Tag Archives: Tropical Storm FRANKLIN

Tropical Storm GERT is Here! Seven Down, How Many More to Go?

Today, Sunday 14 August 2011 a new tropical cyclone, GERT. the 7th named storm of the 2011 Atlantic Hurricane Season was generated over the open water of the central north Atlantic. Late in the afternoon GERT was located some 200 kilometers to the south by southeast of Bermuda; with the storm tracking north by northwest at 12 kph GERT appear to be in route to cause significant precipitation and stormy weather over Bermuda in the early morning hours on Monday 15 August, 2011.

Visible light satellite image, courtesy of NASA, showing Tropical Storm GERT on 14 August 2011 as it moved north by northwest toward Bermuda, some 200 kilometers away, with maximum sustained winds of 75 kpk gusting to 95 kph.
Map showing projected track for Tropical Storm GERT as of 14 August 2011, courtesy of the U.S. Navy Research Laboratory

While GERT is in progress toward BERMUDA some 500 kilometers to the north of the island there is Tropical Wave 96L showing some signs of organization as it is being pulled in the wake of now-dissipated-and far-away Tropical Storm FRANKLIN. There is also Tropical Wave 92L, which has been active for the past four days, following in the wake of GERT and given a 30% probability, at this time, of developing into a tropical cyclone in the next 24 – 48 hours.

Color-enhanced infrared satellite image, courtesy of NASA, showing current cyclonic activity near Bermuda on 14 August 2011.

So the Central North Atlantic is hosting quite a share of cyclonic activity as the 2011 Hurricane Season continues to evolve at a higher level of activity than during the first 60 days. Looking farther south and east from were  all of this cyclonic activity is currently taking place to aspects are noticeable: (a) new cells of disturbed weather have moved over ‘hurricane alley’ once again completing the continuous “belt of tropical activity” that had been disrupted over the last 2-3 days, and (b) there are at least three quite large cells of disturbed weather over equatorial Africa, which as they continue to move west appear to be destined to become the next generation of tropical waves to emerge over the eastern Atlantic to march westward over ‘hurricane alley’ or, perhaps, to take the northwesterly detour FRANKLIN, GERT and tropical waves 92L, 93L and 94L have taken over the past few days. Whatever course this future tropical waves take will determine whether the next round of tropical cyclone activity will generate over the central north Atlantic or if we will see a return of cyclogenesis in the Caribbean or over the Antilles.

Color-enhanced infrared satellite image, courtesy of NASA, on 14 August 2011 showing several large tropical waves or cells of disturbed weather, withpotential for cyclonic development, marching west over equatorial Africa and the eastern Atlantic.
Composite full-disk satellite image of Earth's western hemisphere on 14 August 2011 showing the belt of tropical activity circling the planet, and the northwesterly-northerly 'detour' that generated last week to feed the current bout of cyclogenesis near Bermuda.

While we witness this surge of cyclonic activity over the central north Atlantic, we will do well by continuing to monitor potential contributors to cyclogenesis in the larger Atlantic basin as they continue to appear over equatorial Africa, the eastern Atlantic or in any of the various sub-basins [Caribbean, Gulf] in coming days and weeks. With 60% of the ‘official’ annual Atlantic Hurricane season still to come given the level of activity seen so far, and the historically most active segment of the season expected in late august and September, it behooves all interest in the Atlantic basin to remain vigilant, to pay attention! To be prepared!! And, above all, to practice MITIGATION!!!

FRANKLIN: the 6th named storm of the 2011 Atlantic Hurricane Season

Visible light satellite image, courtesy of NASA, taken in the morning of 13 August 2011

As we had anticipated the 2011 Atlantic Hurricane Season has shifted into a higher gear and on 13 August 2011 we have Tropical Storm FRANKLIN, the 6th named tropical cyclone of the season, and three tropical waves with potential for cyclonic development, all active in the Atlantic basin.

FRANKLIN was some 300 – 400 kilometers northeast of Bermuda at 0645 EST moving east by northeast, in the general direction of the Azores Islands in the North Atlantic. Because of its track and the fact that it is already moving over much cooler waters. where sea surface temperatures are below 26 Celsius, it is difficult to predict how the intensity of the storm may evolve over time and although it is expected to to decline over the next 24-48 hours it is also possible for some intensification to occur in the near term.

The National Hurricane Center is investigating tropical waves designated as 92L, 93L and 94L, which in the early morning of 13 August 2011 were respectively located at 20N-50W, 12N – 34W and 26N – 58W. All of these tropical waves are showing signs of organization and potential for cyclonic development in the next 24 – 48 hours.

Satellite image of the northwestern Atlantic on 13 August 2011 showing the four tropical systems active in the basin

As we monitor these active systems it is important to also pay attention at several cells of disturbed weather marching west over equatorial Africa, which may become the next tropical waves to emerge over the eastern Atlantic in the next 12 – 36 hours.

Color-enhanced infrared satellite image on 13 Augsut 2011 showing several tropical waves and cells of disturbed weather over equatorial Africa and the eastern Atlantic

In observing this current tropical activity in the Atlantic basin it is interesting so see how the typical “belt of tropical activity”, that typically circles the Earth near the equator, has been disrupted by strong weather fronts and ridges marching generally east by northeast over the USA and the northern Atlantic. This is shown in the composite satellite image below:

Full-disk composite satellite image of Earth's western hemisphere on 13 August 2011 showing the current disruption ot the "belt of tropical activity" around the planet