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
   201906     0.51
   201907     0.25
   201908    -0.10
   201909    -0.33
   201910    -0.41
   201911    -0.46
   201912    -0.57
   202001    -0.60
   202002    -0.42
   202003    -0.12