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
   202009    -0.86
   202010    -1.27
   202010    -1.27
   202011    -1.80
   202012    -2.25
   202101    -2.36
   202102    -2.05
   202103    -1.48
   202104    -1.07
   202105    -0.77
   202106    -0.50