An Analysis of the Extratropical Transition of Hurricane Arthur (2014) from a JPSS Proving Ground Perspective

Hurricane Arthur (2014) was an early season hurricane that had its roots in a convective complex in the Southern Plains of the U.S. As the complex moved into northern Texas, a Mesoscale Convective Vortex (MCV) formed and drifted east, eventually moving off the coast of South Carolina. The MCV drifted south and slowly acquired tropical characteristics, eventually becoming a Category 2 hurricane that would affect much of eastern North Carolina prior to the 4th of July holiday weekend. Arthur continued up the coast, brushing portions of southeast New England as it interacted with an upper-level trough and began undergoing extratropical transition. The storm became an extratropical cyclone over the Canadian Maritimes, bringing damaging gale force winds and heavy rain to the region.

As part of the GOES-R and JPSS Satellite Proving Grounds, multiple proxy and operational products were available to analyze and forecast this complex evolution. The National Hurricane Center, Ocean Prediction Center, Weather Prediction Center, and NESDIS Satellite Analysis Branch were able to monitor the tropical and extratropical transition of Arthur (2014) using various convective and red, green, blue (RGB) products that have been introduced in recent years. During the extratropical transition, the Air Mass RGB product and AIRS/CrIS ozone products were available as a compliment to water vapor imagery to identify the upper-level low with associated stratospheric drying that absorbed much of Arthur's energy. These extreme events often occur over the ocean in data sparse regions, therefore satellite-based proxy products provide forecasters with more information when forecasting complex events. The Air Mass RGB product provides forecasters with an enhanced view of various air masses that are combined into a single image and can help differentiate between possible stratospheric/tropospheric interactions, moist tropical air masses, and cool, continental/maritime air masses. Even though this product provides a wealth of qualitative information about the horizontal distribution of synoptic features such as atmospheric conveyor belts, jet streaks, and potential vorticity anomalies, forecasters are also interested in more quantitative information such as the vertical distribution of temperature, moisture, and ozone which impact the coloring of the resulting Air Mass RGB.

Currently, NOAA Unique CrIS/ATMS Processing System (NUCAPS) temperature and moisture soundings are available in AWIPS-II as a point-based display. Traditionally, soundings are used to anticipate and forecast severe convection, however unique and valuable information can be gained from soundings for other forecasting applications, such as extratropical transition, especially in data sparse regions. Additional research has been conducted to look at how JPSS CrIS/ATMS NUCAPS soundings might help forecasters identify the pre-extratropical transition environment, leading to earlier diagnosis and better public advisories. CrIS/ATMS NUCAPS soundings, AIRS soundings, NOAA G-IV GPS dropwindsondes, and the Air Mass RGB were analyzed leading up to and during Arthur's tropical to extratropical transition. The presentation will focus on the use of CrIS/ATMS NUCAPS in concert with the Air Mass RGB product to analyze Arthur's extratropical transition for use in NWS operations.