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
   201912     0.32
   202001     0.37
   202002     0.45
   202003     0.41
   202004     0.32
   202005     0.18
   202006    -0.03
   202007    -0.24
   202008    -0.49
   202009    -0.74