Hammy wrote:NotSparta wrote:aspen wrote:So it would seem what happened in late 2021 — the high pressure suddenly becoming too strong and shutting down deep tropic activity — has continued to plague 2022. What even caused that? It just came up out of the blue, right after a >50 ACE Cat 4/5.
Two totally different things going on
From Late September onward along with much of July and August of this year had viable low-level waves being too far south to develop, that ended up in the East Pacific instead--the latest being the GFS phantom storm's incipient disturbance. The high in both instances was certainly stronger and displaced much further south and west, inhibiting these disturbances from making any northward progress.
This same high is very likely why the north Atlantic has warmed so significantly and also contributed to the limited subtropical activity (one storm so far in the central Atlantic, and only one after October last year the entire rest of the season.) Absent any alternate explanation there seems to be little difference.
In 2021 it was the Atlantic Niño, early this year was pretty normal then came the dry air that mostly choked out the waves. The subtropical Atlantic didn't really warm up anomalously in October 2021 because the root cause of the inactivity was a different one, mostly being the upper troughing started off by Sam and the Atlantic Niño keeping the ITCZ equatorward. This year it's dry air and all those cutoffs once you get into the WATL. The subtropical Atlantic actually warmed up unlike last fall as the pattern caused persistent anticyclogenesis this summer. Just a coincidence that both meant quiet. With one being late in one year and the other most of the next one it's led many to come to this dubious conclusion
