'Genuine' concerns of tropical storm in Gulf of Mexico SOON
Thursday, August 30, 2018, 11:19 AM - There are several indications that the Atlantic hurricane season will spring to life as we head towards what is typically the most active time of year for tropical storms and hurricanes in the Atlantic, early to mid September. Several systems will track from Africa into the tropical Atlantic during this time frame and each of these systems will have to be watched closely. More on the possible trouble brewing around Florida and the Gulf of Mexico next week PLUS a look at how Hurricane Norman threatens Hawaii after the very recent record rainfalls from Hurricane Lane.
THE SEASON SEEMS QUIET SO FAR
The hurricane season has been rather quiet so far this year, especially during the past month. Several factors have contributed to this quieter pattern including the cooler than normal ocean water temperatures that have been found in the tropical waters of the Atlantic Ocean. In addition, we have had higher than normal surface pressure, an abundance of dry air, and an overall sinking motion in the atmosphere over the region. All of these factors create a hostile environment for the development of tropical storms and hurricanes.
However, a much more active pattern will develop for the next few weeks as all of the factors which have been limiting tropical development are in the process of reversing.
HERE'S WHERE WE NEED TO WATCH NEXT
Our first area of concern next week will be around Florida and the Gulf of Mexico. While it is much too early to talk about the exact strength or track of any systems, the overall pattern will be conducive for development in this region and we are increasingly concerned that we will have a tropical storm or hurricane in the Gulf of Mexico by the middle to end of next week. Even if we do not end up with a named storm, we expect a rather rainy and unsettled pattern across Florida and along the Gulf coast.
We also expect a tropical system to form between the coast of Africa and the Cabo Verde Islands in association with a tropical wave that will move off the west coast of Africa late this week. A tropical depression could form over the weekend while the system moves west-northwestward near the Cabo Verde Islands. Interests in those islands should monitor the progress of this system. However, this storm is not expected to have an impact on North America as it will turn north long before it approaches our coastline.
Several systems will track from Africa into the tropical Atlantic during early to mid-September and each of these systems will have to be watched closely.
THE CHANGES COMING IN SEPTEMBER
The overall pattern will support falling surface pressure and more upward vertical motion (rising air) across the western half of the main development region of the Atlantic Basin where sea surface temperatures have warmed significantly during the past few weeks.
Below we highlight the current pressure anomalies in the Atlantic Ocean. The various shades of orange highlight the higher than normal surface pressure that we find across the western and central Atlantic.
However, we expect a very different pattern by the end of the first week of September, with the various shades of blue indicating lower than normal pressure across most of the tropical Atlantic, indicating an environment more favourable for development.
In addition, several “triggers” for tropical development will be tracking into this region.
The map below also highlights that much of the western and central Atlantic are now warmer than normal (as indicated by the various shades of yellow, orange and red).
While there is still some cooler than normal water to the west of Africa, the water is now warmer than normal across the Caribbean and off the East Coast of the U.S. and Canada.
Of particular concern is how warm the water is just offshore of the Canadian and American coastlines. If any tropical storms or hurricanes track into these regions, this would contribute to a higher threat for the storms to maintain strength rather than weaken as they approach coastal areas.