Today is Saturday 23 August 2020 and there are two tropical cyclones, LAURA and MARCO in action basically chasing each other. These named-storms started their respective journeys around 4 August as tropical waves generated over equatorial Africa moving west toward the far east Atlantic, south of the Cape Verde Islands.
By 7 August one of these tropical waves had emerged over the waters of the east Atlantic to travel west along ‘Hurricane Alley’, followed three days later by another tropical wave taking the same route toward the Lesser Antilles and the Caribbean beyond.
While the first of these two tropical waves brushed past Barbados and entered the Caribbean aiming toward Central America to eventually become Tropical Depression #14, the one following behind became Tropical Depression #13 mid-way along Hurricane Alley aiming toward the Leeward Islands.
On 21 August TD #13 became Tropical Storm LAURA near the northern Leeward Islands and the Virgin Islands on a track that would take it to the open Atlantic north of the major islands of the Antilles toward Florida and the Gulf of Mexico. Some twelve hours later, also on 21 August, TD #14 became Tropical Storm MARCO as it brushed near Cabo Gracias a Dios (“Cape Thanks God”) and the Nicaragua/Honduras border, the same cape that Columbus named in 1502 after outrunning and escaping another Caribbean tropical cyclone.
It is of interest to note that the tracks of both these tropical cyclones had shifted over the previous day or so toward what could be characterized as a converging common line aiming at the central Gulf of Mexico where surface water temperatures are quite hot at close to 31 Celsius (~88 F), in the general direction of Louisiana. It is clear that these storms are influencing each other as they grapple with a complex ocean-atmosphere environment involving various features in addition to moderate to strong wind shear and surrounding dry air. It is also clear that the warm waters of the Gulf and the accumulated heat content are acting as a magnet for both LAURA and MARCO, and may eventually contribute to their potential strengthening into hurricanes before landfall in coming days.
We will soon have the initial reports of damage from the Leeward Islands, the Virgin Islands, Puerto Rico, Dominican Republic, Haiti, Cuba, Jamaica, Nicaragua, Honduras, Belize, the Yucatan Peninsula of Mexico, and eventually from the USA Gulf states affected by either or both LAURA and MARCO. It will be interesting to learn what effect the hot waters of the Gulf ended up having on the intensity and tracks of these tropical cyclones. While we anticipate those initial reports and the eventual after-action full reports, I believe it is remarkable to think that LAURA and MARCO have been active for almost three weeks already, and to imagine that they may have been in motion for much longer than that because it is quite possible that they started as weather impulses a week or two earlier over the Indian Ocean, which moved west over the horn of Africa to become rain storms or thunderstorms, and eventually morphed into the tropical waves that initiated their journeys as summarized here.
There is no question that the 2020 Atlantic Hurricane Season has been quite active so far. It started early, in mid-May, and has already generated 13 named tropical cyclones, five of these in the first three weeks in August as we come upon the 28th anniversary of Hurricane ANDREW (1992), which was the first named-storm of the 1992 Atlantic season. And to think that 55% of the 2020 season is still ahead. So there will be plenty of activity over the next three plus months. Let’s see what lessons Mother Nature has in store for us regarding cyclogenesis!
Elsewhere in the northern tropics, Typhoon BAVI is tracking some 250 kilometers northeast of Taiwan aiming for the Korean Peninsula. Closer to our neck-of-the-woods we are monitoring a cell of disturbed weather, in the northeaster Pacific, 275 kilometers south of Puerto Angel in the State of Oaxaca, Mexico, and another one approximately 1500 kilometers southeast of the Big Island of Hawaii in the central Pacific. Both of these disturbances show potential for further development.
Despite the rather active Atlantic Hurricane season, overall the rest of the northern tropical basins for cyclogenesis have been somewhat quieter than what has been usual over the past few years. In the Atlantic basin itself we have had a lot of activity, but very few hurricanes. I will venture the opinion that global warming and other climate factors or effects are raising the threshold for cyclogenesis to occur. We would need to conduct a comprehensive comparative analysis of past hurricane seasons to determine if this is indeed the case, but in my opinion it is something to consider.
For all of those that may be affected by what remains of the 2020 Atlantic Hurricane Season, please remain alert. Be prepared. MITIGATE!