Seasonal Forecast
Seasonal
Forecasts for the 2010 Atlantic Basin Hurricane Season
The
2009 Atlantic Basin Hurricane season was an average one. The
first seasonal forecasts issued by the
Colorado State
University (CSU) for the
2010 Atlantic Hurricane Season issued by the CSU
was
published on December 9, 2009, the second one came out on April 7, the
third was issued on June 2 and the fourth appeared on
August 4,
2010. More updates will follow in early September and October.
Information obtained through July 2010 indicates that the 2010 Atlantic
hurricane
season will be much more active than the average 1950-2000 season. The
forecasters of the CSU estimate that 2010 will have about 10
hurricanes (average is 5.9), 18 named storms (average is 9.6), 90 named
storm days (average is 49.1), 40 hurricane days (average is 24.5), 5
major (Category 3-4-5) hurricanes (average is 2.3) and 13 major
hurricane days (average is 5.0). The probability of Caribbean major
hurricane activity and U.S. major
hurricane landfall is
estimated to be well above its long-period average. These forecasters
expect Atlantic basin Net Tropical Cyclone (NTC) activity in 2010 to be
approximately 195 percent of the long-term average. The CSU forecasters
have increased their seasonal forecast from early April but have
maintained their June forecast amount of tropical cyclones.
Forecasters of the National Oceanic
and Atmospheric
Administration (NOAA)
in the U.S.A. have also
issued
a seasonal
forecast for the 2010 Atlantic Basin tropical cyclone activity in
August. This
forecast calls for an 90% chance of an
above normal season. The outlook indicates only a 10% chance of a
near-normal season and a 0% chance of a below-normal season. The
conditions expected this year have historically produced some very
active Atlantic hurricane seasons. The 2010 hurricane season could see
activity comparable to a number of extremely active seasons since 1995.
If the 2010 activity reaches the upper end of NOAA's predicted ranges,
it will be one of the most active seasons on record.
NOAA forecasters estimate a 70% probability for each of the following
ranges of activity this season: 14-20 Named
Storms, 8-12
Hurricanes and 4-6 Major Hurricanes.
The activity is expected to fall within these ranges in about 70% of
seasons with similar climate conditions and uncertainties to those
expected this year. They do not represent the total possible ranges of
activity seen in past similar years. These ranges include the two
tropical storms and one hurricane seen to date.
During June – July 2010, two named storms (Hurricane Alex and Tropical
Storm Bonnie) formed in the Atlantic basin. The pre-season outlook
issued in late May reflected the possibility of even more early-season
activity. As a result, the upper ends of the predicted ranges have been
reduced. Nonetheless, significant activity is predicted for the remainder of the season, with
an additional 12-17 named storms, of which 7-11 are expected to become
hurricanes with 4-6 reaching major hurricane status.It should be noted that these seasonal forecasts have limited
operational value. This means that no matter how many tropical cyclones
are forecast to develop, there is no way to predict so many months in
advance where a certain tropical cyclone is going to develop
and what areas, if any, will be affected. Remember too that
it takes only one major hurricane in even a quiet season (Andrew in
August 1992 over South Florida) to move over a populated area to make
it a significant event.
Therefore,
it is important that the entire community in the hurricane region
prepares itself before the start of each hurricane season. The
Meteorological Service will continuously monitor the development of any tropical
disturbance closely and will issue watches or warnings in case this is
necessary. The moderate El Niņo phase which dominated the weather over
our islands during especially the second
half of 2009 and the first quarter of 2010 is now history. It was the
main reason of
the below average rainfall
observed during the 2009 rainy season (-74%) in the ABC Islands. In
fact, with so little rain,
the rainy season in these
islands was uneventful. Even the SSS Islands, which should have
received average
rainfall during the second half of 2009, received less than
that.
Sea Surface
Temperatures (SST) in the
tropical Pacific Ocean have decreased
in the meantime (August 2010) to below average values and that has
already lead to above
average values of rainfall in the ABC Islands. In the
Atlantic Ocean and the Caribbean Sea, the sea
surface temperatures are already at above average levels and the
outlook is for these higher than normal temperatures to persist
throughout the remainder of 2010. This is forecast to
result in a good chance of significant rainfall for both the ABC
and the SSS islands during the second half of
2010, including the upcoming rainy season (October-December).
Last
updated: August 20, 2010.
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Aruba,Bonaire, Curaçao |
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St. Maarten, St. Eustatius, Saba |
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