Advancing Understanding of the Relationship Between Tropical Cyclogenesis and Precipitation in A High-Resolution Model
This study evaluates the relationship between tropical cyclone (TC) genesis, also known as tropical cyclogenesis, and precipitation in forecasts produced by the Basin-scale Hurricane Weather Research and Forecasting (HWRF-B) model. Pre-TC (PTC) forecasts from HWRF-B were produced during the 2017-202...
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SJSU ScholarWorks
2022
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| Online Access: | https://scholarworks.sjsu.edu/etd_theses/5340 https://doi.org/10.31979/etd.y7tx-egkb https://scholarworks.sjsu.edu/context/etd_theses/article/8887/viewcontent/Jafary_sjsu_6265M_11752.pdf |
| Summary: | This study evaluates the relationship between tropical cyclone (TC) genesis, also known as tropical cyclogenesis, and precipitation in forecasts produced by the Basin-scale Hurricane Weather Research and Forecasting (HWRF-B) model. Pre-TC (PTC) forecasts from HWRF-B were produced during the 2017-2020 hurricane seasons in the North Atlantic and eastern North Pacific. In PTC forecasts, various precipitation characteristics, including rate, and coverage, were compared for different forecast outcomes of signal detection: hits, misses, false alarms, and correct rejections. Moreover, differences in radar reflectivity, mid-tropospheric moisture, and vertical wind shear (VWS) were studied and compared for developing (i.e., underwent cyclogenesis) and non-developing PTCs. In particular, we focused on comparisons between hits and false alarms (i.e., developing PTC forecasts), as well as between misses and correct negatives (i.e., non-developing PTC forecasts), to distinguish one forecast outcome from the other. In other words, the goal is to determine if developing and non-developing PTC forecasts are accurate based on precipitation, moisture, and wind shear. The result from this study indicates that the developing cases had greater maximum precipitation rates as well as a larger area coverage of higher precipitation rates at most lead/lag times. Further, VWS results revealed that non-developing disturbances also experienced weak upper-level flow. Together, these results indicate that thermodynamic properties play an important role in determining the evolution of disturbances in the North Atlantic basin. |
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