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Two Atlantic Tropical Weather Systems (H. Michael Mogil, CCM, CBM, NWA-DS*)

During the past two days, the tropical Atlantic has come to life. Two weather systems are in the news this Monday morning (Fig. 1).

The first is Potential Tropical Storm TWO, that is moving rapidly westward toward the southern Windward Islands. This very low-latitude tropical weather system is expected to reach tropical storm intensity before it reaches the island chain on later today, tonight or early Tuesday (Fig. 2). As of 8:00 a.m. E.D.T., the system was not yet a named tropical storm even with sustained winds of 40 miles per hour.

According to David Zelinsky, a meteorologist at the National Hurricane Center (NHC), “Although the winds meet the threshold for a tropical storm, the system does not yet possess a closed well-defined surface circulation (emphasis mine), so it isn’t classified as one. Since the system still has the potential to bring tropical storm impacts, the NHC now has the option to issue advisories for ‘Potential Tropical Cyclones.’ This way, we can still issue all of the appropriate warning products on time, rather than waiting for the system to finish developing.”

The second system is of more immediate interest to the U.S. This involves a, “broad area of low-pressure located near the east coast of the Yucatan Peninsula.” The system is lopsided with most of the strong winds (as high as gale force) and heavy rainfall located on the east and northeast sides of the system.

NHC, in its 8:00 a.m. E.D.T intermediate advisory, noted that, “the low-pressure area still lacks a well-defined center of circulation.”

Lacking a center, and being so close to land, this system will likely await its transit into the Gulf of Mexico before intensifying. However, during the next few days, there is a very high likelihood of the system warranting a tropical storm name.

© 2017 H. Michael Mogil

Originally posted 6/19/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.