Ten and Counting! It is still August

Think back to 1992; it was 17 August when ANDREW the first-named tropical cyclone of the season was generated from a tropical depression, which had activated about half-way through Hurricane Alley some 1,000 km to the southwest of the Cape Verde islands.

Water-vapor satellite image showing tropical storm IRENE impacting the northeastern USA and eastern Canada on 28 August 2011

Flash forward to the 2011 Atlantic hurricane season! It is Sunday 28 August and at the same time that IRENE, the first hurricane of the season now degraded to tropical storm strength, ravages the northeastern USA and eastern Canada with 100+ kph winds and huge amounts of rain, tropical storm JOSE had activated to the south of Bermuda.

Color-enhanced infrared satellite image showing tropical storm IRENE and newly generated tropical storm JOSE on 28 August 2011

Now we are up to 10 named Atlantic tropical cyclones in 2011 and it is still August. The last time there were ten tropical cyclones before the end of August in the Atlantic basin it  was in 2005, when we saw a historical season of 28 named storms and we had to use the letters of the Greek alphabet to name the last six storms. The next previous season we had had ten named tropical cyclones before the end of August in the Atlantic was in 1995 when tropical storm JERRY spawned north of Cuba near the western Bahamas and made landfall in Florida on 23 August. The 1995 Atlantic hurricane season ended with a total of 19 named tropical cyclones; quite an active season, and one which in the consensus of most scientists marked the start of a multi-decadal period of increased tropical cyclone activity in the Atlantic basin that continues today 17 years later. [ if you are interested in seeing complete records of past annual Atlantic hurricane seasons please visit: http://www.nhc.noaa.gov/pastall.shtml#tracks_all ]

What does it all mean for us? Will 2011 be a record-breaking type season such as the one in 2005 or still an above-average-but-not-as-active, similar to the 1995 Atlantic hurricane season? NOAA’S Climate Prediction  Center [ for more on NOAA’s  2011 Atlantic season prediction, go to: http://www.noaanews.noaa.gov/stories2011/20110519_atlantichurricaneoutlook.html ] estimated we will see as many as 18 named storms generating in the Atlantic basin in 2011, which means we are already 56% there with about 51% of the official 2011 season still left to go. Speaking strictly in statistical terms it would appear there is a  a slightly higher than average chance that we may have at least a 1995-type season reaching the 18 total named storms predicted by NOAA for the 2011 Atlantic hurricane season.

Satellite image for the aviation industry showing a large tropical wave just south of the Cape Verde islands over the warm waters of the eastern Atlantic, moving west toward hurricane alley, on 28 August 2011

Looking toward the east we see a couple of larger tropical waves to the west and southwest of the Cape Verde islands, and also a couple of minor waves over equatorial Africa. However it is interesting to note that, at least for now, the amount of tropical activity we have seen over equatorial Africa over the past few weeks appears to have subsided considerably, and the same can be noted about the western ranges of the northern Indian ocean.

Consequently, intuitively at least, it would appear there are a couple of cells of disturbed weather currently over the eastern Atlantic that may see cyclonic development in the next few days, but beyond that the tropical wave assembly lineis rather empty for now. Also, there are no good candidates

Mosaic of water-vapor satellite images showing the northern tropics from the eastern Pacific to the Indian ocean on 28 August 2011

for seeds of future tropical cyclone in any of the sub-basins at least for now. We will have to wait and see what weather patterns may evolve over the next few days, which may construct a favorable environment for potential tropical cyclone development anywhere in the Atlantic basin leading into the first days of September. Keeping in mind that September has historically been the most active month for cyclogenesis in the Atlantic basin, it is entirely possible we could see significant cyclonic activity over the next few weeks. We will have to wait and see.

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