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
   202107    -0.22
   202108    -0.36
   202108    -0.36
   202109    -0.54
   202110    -0.67
   202111    -0.75
   202112    -0.70
   202201    -0.56
   202202    -0.40
   202203    -0.17
   202204     0.08