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
   201905     0.74
   201906     0.76
   201907     0.81
   201908     0.78
   201909     0.81
   201910     0.83
   201911     0.82
   201912     0.72
   202001     0.63
   202002     0.56