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
   202304     0.27
   202305     0.62
   202306     1.05
   202307     1.46
   202308     1.80
   202309     2.10
   202310     2.35
   202311     2.50
   202312     2.41
   202401     2.11