IHOP Retro Microphysics studies

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IHOP Retro - Microphysics studies

• Bulk scheme hydrometeor size distribution
  sensitivity studies

• Rain
• generalized gamma distribution N(D) N0 Dm e-lD
• shape factor, ?????????
• maximum median volume diameter 2 or 3 mm
• impacts of these changes to cold pool strength
  and propagation speed
• Graupel
• maximum/minimum y-intercept parameter 1.E6 to
  1.E4
• impact to trailing stratiform region (and more?)

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Idealized 2D real 3D cases

• WRF squall2d_x
• sensitivity tests with distribution
  characteristics
• comparison of Thompson (single-moment) vs.
  Seifert, Morrison (two-moment) bulk schemes
• potential for comparison with Geresdi bin
  microphysics scheme
• 3D cases
• 12-13 May 2005 (KOUN polarized disdrometer)
• 12-13 Jun 2002 (IHOP)
• other IHOP cases, potential BAMEX cases,

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Squall2d_x 5-hour forecast
CONTROL (mvd_r3mm)
Max rain mvdlt2mm
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12-13 May 2005 IHOP cases
Grids with spacing 20, 5, and 1 km
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12-13 May 2005 (OKC squall line)
13-h forecast valid 0100 UTC 13 May
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Comparisons to observations

• Microphysics
• S-Pol hydrometeor classification (especially
  hail)
• melting layer height/thickness
• hydrometeor size distribution characteristics
• General
• rain rates, total precip
• radar reflectivity
• storm structure
• cold pool strength and propagation speed