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
   201901     0.59
   201902     0.69
   201903     0.89
   201904     1.01
   201905     1.02
   201906     1.03
   201907     0.98
   201908     0.79
   201909     0.62
   201910     0.55