After a two-week window of anger, the tropics calmed down a bit. But now, at the historic peak of the Atlantic hurricane season, there are signs that the atmosphere could come to life again. We observe a tropical storm and three areas to watch and see a possible burst of activity from late September to early October.
Tropical Storm Gabrielle
Gabrielle stutters since Wednesday morning as an intermittent tropical cyclone. It crumbled to a lows low on Friday, but soon came to life again like a tropical storm. Since then, Gabrielle meanders around the North Atlantic, sealing off central winds at a speed of 80 km / h. Over the open ocean, Gabrielle will soon switch from a tropical to an extratropical storm as she flies towards the north of Britain at the end of the week. Ireland and Scotland saw windy rain showers Wednesday evening through Thursday.
System # 1
In the meantime, we are turning to the Gulf of Mexico, where a system could approach late in the week. At the moment it is centered north of Hispaniola and occasionally produces showers and thunderstorms. Over the next few days, the confused thunderstorm will jump to the southern Bahamas and cause a penny to two inches of rain, while thunderstorms overhang the Florida Peninsula on Thursday.
Friday to Saturday, the wave will move into the Gulf of Mexico, along the northern periphery of the Gulf. This would put the Gulf Coast of Florida, Mississippi, Louisiana and, yes, Alabama in the queue for showers and thunderstorms this weekend.
If the system is off the coast long enough, there is a chance that it will develop into a tropical storm. The National Hurricane Center gives this opportunity a 30 percent chance over the next five days, but those odds could be increased.
Conditions are conducive to development, but the intensity of a potential system would be limited A name, a cloud of very humid air, will arrive on Sunday night on Monday night on the Gulf Coast of Texas. This increases the likelihood of heavy downpours and potential flooding from Houston to Lake Charles. If you were playing "Pin the Tale on a Surface Pad," it would probably be pretty difficult. As a result, the development opportunities of 94L are limited. (NOAA / Tropical Tidbits)
This sub-tropical tidal wave is currently located about 900 miles east of the Windward Islands. The prospects of developing into a tropical depression or tropical storm are limited to 20 percent, according to the Hurricane Center. While some organization is possible the next day or so, it is not long for this world. The Hurricane Center says that "winds at higher altitudes are likely to be unfavorable to the formation of tropical cyclones".
System No. 3
It is very early to call this system. The wave has recently left the African coast south of Cape Verde. There is nothing to encourage or ignite, but this could change next week as the system nears the Lesser Antilles. How it develops after that remains to be seen, but the development opportunities are rather low for the time being.
However, do not exclude it. "A handful of European members of the model ensemble were optimistic," wrote Brian McNoldy, CWG's expert on tropical weather. Most of the Atlantic is warmer than average, he writes except for the waters around Cape Verde. This is "the first environment young African waves encounter when they leave the nest," McNoldy writes. We will not understand this system until it approaches 50 degrees west.
However, this could prove mischievous down the line. The Hurricane Center gives him a 20 percent chance of becoming an organized system.
End of September / Beginning of October
Despite the lull in hurricane activity, Tuesday (10th September) marks the peak of the Atlantic hurricane season. If you select a random day from a random year, September 10th is most likely to have a tropical cyclone in the Atlantic.
There are indications that tropical activity will increase again towards the end of September to the beginning of October. So while systems remain possible in advance, the atmosphere will be put into a second round of "Turbo Boost" mode in about two weeks.
The reason? Much has to do with a convectively coupled Kelvin wave. These are very sluggish, large-scale "waves" in the equatorial atmosphere, which essentially have a sinking motion at their leading edge and rise in their wake. They move east, unlike most tropical weather systems that go west.
A convectively coupled Kelvin wave is not a storm system. Instead, it's a kind of overturning circuit that can either suppress or boost rising air. From this we know that tropical cyclones that thrive on rising air have a much greater chance of developing on the back of a passing convective coupled kelvin wave. The Madden-Julian oscillation, which will further enhance the ascending movement across the Atlantic, is coming End of September to beginning of October.
Michael Ventrice is a tropical weather forecaster at the Weather Company, specializing in convectionally coupled Kelvin wave work. He has proven to be a useful predictor of regular improvements in hurricane activity.
"In the long run, the European model and its 51-member ensemble predict that [Madden-Julian Oscillation] will act swiftly, transitioning to Phase 1 and 8 by the middle of next week," McNoldy writes. Put simply, these phases promote increased hurricane activity.
How long will it be from 26th September to 10th October? Stay tuned.