CFSv2 Seasonal SSTs (clim19912020)
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
   202405     0.41
   202406     0.08
   202407    -0.31
   202408    -0.70
   202409    -1.05
   202410    -1.25
   202411    -1.37
   202412    -1.36
   202501    -1.16
   202502    -0.87