August 2016 to January 2017 Climate Outlooks for Antigua and Barbuda

16 08 2016

Dale C.S. Destin |

The August 2016 to January 2017 climate outlooks are now available for Antigua and Barbuda. Over the short, medium and long-term the rainfall is likely to be above to near normal.  Thus, there is a moderate chance of, at least, a temporary end to some droughts over the upcoming six months. Meanwhile, uncomfortably warm temperatures are expected for the upcoming six months. August-October (ASO) is the most active part of the hurricane season and is likely to be the most active since 2012.

Drought

July 2016 was wetter than the last three Julys and wetter than the last two combined; however, it was not wet enough to end the droughts (meteorological, agricultural, hydrological and socioeconomic). We have now entered the 38th month of mostly moderate or worse rainfall deficits; however, since April, the meteorological and agricultural droughts have been at slight levels.

May-Oct2016 Rainfall Outlook

Looking forward – the meteorological and agricultural droughts could ease further or perhaps come to, at least, a temporary end as August has a 60% chance of being wetter than usual, and there is a 40% chance of the ASO period getting above normal rainfall. Over the long run, above  to near normal rainfall is likely. Notwithstanding, drought warnings and watches are in effect for various periods through January 2017.

The warm phase of El Nino Southern Oscillation (ENSO) – El Nino, came to an end in May leaving in its wake significant adverse impacts. There is now around a 60% chance of the cold phase of ENSO i.e. La Nina developing during the last third of the year or the latter half of our wet season. A few months, ago the chance of La Nina was in excess of 75%, so its chance of develop is on the decline; nevertheless, it is still more likely than not.

If you are in our part of the world – the Caribbean, a La Nina would be more than welcome. Unlike El Nino, La Nina often brings us more than usual rainfall, and with the record drought we are still experiencing, water is more precious than gold at the moment.

Unlikely, but a much wetter than normal wet season (July-December) is desperately needed to end our severe multi-year droughts.

Precipitation and temperature

Year-to-date, Antigua, on average, has had more than twice the amount of rainfall than for the same period last year. Nevertheless, we are still over 100 mm (four inches) in the “red” relative to the long-term average of 534.9 mm (21.06 in).

This up-tick in rainfall is likely to generally continue over the long-term – August 2016 to January 2017, there is a 75% probability of above to near normal rainfall. However, the projected rainfall for 2016 is 657 to 1218.5 mm (25.9-48.0 in) or below to near normal.

The summer heat is likely to continue through October with the ASO “season” likely to be warmer than usual. With a high confidence of warmer than usual weather, there is also the potential for extreme temperatures. The heat could be very distressing for many especially since both night-time and day-time temperatures are likely to be higher than usual. High than usual night-time temperatures are likely to continue through January 2017. This has negative implications for health, especially among older adults, infants and young children.

The hurricane season

Thus far for the 2016 Atlantic hurricane season, there have been five named storms and two hurricanes (Alex and Earl). The number of storms is considered above normal relative to the long-term average of three. However, the ACE, which matters most, is near normal.

Recently issued hurricane season forecasts have reasserted that the 2016 season is likely to be the most active since 2012. Notwithstanding, the forecast is for the season to fall in the near normal range with around 15 named storms, 7 becoming hurricanes and 3 major hurricanes; this includes those already formed.

Notwithstanding the forecast, we need to be fully prepared, as it only takes one hurricane to set our life and community back by decades. Be prudent: prepare for the worst and hope for the best!

See the following links for the full outlooks: August 2016, August-October 2016, November 2016-January 2017, August 2016-January 2017, Drought, 2016 Updated Hurricane Season Forecast.

The next set of outlooks will be available by September 3, 2016.

Correction, August 19, 2016: An earlier version of this article incorrectly stated the rainfall forecast for August 2016 to January 2017. The forecast is for above to near normal rainfall rather than below to near normal.





The Most Active Atlantic Hurricane Season in Four Years Remains Likely

15 08 2016

Dale C. S. Destin |

The latest round of forecasts has reaffirmed that the 2016 Atlantic hurricane season is likely to be the most active since 2012. However, notwithstanding the predicted increase in activity over recent years, the forecast continues to call for a near normal 2016 hurricane season.

Ensemble forecast

Our ensemble (mean) forecast calls for 15 named storms with 7 becoming hurricanes and 3 reaching major hurricane status. This represents a slight difference from the previous forecast, which called for one less named storm but one more major hurricane.

Updated Hurricane Season Forecast

In meteorological community, the accumulated cyclone energy (ACE) index is deemed the best “yard-stick” to measure the activity of a hurricane season. The ACE index is a measurement of the strength and duration of a named storm. Summing together the ACE of each named storm, provides a more comprehensive picture of the activity of a season, aside from just the number of storms.

This year, our ensemble forecast calls for an ACE index of 102. This is seven less than the previous forecast ACE but still well within the near normal range. If this forecast pans out, the 2016 season would be around 183%, 52% and 62% more active than 2013, 2014 and 2015 respectively.

The ensemble (mean) forecast is based on predictions from seven organizations: Klotzbach of Colorado State University, the U.S. National Oceanic and Atmospheric Administration (NOAA), Saunders and Lea of Tropical Storm Risk.com (TSR), the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF), Weather Channel, the Institute for Meteorology (INSMET) of Cuba and Truchelut of WeatherTiger.

The season so far

So far, there have been five named storms: Hurricanes Alex and Earl and Tropical Storms Bonnie, Collin and Danielle. None impacted Antigua and Barbuda, but the disturbance that became Earl brought us some welcome showers. The season officially began June 1 and runs until November 30. However, no one told that to Alex and Bonnie – the former developed in January and the latter in May. With five named storms gone, around 10 more are likely.

Uncertainty

The skill in forecasting the hurricane season in August is quite high – up to 50% better than guessing or using the average activity of a season as the forecast, which would be correct around 33% of the time. This translates to the August forecast being right around 83% of the time.

Notwithstanding the high skill, there is and always will be some level of uncertainty. It is still uncertain as to if and when will La Nina (cooler than usual Pacific Ocean) develop. Also, there are uncertainties regarding it strength, if it does develop. A strong La Nina during August to November could result in an active/above normal season as opposed to a near normal one. NOAA has put the probability of an active season at 35% and the probability of a near normal one at 50%.

Probability of Antigua and Barbuda being hit

According to Klotzbach, the likely best similar years to this hurricane season are 1958, 1959, 1966, 1978, 1992 and 1998. Of these years, six named storms passed within 121 miles of Antigua; of them, there were three hurricanes and one tropical storm that hit the island. Of them, Major Hurricane Georges of 1998 is the most notable. Thus, based ONLY on similar years, probabilistically Antigua has a

  • 63% chance of being affected by one or more named storms (passing within 121 miles), usually it’s 62%;
  • 49% chance of being hit by one or more named storms (passing within 17 to 75 miles), usually it’s 49% and
  • 39% chance of being hit by one or more hurricanes (passing within 17 miles), usually its 31%.

 Barbuda’s numbers, based on five named storms passing within 75 miles:

  • 57% chance of being affected by one or more named storms (normally it’s 52%);
  • 57% chance of being hit by one or more named storms (normally it’s 32%) and
  • 39% chance of being hit by one or more hurricanes (normally it’s 23%).

The hit forecast probabilities for Barbuda are significantly higher than usual. The numbers suggest that Barbuda is more likely than not to be hit by a named storm. The other forecast probabilities are similar to what is usual. However, it must be noted that our usual numbers are generally higher than most places.

Become hurricane strong

Notwithstanding the forecast, active or inactive season, it only takes one hurricane to turn your life upside-down, so the same comprehensive preparations are required to mitigate or reduce the impacts a tropical cyclone. Take actions today and become hurricane strong/resilient. Actions include:

  • Determining your risk from tropical cyclones;
  • Developing an evacuation plan;
  • Securing an insurance check-up;
  • Assembling disaster supplies;
  • Strengthening your home;
  • Identifying trusted sources of information for a hurricane event and
  • Having your written hurricane plan.

Recall – an ounce of prevention is better than pound of cure!

A summary of the hurricane season will be available by December. Follow us via our social media platform and stay updated on the current hurricane season. We are available on twitter, facebook, wordpress, instagram, tumblr, and google+. Follow us also for all things weather and climate.





June to November 2016 Climate Outlooks for Antigua and Barbuda

9 06 2016

Dale C. S. Destin |

The June to November 2016 (summer and autumn) climate outlooks are now available for Antigua and Barbuda. We are optimistic that some droughts will come to an end over this period. Meanwhile, uncomfortably warm temperatures are expected for the upcoming six months. June to November is also the Atlantic hurricane season; it is likely to be the most active since 2012.

Drought

May 2016 was wetter than last year’s; however, it was still a relatively dry May – the second driest in nine years. Hence, the droughts (meteorological, agricultural, hydrological and socioeconomic) continue across Antigua and Barbuda. We are now entering the 36th month of mostly moderate or worse rainfall deficits.

Looking forward – some droughts are likely to ease. At worst, slight meteorological and agricultural droughts will exist at the end of the March-August and December 2015-November 2016 periods. Meanwhile, a moderate drought or worse is possible at the end of the January-September 2016 period.

ProjectedRainfall_Mar-Aug2016

The warm phase of El Nino Southern Oscillation (ENSO) – El Nino, is expected to end in weeks and a transition to the cold phase of ENSO – La Nina, is expected during our wet season – July to December. This is good news for us in that La Nina, unlike El Nino, generally encourages rainfall across our area, mainly during the wet season. This is one of the main reasons why we are optimistic about the possibility of drought ending rainfall over the next six months, if not sooner.

However, there is some caution with our optimism as La Nina is not guaranteed nor are its normal positive impacts on our rainfall. Further, the strength of the La Nina is highly uncertain. A strong La Nina favours more rainfall, whereas a weak one favours less.

Precipitation and temperature

Over the coming three months – June to August (JJA), above to near normal rainfall is expected. This could result in the meteorological and agricultural droughts coming to an end or at worse be at slight levels at the end of the period. Unfortunately, these rains are unlikely to end the more serious hydrological and socioeconomic droughts; these will likely continue at moderate or worse levels.

September to November (SON) is also expected to have above to near normal rainfall. SON is on average our wettest “season”, accounting for nearly 40% of our yearly rainfall. Thus, if this forecast pans out, all droughts would be significantly eased, if not end. This is especially true if the JJA forecast holds true also.

So far, 2016 is about 70% wetter that last year, but it’s still much drier than normal. It is now almost certain that the dry season (January-June) will be drier than usual for the third consecutive year.

The summer heat is likely to be on, as warmer than usual temperatures are forecast for June to August. With high confidence of warmer than usual weather, there is also the potential for extreme temperatures. The heat could be very distressing for many especially since night-time temperatures are likely to be higher than usual. This has negative implications for health especially among older adults, infants and young children.

The hurricane season

Relative to the last three years, we are likely to have the most active Atlantic hurricane season since 2012. Notwithstanding, the forecast is for the season to fall in the near normal range with around 14 named storms, 7 becoming hurricanes and 4 major hurricanes.

MayJuneHurricaneSeasonForecast

Like our wet season, the great determinant of the hurricane season is ENSO. El Nino tends to suppress tropical cyclone (depression, tropical storm, hurricane) activity, while its sister-phenomenon – La Nina, does the opposite. Hence, the eventual activity of the season is largely dependent on the strength of La Nina which is quite uncertain, at this time. Stronger La Ninas tend to favour more active seasons than weaker ones.

For Antigua and Barbuda, the probability of a named storm (tropical storm or hurricane) affecting the islands during an active season is quite high (around 74%) and much higher than during a normal or quiet season, with around 59% and 26% probabilities respectively. Meanwhile, the probability of us being affected by a hurricane during an active season is around 49% as opposed to 18% in a normal one and 10% in a quiet one.

Irrespective the kind of Atlantic hurricane season that occurs, we need to be fully prepared, as it only takes one hurricane to set our life and community back by decades. Prepare for the worst and hope for the best!

See the following links for the full outlooks and more: JuneJune-August, September-NovemberJune-November 2016Drought, 2016 Hurricane Season Forecast.

The next set of outlooks will be available by July 3, 2016.





The Most Active Atlantic Hurricane Season in Four Years Likely

4 06 2016

Dale C. S. Destin |

After a hat-trick of quiet Atlantic hurricane seasons, the latest round of forecasts is pointing to the most active season since 2012. However, notwithstanding the projected increase in activity over recent years, the forecast is for the 2016 hurricane season to be near normal.

Ensemble forecast

Our ensemble (mean) forecast calls for 14 named storms with 7 becoming hurricanes and 4 reaching major hurricane status. This represents an increase over the previous forecast for the season of one named storm and one hurricane.

MayJuneHurricaneSeasonForecast

In the tropical cyclone community, the accumulated cyclone energy (ACE) is the indicator used to determine the activity of a hurricane season. The ACE index is a measurement of the strength and duration of a named storm. Summing together the ACE of each named storm, provides a more comprehensive picture of the activity of the season, aside from just the number of storms.

This year, our ensemble forecast calls for an ACE index of 109, which is near normal. If this forecast pans out, the 2016 season would be around 200%, 63% and 73% more active than 2013, 2014 and 2015 respectively.

The ensemble (mean) forecast is based on predictions from Klotzbach of Colorado State University, the U.S. National Oceanic and Atmospheric Administration (NOAA), Saunders and Lea of Tropical Storm Risk.com (TSR), the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF), UK Met Office, the Hurricane Genesis & Outlook (HUGO) Project of Coastal Carolina University and the Institute for Meteorology (INSMET) of Cuba.

Uncertainty

It must be noted though that the skill in forecasting the hurricane season (June to November) in May/June is moderate. However, it is the best available on earth, and it continues to improve.

Apart from the inherent limits to our skill in forecasting the season, this year, there is the huge uncertainty of the eventual strength of La Nina (the coolness of the tropical Pacific Ocean). A strong La Nina could result in a more active season than is forecast, with the converse being true.

Probability of Antigua and Barbuda being hit

According to Klotzbach, the likely best similar years to this hurricane season are 1973, 1978, 1983, 1992 and 2003. Of these years, we were only hit by Tropical Storm Christine of 1973. Thus, based ONLY on similar years, the probability of Antigua being hit this year by one or more named storms is around 18%, while the probability of one or more hurricanes is 0%.

In general, the probability of Antigua being hit by one or more named storms annually appears to vary according to the phase of the Atlantic. During the quiet phase of 1962 to 1994, the probability of one or more named storms was around 26%, while the probability of one or more hurricanes was around 14%. Meanwhile, for the active phase of 1995 to present, which may have come to an end, the probability of one or more named storms increased to around 55%, while the probability of one or more hurricanes is around 35%.

Overall, based on the climatological period of 1981-2010, the probability of being hit by one or more named storms is around 49% (every 2 years on average), while the probability of one or more hurricanes is around 31% (every 3 years on average). Barbuda has similar numbers.

Become hurricane strong

Notwithstanding the forecast, it only takes one hurricane to change your life and community, so the same comprehensive preparations are required every year. Become hurricane strong by taking actions today to become hurricane resilient. This includes:

  • Determining your risk from tropical cyclones;
  • Developing an evacuation plan;
  • Securing an insurance check-up;
  • Assembling disaster supplies;
  • Strengthening your home;
  • Identifying trusted sources of information for a hurricane event and
  • Having your written hurricane plan.

Recall – an ounce of prevention is better than pound of cure!

We will publish an undated ensemble forecast by early August, just before the traditional peak of the hurricane season. This forecast is generally the most skilful; it will have much reduced uncertainty.

2016 Atlantic Tropical Cyclone Names

Follow us via our social media platform and stay updated on the 2016 Atlantic hurricane season. We are available on twitter, facebook, wordpress, instagram, tumblr, and google+. Follow us also for all things weather and climate.





Record Warm February Nights Contribute to Record-Tying First Third Night-Time Heat Across Antigua

27 05 2016

Dale C. S. Destin |

Although the mean air temperature for the first third of the year – January to April, was near normal, night-time temperatures, as expressed by the mean minimum temperature, were at record-tying levels across much of Antigua.

For the first third, at the V. C. Bird International Airport (VCBIA), the mean minimum temperature of 23.5 °C (74.3 °F) equalled the record highest, tying that of 2010 and 1969. The long-term average minimum for January to April is 22.7 °C (72.9 °F).

At the same location, the mean minimum temperature for February was 23.4 °C (74.1 °F). This shattered the previous record of 22.2 °C (72.0 °F) for the month. The mean minimum for the other months, in the period, ranked in the top ten of the record dating back to 1969.

As has been observed globally, colder places, and in our case, colder times are warming faster than warmer times. On average, the first third of the year has the lowest mean minimum temperature; yet, it is warming at a faster rate than the other warmer two thirds (May-August, September-December) of the year – it is warming at a statistically significant rate of around 1.3 °C (2.34 °F) per hundred years.

MeanMinTemp

The blue straight line is the long-term temperature trend line

Regarding rainfall, for the first time in three years, we got our traditional April showers. The 1981-2010 long-term-average is 85.6 mm (3.37 in), and we got 79.0 mm (3.11 in), just 8% less than the average. Seatons Village and nearby areas were, however, quite wet with rainfall totals in excess of 150 mm (6 in). On the drier end of the spectrum were Five Islands and nearby areas with 34.3 mm (1.35 in).

Notwithstanding April’s rainfall, during the first third of the year the island-average rainfall for Antigua was below normal. However, it’s the highest in three years. Year-to-date, we have recorded 200.9 mm (7.91 in) of rainfall. This is 60.7 mm (2.39 in) below the long-term-average.

FirstThirdRainfall

The light blue straight line is the long-term rainfall trend line

Overall, annual rainfall is on an insignificant downward trend. Meanwhile, there is virtually zero change taking place with the rainfall for the first third of the year. However, April is getting wetter at a statistically significant rate of around 45.0 mm (1.77 in) per hundred years.

See our temperature and precipitation statements for more.

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Become Hurricane Strong by Taking Action Now

15 05 2016

Dale C. S. Destin |

The 2016 Atlantic hurricane season starts in 17 days – June 1, and runs until November 30. The season is forecast to have near normal activity – 13 named storms, 6 hurricanes and 3 major hurricanes.

Regardless of the forecast, the same detailed preparations are required to protect life, property and livelihoods. As we say in the meteorological community, it only takes one to change your life and community. Recall, notwithstanding last year’s hurricane season being quiet, Erika caused catastrophic damage to Dominica.

May 15-21 is designated hurricane preparedness week in the U.S. – the time to prepare for potential tropical cyclones (tropical depressions, tropical storms and hurricanes) over the upcoming six months. We have no such week here, but we have a shared enemy; hence, we need to prepare similarly. The following are the seven actions required now to become “hurricane strong” i.e. resilient to tropical cyclones.

Determine your risk from tropical cyclones. Disaster risk is inversely proportional to knowledge – meaning the more knowledge you have on the subject the lower your risk is likely to be. Depressions, storms and hurricanes are not just about high winds, other associated hazards are inland flooding, storm surge, rip currents and tornadoes. Know the potential hazards that could affect your location and prepare to mitigate them. Local knowledge could be crucial in this regard, so seek it, especially with respect to flooding (See our tropical cyclone climatology).

All Antigua Named Storms

All the named storms to have affected Antigua – 1851-2014. Credit NOAA

Develop an evacuation plan if you live in an area that will need to be evacuated or if your home is deemed unsafe to ride out a tropical cyclone. Public shelters should be a last resort, so try to arrange to have the home of a friend or relative as your evacuation destination, if need be.

Secure an insurance check-up to ascertain that you have adequate coverage for your home and content. You especially need to ensure that you have coverage for wind and flood damage – the two main destructive hazards of depressions, storms and hurricanes.

Assemble disaster supplies now so as to avoid long lines and potential scarcity before and after a tropical cyclone. This is one of the most important elements of being “hurricane strong”. Supplies should be enough to last for at least one week after the event and should include things such as non-perishable food items, water, portable radio and batteries.

Strengthen your home, if possible, to be able to withstand, at least, a Category 3 hurricane. The best place to ride out a storm is in your own home. So, if you have questions about its strength, get a qualified professional to evaluate it, and if it can be retrofitted, do it. In the long run, it will be far cheaper than going to a shelter and leaving your property to be blown away.

Identify your trusted sources of information for a hurricane event. Your national meteorological service is your most trusted source – in the Antigua and Barbuda context, it’s the Antigua and Barbuda Meteorological Service through its website and hotline: 4634638.

Trusted information can also be had from the following social media accounts:

Your disaster management agency, in our case – the National Office of Disaster Service (NODS) will provide disaster management services to reduce the risk of the inclement weather.

Both your met office and disaster management agency will partner with a number of media outlets to get the information out. For us, the Antigua and Broadcasting Service (ABS) will be foremost partner.

Complete your written hurricane plan now, before the hurricane season starts. The time to write your plan is not when you are steering down the barrel of a hurricane. Under such conditions, you are likely to forget crucial things or make the wrong decisions. Your written plan should include where you are going to ride out the storm and a communication strategy.

Start preparing for the hurricane season today and become “hurricane strong”. Follow us via social media for the latest updates.





May to October 2016 Climate Outlooks for Antigua

3 05 2016

Dale C. S. Destin |

The May to October 2016 climate outlooks are now available for Antigua. In the short-term, the news remains bleak regarding rainfall. However, in the long-term, there is relieving news, as above normal rainfall is likely for the period August-October. Meanwhile, uncomfortably warm temperatures are expected for the upcoming six months.

Drought

Notwithstanding a wetter than normal week in April, droughts (meteorological, agricultural, hydrological and socioeconomic) continue across Antigua. We are now entering the 35th month of mostly moderate or worse rainfall deficits.

Currently, a moderate drought or worse is evolving over the periods – February to July 2016, October 2015 to August 2016 and November 2015 to October 2016. All three periods are likely to have below normal rainfall. Drought warnings remain in place and will likely continue into the third quarter of the year.

Feb-July2016_Rainfall

The current El Nino looks to be on its last gasp. It will transition to a neutral state around the middle of the year and possibly to La Nina during our wet season. La Nina, unlike El Nino, generally encourages rainfall across our area, mainly during the wet season. Although still distant, we appear to be drawing nearer to the light at the end of the tunnel i.e. the end of the droughts.

Precipitation and Temperature

Over the coming three months – May to July, below to near normal rainfall will result in the droughts continuing, at best, slight, and at worse, re-intensifying to serious levels.

Meanwhile, August to October will likely see above normal rainfall. Thus, some droughts may come to an end during the latter half of the upcoming rainy season. However, there remain large uncertainties as to how wet the rainy season will eventually be.

So far, 2016 has been wetter that last year; however, it’s running over 50 mm (2 in) below average. The dry season (January-June) is likely to be drier than usual, and at best, the year will have near normal rainfall.

The heat will likely be on for much of the rest of the year. Warmer than normal temperatures are probable for MayMay-July and August-October.

See the following links for the full outlooks; rainfall: MayMay-July, August-OctoberMay-October 2016 and April Drought Outlook.

The next set of outlooks will be available by June 3, 2016.








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