2nd Driest May on Record, Serious Drought Continues

23 06 2021

Dale C. S. Destin |

We have just witnessed the second driest May, in Antigua, on record dating back to 1928. It was also the bottom 10 driest March-May and the bottom 4 driest January-May. With such significant rainfall shortage, the meteorological drought continues for Antigua, with a return to serious intensity. Much of the drought impacts are being mask; notwithstanding, the country is feeling it deep in the pocket and models indicate that this will continue for much of the upcoming three months.

WMO Lead Centre for Long-Range Forecast Multi-Model Ensemble is forecasting 50-60% likelihood of below normal rainfall for Antigua and Barbuda. Also, below normal rainfall is likely for much of the Caribbean Basin.

The rainfall for May was 17.3 mm (0.68 in), the lowest since 2001, when the country had 6.4 mm (0.25 in). The total for the month was almost unimaginably low at 17 percent of the normal of 101.1 mm (3.98 in). Only eight other Mays have had less than an inch of rain. Overall, it was the 13th driest month of all 1121 on record.

The meteorological spring, March-May, was also very dry. The total of 85.3 mm (3.36 in) was the ninth lowest for the season. The last time we had a drier spring was 2015.  

We continue to witness one of the driest years on record and easily the driest since 2015. The year-to-date total is a meagre 149.1 mm (5.87 in), only 44 percent of the usual rainfall of 341.6 mm (13.45 in). The absent rainfall, 192.5 mm (7.58 in), is more than the annual average for January, February and March combined. Only three other years have had a drier start: 2015 with 140.2 mm (5.52 in); 2001 with 113.0 mm (4.45 in) and 1939 with 131.8 mm (5.19 in).

Our last wet month was November, which was floodingly wet. Since then, the last six months, December-May, is the fourth driest on record and the lowest since 2015. The period has only yielded 53 percent of normal rainfall. Our drying catchments and thirsty brownish landscape bear witness to the missing rainfall.

The upcoming season, July to September, is likely to be drier than normal. The majority of models are forecasting the continuation of deficit rainfall. Hence, the drought is likely to continue. Our largest catchment, Potworks Dam, along with others, could again revert to dry lands and shortcuts for vehicular traffic.

Based on models which correlate our sea surface temperatures, across the tropics, with our rainfall, the medium and long term continue to look brown. This dry season, January-June, is expected to be among the five driest on record. Meanwhile, the year is likely to be drier than usual with a 58 percent chance of below normal rainfall; this is up 12 percent from last month. There is a non-trivial 18 percent probability of the year’s rainfall falling in the bottom 10 percentile.

As the meteorological drought goes or worsens, so go or will the other droughts: agricultural, hydrological and ecological. There is also the growing concern that this may precipitate a socio-economic drought, if it has not already done so. Our utilisation of the ocean around us for fresh water has made us resilient; however, at a very high cost, as potable water from this source cost at least seven times that from surface and ground water.  

Potworks Dam is close to falling below extraction levels. With the rainfall outlook bleak, we could be out of surface water in weeks. Water rationing is imminent, if not already occurring.

Antigua is not alone in experiencing significant rainfall shortages. Much of the Eastern Caribbean remains  thirsty for rainfall. Deficit rainfall is occurring across many places, and it is probable that the it will worsen and or spread to other islands, over the upcoming months, based on recent forecasts, particularly the central Windward Islands to the Dominican Republic. For May, most of the Caribbean Basin had less that 50 percent of the usual rainfall, with some areas receiving less than ONE percent.

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. 

June Updated Forecast for the 2021 Atlantic Hurricane Season

19 06 2021

Dale C. S. Destin |

The numbers for this hurricane season are likely to be very high once again. My updated forecast for the 2021 season is out, and it continues to call for an above normal season being likely. The confidence of an above normal season has grown from 69 to 78%. It is also possible that the season could be super hyperactive with more than 19 named storms likely.

The prediction is still for 22 named storms (tropical storms and hurricanes), with a 70 percent confidence or high confidence of the number ranging between 17 to 28. It is also likely–56 percent chance (down 2), that the number of named storms will exceed 19 and be in the top 10 percentile of the historical record, dating back to 1851.

My forecast also calls for an accumulated cyclone energy (ACE) index of 186 (up 7) with a high confidence of the range being 112 to 286. There is also a 44 percent chance (up 9) of the ACE index exceeding 223. Also predicted are 9 hurricanes (down 1) with a 70 percent confidence of  the total being 6 to 13, and 5 major hurricanes (up 1) with high confidence of 2 to 7.

If this forecast pans out, this season would be the most active since 2017, in terms of ACE, and the 10th most active on record 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 hurricanes and major hurricanes respectively.

The main reasons for the above normal forecasts are the likely above normal sea surface temperatures across the tropical North Atlantic and a weak La Niño and or 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 1991-2020, has 14 named storms, 7 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.

This forecast is updated monthly around the 15th each month until August. The next update will be issued around July 15.

The Atlantic hurricane season officially began on June 1 and will conclude on November 30. Be prepared! Please share this blog, if you found it useful and follow me for more on the ongoing hurricane season, which unfortunately could be another wild one, and for all things weather and climate – TwitterFacebook and Instagram.

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