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
   201902     0.64
   201903     0.87
   201904     1.10
   201905     1.26
   201906     1.39
   201907     1.49
   201908     1.48
   201909     1.45
   201910     1.43
   201911     1.44