A probability forecasting method for Ningbo strong convection weather in peripheral circulation of typhoon in Fujian

Abstract

The invention discloses a probability forecasting method for Ningbo strong convection weather in peripheral circulation of a typhoon logged in Fujian. The method comprises the following steps of: judging whether each grid point in a Ningbo region (121-122 DEG E, 28.5-30.5 DEG N) of a typhoon center at each forecasting moment in a place range performs probability forecasting of strong convection weather and calculates an occurrence probability; any grid point, when the grid points are located at the edge of the typhoon cyclonic ring current and within the range of 115-125 DEG E on 700 hPa and 500 hPa, the average wind speed of longitude wind is converted into a positive value from low latitude to high latitude according to the average wind speed of latitude; when the vertical shear factor of the wind direction of the middle and low layers of the grid points is greater than or equal to 0.5, calculating the vertical shear factor of the vector of the middle and low layers of wind, high-layer western wind torrent, high-layer radiation, low-layer typhoon inverted grooves and low-layer radiation factors of the grid points, and taking the average value of the six forecasting factors as theoccurrence probability of strong convection weather; the method has the advantages that forecasting criteria are clear, subjective forecasting factors can be objective, and forecasting accuracy can be improved.

Description

technical field [0001] The invention relates to a weather forecast technology, in particular to a probabilistic forecast method for strong convective weather in Ningbo in the peripheral circulation of a typhoon landing in Fujian. Background technique [0002] Generally speaking, the formation of strong convective weather is closely related to the three basic conditions of thermal instability, dynamic uplift and water vapor, and vertical wind shear is an important factor for the formation and maintenance of strong convective weather. Typhoons (here refers to tropical storms and above-level tropical cyclones) are deep tropical weather systems, which carry abundant water vapor and huge energy, and often bring regional heavy precipitation, and typhoons often have mesocyclones, Strong convective weather such as tornado. In addition to the combination of the typhoon's periphery and cold air, thermal instability in typhoon strong convective weather is not as obvious as in general ...

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Problems solved by technology

[0003] At present, the research on severe convective weather of typhoon is mostly based on the analysis of individual weather cases from radar data. However, there are not many synoptic-scale background analyzes and summaries of the strong convection in the Ningbo area in the peripheral circulation of the typhoon that landed in Fujian, especially there is no effective forecast method for this type of typhoon strong convection weather

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