Tornado Alley (PROG)

[F6]

fuagf -- the top one shows actual SSTs (sea surface temps); the second one shows variations from average -- that area of yellow into orange stretching west from the equatorial west coast of South America is the very non-trivial signature of an emergent El Nino -- the above-average SSTs don't have to be skying into the dark red to matter -- even in a mature El Nino most of the sea surface area within the El Nino can be and typically is within 2C above average SST -- as is the case throughout virtually all of the emergent El Nino at this point

and on the radars, decibels just means a stronger signal bounced back, a 'brighter' reflection indicating a denser target bouncing/reflecting the signal back (the highest reflectivities/decibel values reflected back by very large hail, and also in particular by debris aloft in a tornado, the 'debris ball') -- think louder return 'pings' from sonar