LI and MPE

In addition to the single channels and RGB products, we can also use other derived satellite products to monitor the convection. The animation below shows the Lifted Index and Multi-Sensor Precipitation Estimate on 20 March 2016 from 0300 to 1500 UTC. View it, then answer the question below.


How do the Lifted Index and Multi-Sensor Precipitation Estimate help you evaluate the potential for convection?

The correct answers are A and E.

The expanding red and yellow areas in the LI images indicate that the airmass is generally becoming more unstable during the day. This makes option A correct and option B incorrect.

As to option C, the LI cannot be calculated for the areas in black, which are cloud masked. But we can still get useful information from the product since the cloud mask only covers part of the scene. Moreover, the areas around the masks are quite red and yellow, indicating very low LI values. This means that the clouds in those areas may have reached the convective stage. This is mainly evident during daytime.

Option D is incorrect since the MPE already shows some convective cells in the cloud mask areas in the morning. The number of cells increases during the day. The precipitation is clearly convective throughout the region.

Option F is incorrect because instability can continue for hours while convection often develops only later. We see this in the area over Uganda, Rwanda, and the eastern parts of the DRC. Between 06 and 11 UTC, the air is increasingly unstable but convection really intensifies only after 11 UTC.

Please make a selection.