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
   202001     0.36
   202002     0.48
   202002     0.48
   202003     0.44
   202004     0.27
   202005    -0.04
   202006    -0.41
   202007    -0.75
   202008    -1.05
   202009    -1.23
   202010    -1.35