12:00 PM | *A burst of tropical activity over the next 2-3 weeks in the Atlantic...possible impact on Florida and Gulf of Mexico as soon as early next week...another system out over the Atlantic*
Paul Dorian
Colorized IR imagery features two areas of interest in the Atlantic Basin; courtesy NOAA, University of Wisconsin/CIMMS
Overview
The climatological peak of the Atlantic Basin tropical season is around the middle of September and it certainly looks like there will be a ramp up in activity after a relatively quiet month of August. In fact, there very well may be a burst of activity with potentially several named storms over the next 2 or 3 weeks taking us right into the middle of September. Two areas of interest currently exist and the "front-runner" of these two systems could actually have an impact on Florida and the Gulf of Mexico by the early-to-middle part of next week. The second system is still not far off of Africa's west coast and it will have to be closely monitored given the expected strong high pressure ridging next week across the Northeast US and southeastern Canada.
Accumulated Cyclone Energy (ACE) has been running at below-normal levels in the North Atlantic, but that could change quite a bit over the next 2 or 3 weeks; data courtesy Dr. Ryan Maue, weathermodels.com
Discussion
While the Pacific Ocean has had a very active start to the tropical season, the Atlantic Basin has been relatively quiet with accumulated cyclone energy (ACE), a measure of tropical storm intensity and duration, well below-normal for this time of year. The overall pattern, however, appears to be setting up for a burst of activity over the next 2 or 3 weeks that certainly could raise ACE levels considerably higher in the north Atlantic.
Persistent high pressure ridging over southeastern Canada and the Northeast US is always a red flag this time of year in terms of potential tropical activity. This type of upper air pattern allows for the general east-to-west movement of tropical waves over the Atlantic Ocean towards the Southeast US and Gulf of Mexico. Courtesy NOAA/EMC, tropicaltidbits.com
To begin, abnormally strong high pressure ridging is likely to set up shop over SE Canada and the Northeast US in coming days and this is often associated with (compensating) lower pressure in the southwestern part of the Atlantic Ocean. The 500 mb height anomaly forecasts for the current 5-day period and days 6-10 feature persistent well above-normal levels extending from the Great Lakes to New England to southeastern Canada. This type of upper air pattern would allow for the general east-to-west movement of tropical systems towards the Southeast US including Florida and the Gulf of Mexico from the open Atlantic Ocean. In addition to the upper-level heights, sea surface temperatures are generally running at above normal levels in the southwestern Atlantic and Gulf of Mexico which will likely aid in the formation or intensification of tropical systems in coming days.
There are currently two areas of interest in the tropical Atlantic. One wave is quite noticeable in satellite imagery just off the west coast of Africa in the far eastern Atlantic. This system has an excellent chance of intensifying in coming days and could reach hurricane status by early next week as it treks to the WNW into the open Atlantic. It is too early to tell if it will then get "picked-up" by an eastward-moving trough and head to the open north Atlantic or if it can be "left behind" by the passing trough and possibly threaten the US east coast at some point down the road. If indeed this system is not picked up by the eastward-moving trough and pushed to the north then the widespread strong high pressure ridging to our north could force it towards the US east coast.
Current sea surface temperatures are generally warmer-than-normal in the southwestern Atlantic Ocean and Gulf of Mexico and this is usually a favorable factor for the formation or intensification of tropical systems; courtesy NOAA, tropicaltidbits.com
The conglomerate of clouds and thunderstorms over the northeast Caribbean Sea is perhaps of greater overall concern compared to the African wave and it is definitely of more immediate concern. This tropical wave may very well intensify in the next few days and head towards the warmer-than-normal waters of the southwestern Atlantic near Florida. There are indications from computer forecast models (e.g., Euro) that this system could ultimately close in on the Florida Peninsula from the east or southeast by the time Labor Day (Monday) rolls around. This kind of track makes sense given the expected upper air pattern (i.e., strong high pressure ridging to the north). If this system were indeed to make it to Florida by Monday or so, it could easily then spill out over the northern Gulf of Mexico given the expected persistent upper-air flow from east-to-west. Once out over the Gulf of Mexico, intensification would be likely given the favorable sea surface temperature pattern - perhaps to tropical storm or even hurricane status. Whether or not this system ultimately reaches "named" status, there is likely to be a lot of rainfall for parts of Florida and the Gulf of Mexico region over the next several days.
This expected burst of tropical activity is likely to bring a lot of rain over the next ten days to Florida and the Gulf of Mexico region; courtesy NOAA, tropicaltidbits.com
Stay tuned…it looks like a burst of tropical activity is on the way in the Atlantic Basin.
Meteorologist Paul Dorian
Perspecta Weather
perspectaweather.com