CIMSS Satellite Blog

GOES-16 ABI Band 2 (0.64 µm) and Clear-Sky Lifted Index at 1730 UTC on 6 March 2019 (Click to enlarge)

The toggle above compares a CONUS Sector visible image (0.64 µm) over the Caribbean (at 1732 UTC) with a 1730 UTC Full Disk Legacy Atmospheric Profile (LAP) Derived Stability Lifted Index field.  (A “Veggie” Band 03 0.86 µm image, here, means that coastlines need not be drawn in because of the outstanding land/sea contrast at the wavelength).  The LAP Derived Stability Lifted Index shows modestly stable air southwest of the island of Jamaica;  the blue enhancement suggests positive lifted indices (stable air) vs. the yellow regions north and south where values range from -1 to -2.  Visible imagery over the stable region does show fewer clouds than to the north and south.  Does that help you believe the small variations in stability?

GOES-16 Legacy Atmospheric Profile Derived Lifted Index at 1730 UTC along with NUCAPS Sounding Locations, ~1730 UTC on 6 March 2019 (Click to enlarge)

Suomi NPP Overflew the region shortly before 1800 UTC, and NUCAPS soundings that are produced using data from the CrIS (Cross-Track Infared Sounder) and ATMS (Advanced Technology Microwave Sounder) on Suomi NPP are available at the points shown above. Points indicated in green show where both the Infrared and Microwave retrievals successfully completed, and the animation below shows NUCAPS Soundings (at 18.66ºN, 18.20ºN, 17.74ºN, 17.28ºN, 16.82ºN and 16.36ºN) that bisect the region diagnosed as stable by the LAP Lifted Index.  Note that the NUCAPS sounding with the smallest MU Parcel CAPE, at 17.28ºN, is in the middle of the GOES-16-diagnosed stable region.

NUCAPS Soundings over the Caribbean, location as indicated by the large Purple dot. Most Unstable Parcel CAPE is noted (and also available in the nSharp readout)

from CIMSS Satellite Blog http://cimss.ssec.wisc.edu/goes/blog/archives/32233