subtracted from the advisory radii • Interpolated wind speed from Holland et al. model was compared to modified Rankine vortex interpolated wind speed at various distances from the storm center in quadrant one for Irene (2011) at various times
Irene (2011): Sensitivity AnalysisRange of Wind Speeds (knots)
Example Plot: Irene (2011)2100 UTC 25 August • TCM Data: Max winds: 100 KT 64 KT: 70NE 60SE 25SW 50NW.50 KT: 110NE 100SE 50SW 75NW.34 KT: 250NE 200SE 125SW 160NW. Holland et al. wind speeds lower everywhere in the quadrant (Quadrant 1 Cross Section)
Comparison to H*Wind Analyses • Important to verify against observations • Six hourly H*Wind analyses were obtained for Irene (2011) 09/23/0130 UTC – 09/27/1930 UTC • Six hourly TCM best track data obtained to interpolate wind speeds through 34 knot maximum wind radii in each quadrant • Difference fields calculated
(Central SLP 950 hPa) (Central SLP 945 hPa)
Interpolation Method Improvement • So far, shown reduced sensitivity to maximum wind radii and “smoother” wind field • Examine other storms with more “normal” pressure-wind relations • Irene (2011) 09/26/0600 UTC: 90 knot maximum sustained winds, 942 hPa central pressure • Reproduce results in paper for Iris (1995), Opal (1995), Georges (1998), Mitch (1998) (reconnaissance data) • Perhaps allow forecaster to select which interpolation method to use, based on storm structure
CIMMSE November Meeting • Date/times set? • Would like to email slides to collaborators for review before presentation • Deliverables presentation from collaborators?
Focuses Next Month • Incorporate NDFD verification into the paper (need forecaster input) • Climatology paper, hopefully get to collaborators for review • Extend H*Wind comparison to other storms (more “normal” pressure/wind relations) • Perhaps different interpolation based on storm structure • Post images to web for review of collaborators • Interpolation Improvement Summary Report • Next conference call: Wednesday, November 14th, 11:00 AM (perhaps change based on CIMMSE meeting?)