WFO Raleigh, NC (RAH) has been collaborating with the NASA/MSFC’s Short-term Prediction Research and Transition (SPoRT) project to evaluate several unique NASA research satellite products or displays. Previously we have been evaluating the MODIS hybrid products and this fall we have begun evaluating the Night-time Microphysics RGB product from VIIRS and MODIS for use with observing fog and low clouds.
The Night-time Microphysics RGB imagery uses the common IR spectral difference for fog/low cloud detection as well as inputs related to optical thickness and the cloud’s thermal property in order to help differentiate low clouds and near-surface fog. The SPoRT folks have setup a SPoRT Real-time Data Fog and Low Cloud web page (http://weather.msfc.nasa.gov/cgi-bin/sportPublishData.pl?dataset=foglowclouds) to view the data externally. Additional explanation of this product is available in a Quick Guide on the SPoRT training page (http://weather.msfc.nasa.gov/sport/training/rgb_ntmicro/RGB%20Nighttime%20Microphysics%20Reference%20Guide.pdf).
The image below is the Night-time Microphysics RGB product from 0701 UTC 26 October 2012 across the Mid-Atlantic and Carolinas from the RAH AWIPS D2D. This image shows multiple cloud features including high clouds (in various shades of red) associated with Hurricane Sandy off the Carolina coast. An area of stratus associated with a marine layer advancing southwestward into Virginia and northeast North Carolina (noted in shades of aqua and light blue). Finally, an area of stratus clouds was noted across the southern Appalachians of western North Carolina and northeast Georgia (noted in shades of blue and tan). Some additional details on the three area of cloudiness across the region:
- The high cloud shield associated with Hurricane Sandy off the Carolina coast is shown various shades of red, indicative of very high, cold clouds.
- An area of stratus associated with a marine layer advancing southwestward into Virginia and northeast North Carolina can be seen. These clouds are largely highlighted with shades of aqua and light blue, especially away (northeast) of the leading edge of clouds. The shading of aqua and light blue is often indicative of areas of low clouds and light fog with most observations having VFR visibility, but IFR ceilings. The leading edge of these clouds, on the west and southwestern periphery, have a little but more light purple mixed in with the blue, indicative of areas with observations of fog with both low ceiling and visibilities.
- An area of stratus and fog is shown in the southern Appalachians of western North Carolina and northeast Georgia. These clouds have a tan color, indicative of higher and colder clouds which are often highlighted with shades of tan or green. The tan color (a little bit more red shading) indicates a thicker cloud while green shading would have been indicative of thinner clouds (with a little less red shading).