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
   201604     1.11
   201605     0.24
   201606    -0.53
   201607    -1.06
   201608    -1.26
   201609    -1.34
   201610    -1.37
   201611    -1.41
   201612    -1.51
   201701    -1.59