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
   202303    -0.14
   202304     0.18
   202305     0.49
   202306     0.93
   202307     1.27
   202308     1.55
   202309     1.77
   202310     2.01
   202311     2.15
   202312     2.15