Improving Nowcasting of convective storm development using MSG SEVIRI, MODIS, and GOES-12 imagery as risk reduction for GOES-R ABI
Kristopher M. Bedka, CIMSS/Univ. of Wisconsin, Madison, WI; and W. F. Feltz, J. Sieglaff, and J. R. Mecikalski
Research is being done at the University of Wisconsin-Madison's SSEC/CIMSS to evaluate the potential improvement in diagnosing and nowcasting convective storm development through the use of future GOES-R ABI imagery. As ABI may still be ~7 years from launch, aspects of current generation instruments must be combined to simulate what ABI imagery could provide. MSG SEVIRI and MODIS are being used to assess the benefits of improved spectral coverage from ABI. 1 km IR imagery from MODIS is being used to investigate benefits of ABI's improved spatial resolution. 1 (SRSO) to 5 (RSO) minute imagery from GOES-12 is being used to look at improvements in temporal resolution from ABI.
Results show that for 1-5 min resolution imagery, one can compute cloud top growth trends without having to explicitly track cumulus cloud pixels over time, as their movement is limited to a small area over such a short time period. Thus, IR brightness temperatures and differences can be combined with a convective cloud mask to compute “box-averaged” cumulus cloud properties which can be differenced in time to derive compute cloud top growth trends. This box-averaged product exhibits improved spatial coherency and fewer false alarms than the method from Mecikalski and Bedka (MWR, 2006) which uses mesoscale satellite winds to compute growth trends at the pixel scale.
Improved ABI spatial resolution and spectral coverage will allow for improved convective cloud classification and depiction of severe thunderstorm signatures such as overshooting tops and enhanced-V features. Also, information from the 8.5 and 12.0 micron channels can be used as a proxy to identify cloud-top phase transitions, an important indicator of the onset of precipitation at the surface over the mid-latitudes. Results show improved nowcasting of convective initiation from MSG SEVIRI through the use of better cumulus classification and cloud microphysical information during the COPS field experiment.
Poster Session 1, Fifth GOES Users' Confererence Poster Session
Wednesday, 23 January 2008, 2:30 PM-4:00 PM, Exhibit Hall B
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