Fig. 1-2: Gulf of Mexico SSTA analysis and 30-day change.
Discussion: Of EXTREME importance during the 2022 North Atlantic tropical cyclone season is tropical cyclone tracks into suddenly much warmer surface water/upper ocean heat. We’ve seen many storms in the 2016-2021 active North Atlantic cycle which have somewhat unexpectedly intensified rapidly, usually into category 3, 4 or 5 major hurricanes when passing over suddenly very warm water. Usually, the threshold for this type of strengthening has been in the 86-87F/30-31C range in the western Caribbean Sea or the Bahamas and 87-88F/31-32C in the north or west Gulf of Mexico. Many times, passage over the suddenly very warm water and the attendant rapid intensification is close to a landmass sometimes preceding landfall. Right now, the Gulf of Mexico has warmed to a basin average of +0.93C (Fig. 1) which is a whopping +0.99C change in the past 30 days (Fig. 2). If this trend were to continue, over-achieving intensity of early season storms in the Gulf of Mexico are likely. In the western North Atlantic basin, the SSTA pattern is mixed with a basin average of +0.31C and a 30-day change of -0.70C (Fig. 3-4). The cooler waters off the East Coast were poorly forecast by global SSTA models. In the deep tropics, SSTA pattern is near normal. The April 2022 tropical North Atlantic (TNA) index was -0.01 which is down from the very warm +0.61 observed in January.
Fig. 3-4: Western North Atlantic basin SSTA analysis and 30-day change.