INTERESTING EL NINO
Good morning everyone!!!
Well , the news media is at it again with the overhype of this so called super el nino. Quite frankly not only do the observations point to this not occurring , but
this elnino has had me quite curious all summer long and here is why. Im sure as you have all noticed with this el nino the warmest SST have been and continue to be
around the eastern portions or nino 1+2. Now , if you said to me hey steve , this is an east based elnino and the convection should be around 1+2 , well, you would be correct in that thinking.
After all the warmest SST argue where the warm air rises into a cooler upper air environment. the latent heat release from that convection alters the thermal structure of the mid levels which eventually enhances
the mid and then upper level jet streaks. this jet streak enhancement then influences the sub tropical and polar jet stream configurations. However , this is not what has been or is occurring with this el nino.
With this el nino the convection has been basin wide with an emphasis around the date line. this convection would normally point to a more west based( nino 4) or at least a central based nino.
Major learning experience here ,it is not enough to just look at where the warmest SST are and draw conclusions. Where the majority of the convection is occurring will fundamentally have an impact
on the 500mb pattern. I suspect here with this el nino given we are in a strong +pdo pacific regime , that this is certainly why convection has been more focused towards the date line as a +pdo puts a trough south of the aleutions. This trough base around the date line
then becomes amplified and further amplify the trough/ridge relation downstream over north america.
Unlike in previous super el nino years like 97-98 the pdo was not as strong ( which gave more relation between where warmest SST are & hence convection was) along with sub surface temps very much warmer than this year. the convection that year was certainly more focused around
nino 3 and 1+2 leading to a completely different 500mb pattern. Remember here , convection around the date line enhances the subtropical jet stream for the desert southwest , southern plains and much of the eastern US. Convection around the date line also supports a -AO/NAO
pattern. Kind of interesting here as the basin wide nino convection is more influenced from the position and strength of the polar jet stream rather than el nino influences driving the polar jet stream. In short , if we took this current pattern
placed it in the cold season it would be very interesting.
Meteorologist Steve Garry