I have been keeping track of MDR SSTAs every day in May, and things seem to be
more favorable than 2021 but less favorable than 2020. From May 1 to May 16, these have been the daily MDR SSTAs:
0.256 C
0.261 C
0.202 C
0.180 C
0.229 C
0.300 C
0.345 C
0.336 C
0.355 C
0.432 C
0.463 C
0.344 C
0.262 C
0.268 C
0.238 C
0.196 C
So far, the average MDR SSTAs from May 1 to May 16 have been 0.295 C. Usually, MDR SSTAs rise by about 0.4 C* from May to September; this was the case for 2018, 2020, and 2021 (2019 was an anomaly; MDR SSTAs rose by about 0.6 C from May to September). By this token, if the May MDR SSTA average continues to hover around 0.3 C, September could feature an MDR about 0.7 C above-average, which will be greater than 2021 (0.6 C) but less than 2020 (0.8 C). Overall, this season is expected to have a very similar similar pattern to 2020 (+AMO, -PDO, +AMM, -ENSO, Atlantic Nina), but MDR SSTAs are not likely to exceed those of 2020 during September, giving it a slight disadvantage over 2020; however, this season does have an advantage over 2021 because of the lack of an Atlantic Nino, the thing that killed the late season for 2021, combined with the warmer MDR.
This current strong trade burst is expected to continue until about May 21, but afterwards trade winds are expected to weaken; we just need to see what happens with that.
*MDR SSTAs in May do not directly matter; a favorable pattern for May matters much less than an unfavorable pattern for September and vice-versa. However, the current pattern for May will influence how the pattern for September by virtue of the fact that the WAM consistently warms the MDR every summer by a certain amount; there are some years, such as 2018, in which the MDR was below-average during May, and the strong WAM was just barely enough to get the MDR above-average during September (by barely enough, I mean < 0.1 C above-average).
