North Atlantic Basin Still Cooling As Tropical Cyclone Season Approaches

PDO is Neutral BUT is the Longterm Cycle Changing to Warm Phase?
05/18/2018, 11:08 am EDT
Tropical Cyclone 10-Day Monitor
05/23/2018, 12:09 pm EDT
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Large regions of both cool and warm water are present across the North Atlantic. The eastern tropical North Atlantic is particularly cool. The trend favors lowering risk of strong hurricanes developing in the deep tropics if this trend continues.

Discussion: Tropical cyclone season begins June 1 in the North Atlantic basin. Playing a significant role in the character of the upcoming season is the sea surface temperature anomaly (SSTA) especially in the tropics and subtropics.

Currently, the North Atlantic basin-wide SSTA is -0.01C and the 2-week change is -0.26C. The main development region (MDR) for hurricanes located in the deep tropics between northwest Africa and the Caribbean Sea is a whopping -0.85C and has cooled by 0.41C over the past 30 days.

There is a warm “blob” well east of New England and shifting east. South of Greenland is the likely driver of both cool SSTA in that region and the deep tropics as a large cool pool driven by ice melt from Greenland is strengthening. Subsurface currents driven by the cool pool of water traveling southward are likely affecting the tropics.

The Gulf of Mexico is warmer than normal but has cooled slightly over the past couple weeks. The general cooler trend especially in the tropics does not bode well for an active tropical cyclone season.