Analysis of Multi-source Meteorological Data on"2.13"Heavy Snowfall Process in Central Hebei in 2022
Using conventional observation data,era5 reanalysis data,wind profile radar products,ground-based GPS/MET and precipitable water vapor(PWV),the process of heavy snowfall in Central Hebei on February 13,2022 was analyzed in detail.The results showed that within 36 h before snowfall,PWV showed an increasing trend,with the fastest increase from 0 to 12 h and a slow increase from 12 to 36 h.There was a positive correlation between precipitation and PWV,and the change of PWV was stable during snowfall.With the continuous decline of PWV,the precipitation ended.The evolution of horizontal wind direction and wind speed of wind profile radar had certain indication significance for snowfall forecast.The southwest low-level jet of 20 m/s suddenly appeared at 3 000 m,and the snowfall increases as the southwest low-level jet of 20 m/s extended downward to a height of 2 500 m.Before the snowfall,the positive velocity of 0.5 m/s and above first appeared above 1 500 m.When the positive velocity of 1.0 m/s or above suddenly appeared below 2 000 m,the snowfall will occurred within 0-3 h.When the vertical velocity below 1 000 m increased to 1.5 m/s and above,the snowfall intensified.The C2n value was stable from-180 dB to-165 dB during snowfall.The C2n value was less than-180 dB,the maximum detection height dropped below 3 500 m,and the vertical velocity of the whole layer was less than 0.5 m/s,indicating the end of snowfall.
wind profile radarprecipitable water vaporheavy snowlow-level jet
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