Stratospheric Air Intrusions and Rapid Cyclogenesis over the North Pacific: Case Studies Winter 2017-2018

Stratospheric air intrusions (SAIs) are a known catalyst for rapid intensification and explosive cyclogenesis of maritime cyclones, yet forecasters and numerical models still have trouble predicting the onset and rate of rapid intensification. This is especially true over regions of the oceans where surface observations are sparse. Forecasters at NOAA’s Ocean Prediction Center must rely primarily on satellite imagery to estimate whether a cyclone is developing explosively due to the lack of observations. This research aims to find a way to use new products from the Geostationary Operational Environmental Satellite - R-Series (GOES-R) and the Joint Polar Satellite System (JPSS) satellites to help forecasters more easily identify SAIs and therefore, anticipate and predict rapid cyclogenesis. Case studies were identified and investigated across the North Pacific during the 2017-2018 winter season using Himawari 8 products (airmass RGB, water vapor similar to GOES-R) and ozone data from EUMETSAT’s Infrared Atmospheric Sounding Interferometer (IASI) and the NOAA Unique Combined Atmospheric Processing System (NUCAPS). With each storm, characteristics of SAIs were identified, and a determination was made as to whether or not the SAI contributed to rapid intensification. During the 2018-2019 winter season, these identification methods will be tested and evaluated based on their ability to enhance the forecast capability of rapid cyclogenesis in real time.