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
   202407     0.03
   202408    -0.37
   202409    -0.83
   202410    -1.20
   202411    -1.39
   202412    -1.41
   202501    -1.20
   202502    -0.85
   202503    -0.47
   202504    -0.10