CFSv2 Seasonal SSTs (clim19822010)
first  rec: avg(lastbs-1, lastobs, CFSv2 month 1)
second rec: avg(lastbs, cfs month 1, CFSv2 month 2)
last   rec: CFSv2 month 9
other  rec: CFSv2 3-mo average
 TrgSeason    SST34
   201811     0.80
   201812     0.83
   201901     0.93
   201902     1.03
   201903     1.20
   201904     1.25
   201905     1.26
   201906     1.20
   201907     1.11
   201908     0.97