Short Range Forecasts of Convective Destabilization Using Information from the Advanced Himawari Imager

A relatively simple short-range forecast model has been developed at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) that uses information from the current operational GOES sounders to generate 6-9 hour "Near-Casts" of atmospheric moisture and stability indices. The system has been tested for the past 5 years using retrievals of equivalent potential temperature (thetaE) from the GOES East and GOES West sounders and has been demonstrated at the Storm Prediction Center's Hazardous Weather Testbed. Products generated by the Near-Cast model have shown skill at identifying areas of rapidly developing, convective destabilization, along with areas of stabilization, up to 9 hours in advance. It helps fill the information gap which exists between radar nowcasts and longer-range numerical forecasts. The system must be able to detect and track extreme variations in the atmosphere (especially moisture fields) at high spatial and temporal resolutions and incorporate large volumes of high-resolution asynoptic data while remaining computationally efficient to facilitate a rapid response. These requirements can best be met by observing instruments deployed on geostationary platforms.

The follow-on for the current GOES series, GOES-R, is scheduled to be launched in the fall of 2016. A separate multi-channel IR sounder will not be onboard. It will have a 16-channel imager known as the Advance Baseline Imager (ABI). The ABI will eliminate many of the limitations of the current GOES imager with improved resolution, additional scanning configurations and the elimination of periodic outages, but it will have 2 fewer spectral bands and no CO2 sensitive bands like those on the current sounder. The question remains: Can retrievals from the ABI match, or even exceed, the accuracy produced by the current GOES sounder and can they be used to near-cast significant convective development?

On 7 October, 2014 the Japanese Meteorological Agency launched Himawari-8 with a new payload called the Advanced Himawari Imager (AHI), which is nearly identical to the GOES ABI. At present, scientists at CIMSS are using the GOES sounder retrieval algorithm to generate retrieved parameters using radiances from AHI. Moisture products and stability indices are being derived from these retrievals and inserted into the CIMSS Near-Cast Model covering a domain in the Western Pacific. It is our intention to show that AHI can provide the information needed to identify and track areas of convective development.