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
   202005     0.04
   202006    -0.33
   202006    -0.33
   202007    -0.54
   202008    -0.73
   202009    -0.82
   202010    -0.88
   202011    -0.93
   202012    -1.01
   202101    -0.94
   202102    -0.73