Diagnostic Analysis of the Causes for Heavy Snowfall Belt Southward in Zhejiang on January 20th, 2011
Abstract：This paper uses automatic station data, Micaps data, radar wind profiler data and 6 h intervals NCEP 1° ×1 ° reanalysis data to analyze and diagnose the causes for snowfall belt southward of Zhejiang on 20th January, 2011. Results show that high-level trough and low-level wind shear with the infiltration of cold air near ground provide the favorable weather scale background which heavy snow occurred to. Heavy snowfall occurred in the water vapor flux divergence convergence zone which on the left of the low-southwestern jet and jet stream southward ahead of the snowfall belt southward. The 700 hPa wind convergence line position with the leading edge of snowfall belt are in good agreement. The develop- ment and movement of moist potential vorticity baroclinic term is in good relationship with snowfall belt southward. South stretch of 850 hPa cold advection and strong warm advection between 800 hPa to 600 hPa promote the snowfall belt southward. Radar wind profiles indicated low-level cold advection began several hours earlier than the single station snowfall. Low-level cold advection can indicate the site ten〉 perature change and snowfall belt southward in advance, so it could be used as a one of the reference that can indicate the conversion of the nature of precipitation in other similar snowfall processes.
Keywords：heavy snowfallsouthwest jettemperature advectionmoist potential vorticitywind profile
Publication Date：2011-08-08
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 52-58 )