Assessing the Performance of the High Resolution Rapid Refresh (HRRR)'s Quantitative Precipitation Forecasts (QPFs) Over Florida During Different Sea Breeze Flow Regime Patterns

The predominant job function of the broadcast and operational meteorologist is to develop short term forecasts. Such predictions address questions regarding hourly and daily temperature, sky cover, and wind trends over a defined region or market area. Arguably some of the more popular forecast questions that meteorologists must answer include “Will it rain today and, if so, how much?”. This is particularly true for predictions over the state of Florida.

Peninsular Florida’s precipitation budget is largely influenced by sea breeze circulation. The development of this convection, and the spatial and temporal distribution of precipitation, is also influenced by mean 1000-700 mb wind flow. This low-level flow has been studied according to magnitude and direction and can be classified into distinct sea breeze wind flow regimes.

Operational and broadcast meteorologists frequently consult model data when developing their answers to daily forecast questions. This project aims to assess the performance of the High-Resolution Rapid Refresh (HRRR) when predicting sea breeze summertime precipitation accumulation over peninsular Florida. Of principal interest is the model's performance for each sea breeze regime. By binning a roughly equal number of case studies into each regime from 2019-22, we perform neighborhood and spatial verification of 15-hour accumulated rainfall from the 12Z forecast run using the MET toolkit, against Stage IV precipitation data. Through the analysis of traditional and spatial verification metrics, we hope to identify patterns in HRRR output performance, and thus evaluate the model's effectiveness in assisting meteorologists with their short term forecast development.