Drought Worsens to Serious Levels

20 04 2021

Dale C. S. Destin |

With continued below normal rainfall through March, the meteorological drought has worsened to serious levels for Antigua. That is the “good” news, the bad news is that the drought is likely to get worse over the next few months, as below normal rainfall is forecast by most models.

WMO Lead Centre for Long-Range Forecast Multi-Model Ensemble is forecasting 60-70% likelihood of below normal rainfall for Antigua and Barbuda; only two of the 12 models forecast near normal rainfall. Also, below normal rainfall is likely for much of the Caribbean Basin.

This is the driest start to a year since 2015 and the ninth driest first-quarter for Antigua in a series that dates to 1928. The island-average rainfall of 93.0 mm (3.66 in) represents only 57 percent of the normal total for January to March (JFM); hence, 43 percent of the regular flow of water from our skies was missed by our plants, catchments, economy and ecosystems.

The rainfall for March of 29.2 mm (1.15 in) is the worst for the month since 2015. The total was only 63 percent of the usual amount for the first month of spring; hence, a significant deficit of 37 percent.

There is no discernible respite in the foreseeable future. The vast majority of models are forecasting deficit rainfall to be the order of the next six months. Thus, the drought is likely to get worse. Our catchments could again revert to mud patches and or grasslands, which has virtually become an annual phenomenon.

Other droughts generally lag a meteorological drought; however, it is evident from our catchments that agricultural, hydrological and ecological droughts, to some degree, are occurring or imminent. There is also the concern that this may precipitate a socio-economic drought. Our utilisation of the ocean around us for fresh water has made us resilient; notwithstanding, there are still likely to be notable impacts, direct and indirect, when the other droughts get underway in earnest.

The water authority, the Antigua Public Utilities Authority (APUA), has already signal an end to surface water to occur in a few months, that is even more likely than when it was said over a month ago, as rainfall for April has been virtually absent, thus far. Water rationing is imminent, if not already occurring.

Antigua is not alone in experiencing significant first-quarter rainfall deficits. Much of the Eastern Caribbean is having a similar thirst for rainfall. Short and long-term droughts continue to evolve across many places, and it is probable that the shortfall is precipitation will worsen and or spread to most of the Basin over the upcoming months.

Exert from the Caribbean Climate Outlook Forum (CariCOF) Drought Outlook for March 2021

Please continue to follow me for more on this evolving drought and all things weather and climate via TwitterFacebook and Instagram. Also, share this blog, if you found it useful. 

2021 Atlantic Hurricane Season Early Forecast

12 04 2021

Dale C. S. Destin |

We could have a repeat of the record breaking 2020 Atlantic Hurricane Season this year. My early forecast for the 2021 Season is out, and it calls for above normal activity being likely. It predicts the most likely number of named storms (tropical storms and hurricanes) to be 21; however, there is a 70 percent or high confidence of the number ranging between 17 to 30. Recall that we had an unprecedented 30 named storms last year.

My forecast also calls for an accumulated cyclone energy (ACE) index of 184 with a high confidence of the range being 109 to 275. The ACE for the 2020 Season was 185; just one more than is forecast for this year. Also predicted are nine hurricanes with a 70 percent confidence of  the total being 6 to 14 and 5 major hurricanes with high likelihood of a range of 2 to 7.

If this forecast pans out, this season would be the third most active since 2005, in terms of ACE, and the 11th most active in the series dating back to 1851. It would also be ranked third for the highest number of named storms and tied for 11th and 17th for the most major hurricanes and hurricanes respectively.  

According to other forecasts surveyed, the average is for an ACE of 151, 18 named storms, 9 hurricanes and 4 major hurricanes, an above normal season. This is generally consistent with my forecast but with a notable 22 percent less activity (ACE). Notwithstanding, I am very confident in the forecast; last year, my forecast consistently called for more storms than virtually all else and was the only one that indicated that the 2005 record could be broken and that we could get 30 or more named storms. However, regardless of the forecast, you should always prepare the same each season, as it only takes one hurricane to ruin your year and or life.

Accumulated Cyclone Energy (ACE) based on 6 forecasting entities.

Recall that the ACE is the universally accepted metric used to classify the overall activity of a hurricane season. It takes not only the number of named storms into consideration but also their intensities and duration. For example, the 2020 season had a record 30 named storms, eclipsing the record of 28 set in 2005; despite this, the ACE of 185, ranked it as the 10th most active season, eight spots behind 2005, which had an ACE of 250 and nine spots behind 1933–the record most active season with an ACE of 259. With respect to some other notable records, 2005 still holds the record for the most hurricanes with 15, and remains tied with 1961 for the highest number of major hurricanes–7.

The main reasons for the above normal forecasts are the likely above normal sea surface temperatures across the tropical North Atlantic and a cold-neutral El Niño Southern Oscillation (ENSO) during August to October–the peak of the hurricane season.

A typical season, based on the standard climate period 1981-2010, has 12 named storms, 6 hurricanes and 3 major hurricanes. Major hurricanes have sustained wind speeds of at least 178 km/h or 111 miles per hour (e.g., Category 3 or higher), according to the Saffir Simpson Hurricane Wind Scale. The last Atlantic hurricane season–2020, will be most remembered for the record 30 named storms with Major Hurricanes Laura, Delta, Eta and Iota. Collectively, they accounted for over 300 of the over 400 deaths from tropical cyclones and caused over US$32 billion of the US$51 billion in damage. The season also produced 13 hurricanes and 6 became major hurricanes.

Satellite images for all 30 named storms from the 2020 Atlantic Hurricane Season. Credit WMO

This forecast will be updated monthly around the 10th of each month until August. The first update will be issued around May 10.

The Atlantic hurricane season officially begins on June 1 and concludes on November 30; nevertheless, in the last five years, there have been preseason tropical cyclones–be prepared!

Please share this blog, if you found it useful and follow me for more on the upcoming hurricane season, which unfortunately could be a repeat of last year, for and all things weather and climate – TwitterFacebook and Instagram.

%d bloggers like this: