Innovations Over the Past Decade Enhancing the NOAA WP-3D and Gulfstream G-IV Aircraft

In August of 2005, the NOAA Aircraft Operations Center (AOC) flew 10 missions in support of research and operational tasking related to Hurricane Katrina. These included 6 Synoptic Surveillance missions flown by the Gulfstream G-IV and 4 Reconnaissance flights with N43RF, one of the WP-3D Orions.

Data from the 164 dropsondes released during those six G-IV missions were assimilated into operational numerical models and proved vital in NHC Advisory forecast track adjustments. In particular, a 150 nautical mile westward track adjustment was made at 5 PM EDT on the afternoon of Friday 26 August. This shifted projected landfall on Monday morning 29 August from the Florida Panhandle near Destin to the Mississippi Coast. A further westward adjustment was made on the following advisory cycle, issued at 11 PM EDT, that projected initial landfall on the Mississippi River Delta of the southeastern Louisiana Coast, followed by a final landfall on the Mainland along the LA/MS border. This effectively provided coastal residents with a greater than 54 hour lead time of a nearly perfect track forecast.

By 2005, more than two decades of research and development of the Stepped Frequency Microwave Radiometer (SFMR) at AOC had come to fruition with a fully operational tool available to both the NOAA WP-3D and the AFRES WC-130J. SFMR measurements of the abnormally expansive surface wind envelope of Katrina proved essential in NHC Forecaster's drafting of advisory wind radii estimates.

Over the past ten years since Katrina, a number of new airborne capabilities have emerged that now provide additional tools to forecasters, particularly in the arena of tropical cyclone intensity forecasting. The Tail Doppler Radar (TDR) has provided very high resolution vertical cross sections of reflectivity and radial velocities for research purposes for nearly four decades. With the availability of modern broadband SATCOM, huge data packets of TDR "Superobs" are now being transmitted off the Orion in real time to the NCEP Environmental Modeling Center for ingestion and initialization of operational runs of the HWRF.

In addition to the WP-3D TDR Superobs, similar operational data is now flowing to EMC from the G-IV Tail Doppler Radar. Operating at 13.5 kilometer altitudes, the G-IV TDR flies at approximately twice the speed of the Orion, thereby scanning much larger portions of a tropical cyclone during a given time interval. The G-IV also now carries the SFMR. When G-IV SFMR becomes fully operational, this will provide forecasters with surface wind measurements at distances well beyond the nominal 105 nautical mile legs from the storm center flown utilizing the WC-130J Alpha Pattern or the Orion rotating Figure 4 Pattern. In large cyclones, the extent of 50 knot winds and gale force winds is often beyond these standard low altitude reconnaissance flight profiles.

Introduction of the Wide Swath Radar Altimeter (WSRA) onto the WP-3D provides the capability to measure ocean directional wave spectra and significant wave heights as well as the mean square slope of the ocean surface. These data are fed directly to Miami for use in compiling NHC, TAFB and OPC wave height forecasts as well as in creation of coastal storm surge predictions. The WSRA should prove especially valuable in future storms like Katrina that generate unusually large envelopes of high waves and thereby abnormally dangerous storm surge conditions upon landfall.

During the 2014 Atlantic Hurricane Season, the first Unmanned Aerial System (UAS) was successfully launched from an aircraft into a hurricane. Multiple Coyote UAS were deployed from Orion N42RF into Category 3 Hurricane Edouard where they flew for up to 68 minutes in the eye and eyewall (recording winds of up to 100 knots in the boundary layer prior to splashdown) as well as outlying feeder bands. Controlled by an operator aboard the WP-3D, the Coyote recorded high resolution thermodynamic, pressure and wind data via two-way data link.

Other recent innovations will also be discussed. These include the real time transmission of detailed imagery from the Lower Fuselage Radar to NHC Forecasters

(utilizing the new RVP-8 radar processing and display software) as well as the introduction of an infrared sensor to dropsondes that allows for sea skin temperature measurement (augmenting the existing capability of AXBTs to map SSTs underneath and surrounding tropical cyclones).