The 1997-98 El Nino still stands out. So does a weird upward blip in UAH in January 2013. And, as Layzej conjectured, UAH LT does tend to have higher peaks than GISS during El Ninos (though not this year), and deeper drops during La Ninas.
Finally, since LT temperatures typically lag GISS by a few (?) months, I plotted the difference between UAH_LT_detrended_with_a_3-month_lag and GISS_detrended: