Tropical Storm Gonzalo (2020)

Storm Active: July 21-25

Around July 17, a tropical wave associated with a monsoonal trough of low pressure near the equator entered the Atlantic from the east. To its north, plentiful dust-laden air still streamed westward off of the Saharan desert over the ocean. For the first part of July, this Saharan air layer (SAL) contributed to a very dry tropical Atlantic and stifled the season's early tropical waves. This wave, however, stayed low in latitude and produced persistent shower activity as the trade winds guided it westward.

There was an elongated area of enhanced vorticity associated with the system for a few days, but no single circulation center. Some spin became apparent early on July 20, when a surface low formed. Though the circulation became better defined by the evening, thunderstorm activity was still a bit spotty and winds remained lackluster. The system entrained more moisture from the inter-tropical convergence zone (ITCZ) to the south on July 21, and strengthened a little, earning the designation Tropical Depression Seven late that afternoon. Organization steadily increased overnight, and the storm became Tropical Storm Gonzalo during the morning of July 22. Following in the footsteps of earlier storms of the 2020 season, Gonzalo was the earliest ever seventh named storm, beating out Gert of 2005, which formed July 24 of that year.

The steering pattern near Gonzalo was quite simple: a strong subtropical ridge to its north kept it traversing the 10°N parallel at a gradually increasing speed. Environmental factors were more mixed, however. Ocean temperatures were quite warm and wind shear was fairly low, but the SAL lurked to the north and the system was fighting dry air. That day, Gonzalo lost some of its outer banding features even as the inner core improved and it strengthened some. The small cyclone peaked at 65 mph winds and a pressure of 997 mb that night, but the central dense overcast promptly collapsed a few hours later as dry air invaded Gonzalo. The storm ejected a blob of convection to the west, but the circulation was nearly bare apart from that by the morning of the 23rd, leading to some weakening.

A small shield of thunderstorm activity made a comeback later that day, once again covering the center of circulation, but the weakening trend continued throughout the next couple of days as the central pressure rose. Meanwhile, Gonzalo's westward motion had hastened, making it more difficult for the cyclone to maintain a closed circulation. During the morning of July 25, Gonzalo made landfall in Trinidad as a minimal tropical storm and weakened to a tropical depression shortly after. Land interaction further sealed the cyclone's demise and what was left of the circulation dissipated that afternoon. Though fast moving, Gonzalo brought heavy rain to portions of the southern Windward Islands and northern Venezuela. After dissipation, the remnant tropical wave continued west-northwestward through the eastern Caribbean.

The above images shows Gonzalo over the open tropical Atlantic. Despite warm waters, dry air and stable air eventually overwhelmed the small cyclone.

Gonzalo took an unusually southern track, ultimately affecting South America.