Satellite Liaison Blog

The last 24 hours has been quite interesting for residents along the Gulf Coast as a long-lived Mesoscale Convective Complex (MCC) traversed the region, seemingly reinventing itself through propagation and regeneration of the mesoscale convective vortex (MCV) at various points.  The storms dropped very impressive 1-3″ rainfall amounts in an hour or less and produced winds in excess of 70 mph in parts of Louisiana, including a gust to 68 mph in Baton Rouge.  Aided by a shortwave disturbance that ejected out of Northern Mexico/New Mexico early yesterday, this system continues moving east towards the GA/SC coast as new convection has flared up behind it off of LA, MS, and AL with a new MCV south of Mobile, AL that is helping to maintain the new system.

I put together an infrared animation of the MCC evolution starting at the TX coastline and ending this morning.  I also put together an infrared and lightning density animation to emphasize the incredible amount of lightning that has been produced by these two complexes.

GOES-13 Infrared animation showing the MCC evolution overnight along the Gulf Coast starting 1815 UTC on 05/19/16 and ending at 1430 UTC on 05/20/16.

GOES-13 Infrared and GLD-360 15-min accumulated lightning density for the Gulf Coast MCC valid the same times as the previous animation.

Meanwhile, in the Indian Ocean (Bay of Bengal region), Tropical Storm Roanu has been wreaking much havoc from Sri Lanka to eastern India with copious amounts of rainfall and gusty winds.  The tropical storm is experiencing shear today and racing towards Bangladesh, which hopefully will limit significant flooding concerns for that country.  Winds are estimated to have topped out around 50 kts (58 mph), but the bursts of deep thunderstorms have been quite impressive.

I thought we could take two different perspectives on Roanu, one from Meteosat-7 and the other from the new Himawari-8.  When looking at the animations below, notice the difference in detail between Himawari-8 and Meteosat-7 (2 km vs. 5 km and 10 min vs. 30 min, respectively).  Also, notice there is a difference in projection (especially to the west of India).  Do you know why this is happening?

Meteosat-7 11p5 µm infrared animation showing Tropical Storm Roanu affecting Sri Lanka and eastern India from 5/16/16 – 5/20/16.

Himawari-8 11.2 µm infrared animation similar to the Meteosat-7 imagery above, but at 2 km spatial resolution (closer to 4 km at this angle) and 10 minute increments.

The answer to the above question is parallax.  The imagery looks skewed due to the viewing angle in relation to where the satellite center point is located (~141ºE, 0º) compared with Meteosat-7 (~58ºE, 0º) and the projection (a form of rectilinear), but the details are still quite impressive for Roanu.

I hope you enjoyed this post.  Thanks for reading!