Weather Expectations from the Present Disturbance

28 10 2014

Dale C. S. Destin |

Disturbance

Disturbance

A weather disturbance has developed around 250 miles east of Antigua. It has a 20% chance of becoming a tropical cyclone (the generic term for depressions, storms and hurricanes) while it is in our area and a 30% chance of become a tropical cyclone after it moves away for the northeast Caribbean. However, this system is not expected to become a tropical cyclone as the winds aloft are not favourable for much further development. Notwithstanding, based on data available up to this morning, there are three weather scenarios looked at below with respect to the impact of the disturbance on Antigua and the northeast Leeward Islands.

Expected

The weather expected from this disturbance is: Cloudy to overcast skies with precipitation (rain and showers); thunderstorms are likely Tuesday night and Wednesday. Further rainfall accumulation of 10 to 25 mm is possible. The winds are going to swing to the southeast at 5 to 12 knots by tonight. The seas will get up to near two (2) metres or 6 feet tonight and will fall back to near 1.5 metres or 5 feet tomorrow Wednesday.

Best Case

For a best case scenario, the disturbance will get decimated by the unfavourable winds aloft. Thus, although cloudy skies will continue, not much more rainfall will take place.

Isaias_Intensity

Worst Case

For the worst case scenario, the disturbance could develop further and impact Antigua and Barbuda as a tropical depression and the rest of the northeast Caribbean as a minimal tropical storm (Isaias). This scenario is very unlikely; however, if this pans out, quick action would be required to protect life and property.

Isaias_Invest

Conclusion

Changes will definitely take place with this disturbance over the next 24 hours; however, something close to the best case scenario is anticipated. Notwithstanding, this system will be monitored and if the chance of development into a tropical cyclone rises to above 50%, a tropical cyclone alert will be issued by the Antigua and Barbuda Met Service. Residents in the Leeward Islands should continue to monitor this system until it has dissipated or out of our area.

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A Slow Start to October’s Rainfall for Antigua

20 10 2014

Dale C. S. Destin |

Rainfall continues to be a very scarce commodity in Antigua and Barbuda. Like most of the rest of the months for the past year, the rainfall for October has been quite discouraging, thus far. The first half of October has seen a significant rainfall deficit across much of Antigua according to preliminary statistics at the Antigua and Barbuda Met Service Climate Section.

Figures up to October 16 show there has been 36.0 mm of rain at the Met Office located at the V. C. Bird International Airport. This is only 50% of the October average of 71.8 mm, just about the amount that should have fallen by this point.

Rainfall_OctoberThis makes this first half of October the 16th driest at the Airport based on available records dating back to 1967. Three of the last four first half of October has seen worse rainfall deficits. However, the overall trend is positive although not significant.

Many persons were hoping that Hurricane Gonzalo would have put a dent in the drought; however, this was just not to be. The system produced only 1-5 inches across Antigua and 4-6 inches across Barbuda; however the higher totals were isolated and away from the most of the islands catchments.

The low rainfall figures appear to be due largely to sinking air associated with the Madden-Julian Oscillation in our part of the world for much of the first 16 days of October.

Of course, while these figures are interesting, they don’t tell us where the month will end up overall. A few days of wet weather, which looks unlikely at the moment, could drastically alter the statistics. So we’ll have to wait for the full-month figures before making any judgements. September had a much worse start and was able to limp into the near normal range in the end. It should be noted the rainfall for the second half of October is trending downward, although not significantly.

The outlook for the month called for near normal rainfall; thus we shall see what happens at the end of the month.

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“Tropical Storm Gonzalo” On Our Doorsteps

12 10 2014

Dale C. S. Destin

Gonzalo_Satellite1

We are following an area of disturbed weather that could become the seventh named storm of the hurricane season – TS Gonzalo. It is about 280 miles east of Antigua and has the potential to cause storm-force winds across the island and the rest of the northeast Caribbean. Click link for more





Japan and India Braced for Tropical Cyclones

9 10 2014

Typhoon Vongfong is said to have reached peak winds of 180 mph. In comparison with the Atlantic Basin, only Hurricane Allen of 1980, Hurricane Gilbert of 1988 and Hurricane Wilma of 2005 have had stronger sustained winds.

Official blog of the Met Office news team

Last weekend Typhoon Phanfone brought strong winds and heavy rain to many parts of Japan causing damage and disruption to travel. Japan is now preparing for another typhoon which could be just as disruptive, if not more so.

Typhoon Vongfong has been gathering strength and moving slowly across the western Pacific all week and has become the strongest tropical cyclone to have occurred anywhere in the world since the devastating Typhoon Haiyan which struck the Philippines last November. At its peak Vongfong was estimated to have sustained winds near 180 mph and a central pressure of 900 mb.

Forecasts for Typhoon Vongfong have been very consistent and predict that it will firstly cross some of the Ryukyu Islands of Japan at the weekend. The typhoon will then turn north-eastwards and cross Japan’s main islands at the beginning of next week starting with Kyushu in the south-west. At that time Vongfong…

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7-Day Forecast for Antigua and Barbuda

3 10 2014

Dale C.  S. Destin |

Here is my first 7-Day forecast for Antigua in over a year. It was postponed due to my pursuit of advance studies in climate and society. However, I am back, and from here on in, the forecast will be issued (for now) twice weekly – Mondays and Fridays.

7-DayWxFcst

Mostly fair and hazy skies will take place for the weekend. The chance of showers is near 0%. This is excellent weather for outdoor activities but very miserable weather for the agricultural community and water resource managers among others. It is very unusual for October, the wettest month of the year to be having this many consecutive dry days. However, the same atmospheric conditions suppressing the hurricane season also cause below normal rainfall.

The rest of the forecast calls for a moderate chance of showers, day or night.  Notwithstanding, these days will be fairly dry as not more than one mm is anticipated for each day.

Seas are going to remain excellent for sea bathing, power boating and most marine activities but perhaps less than ideal for sailing. Waves will be less than 1.2 m or less than 4 feet while the winds are going to be moderate through Sunday and light thereafter. Light winds will generally allow for a bit warmer days and cooler night, particularly on Tue, Wed and Thu next week.

Enjoy the weather and have a great weekend!





Tropical Wave Caused Storm Force Winds

3 10 2014

Dale C. S. Destin |

The very quiet hurricane season was brought to life last night across the southern Caribbean by an unsuspecting tropical wave. The rather weak wave caused storm force gusts across Trinidad and Tobago, Grenada, St. Lucia, St. Vincent and Barbados. The strongest winds were reported across Barbados were there was a gust of 62 mph around midnight, 12 mph shy of hurricane force.

The tropical wave has caused a surge in the low level winds across the area. Added to the surge are apparently superimposed downbursts/macrobursts associated with periods of heavy thunderstorms and downpours. These downbursts are what were mainly responsible for the strong destructive winds.

Roof Damage. Photo by Marvin Arneaud via The Trinidad Guardian Newspaper

Roof Damage. Photo by Marvin Arneaud via The Trinidad Guardian Newspaper

Reports out of Trinidad and Barbados indicate that a number of homes have been damaged in those islands. According to the Trinidad Guardian, 25 homes lost roofs within the precincts of Diego Martin, Petit Valley, Tunapuna and Sangre Grande, Trinidad. Many homes also lost electricity. Early reports out of Barbados indicate that homes there also experienced roof damage. The extent of the damage is unclear especially for Barbados and the rest of the southern Caribbean.

ASCATThis morning, an image from the ASCAT satellite, which has the ability to measure surface winds among other things, showed that further strong winds are likely as the wave has winds of around 35 mph near its axis currently moving through the southern islands.

Currently, showers and thunderstorms are being experienced in many places of the southern Caribbean. In some places, it is quite heavy. A few places are having storm force gusts i.e. gusts in excess of 34 mph.

 

 

Radar Image

Radar Image

 








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