Systems That Produce Heavy Snow

• Intense, well-defined cyclones (High Plains cyclogenesis; East coast "bombs")
  - Deepening surface feature/closed upper low
  - Handled well by NCEP models

• Weaker, ill-defined systems (NW flow; SW flow; orographic)
  - Upper level forcing (often no surface feature)
  - Handled poorly by NCEP models

Satellite Interpretation Techniques for Heavy Snow

• Beckman, 1987 - southern edge of cold cloud top enhancement region defines southern edge of heavy snow band

• Morrison, 1989 - midpoint of coldest cloud top region defines northern extent of heavy snow band

• Johnston, 1995 - heavy snow to left of upper level cyclonic shear zone; vorticity lobe/dry slot bulge axis defines future orientation of heavy snow band

• Techniques utilize enhanced GOES IR channel 4 and IR channnel 3 (water vapor) imagery

References

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