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
   201711    -0.74
   201712    -0.96
   201801    -1.11
   201802    -1.19
   201803    -1.10
   201804    -0.99
   201805    -0.84
   201806    -0.68
   201807    -0.53
   201808    -0.49