More Drought Quenching Rainfall for Antigua

17 12 2014

Dale C. S. Destin |

Surface chart showing stationary front across northern Caribbean (red & blue)

Surface chart showing stationary front across northern Caribbean (red & blue)

More drought quenching rainfall fell today across Antigua yesterday December 16. A near stationary front (shown below on the surface chart) showered the island with much needed water. At the V. C. Bird International Airport (VCBIA), 10.9 mm of rain was measured, all falling between 2:45 pm and 6:45 pm. However, estimates from weather radar (shown below) indicate that as much as 50 mm may have fallen on northern side of the island. Over in Barbuda, a drenching 150 mm or more fell according to radar estimates. Going by what was actually measured by raingauge, at the VCBIA, the rainfall total now stands at 69.7 mm (2.74 in). This means that the Airport, thus far, has received near normal rainfall for December. However, above normal rainfall, above 91.4 mm (3.6 in) is forecast for the month. Thus, further quenching of the drought is anticipated.

Radar rainfall estimates

Radar rainfall estimates

The front did not just affect Antigua; satellite photo and TRMM data below show the cloud and rainfall signature patterns of the system stretching across much of the northern Caribbean from the Leeward Islands west to Jamaica and parts of Cuba.

 

Satellite picture of the stationary front

Satellite picture of the stationary front

Here are the rainfall totals reported by some of the other affected islands:

  • Robert L. Bradshaw International Airport, St. Kitts – 39 mm
  • Luis Muñoz Marín International Airport, Puerto Rico – 101 mm
  • Sangster International Airport, Jamaica – 38 mm
TRMM rainfall estimates

TRMM rainfall estimates

Rainfall at the VCBIA continues to run above normal for December. Exceeding 100 mm is a real possibility. If this were to happen, it would be the fourth time in the last five years. Continue to think rain.

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Flying Start to December’s Rainfall for Antigua

7 12 2014

Dale C. S. Destin |

There has been a flying start to the rainfall total for Antigua for December. So far for the month, December 1-5, the rainfall total at the V. C. Bird International Airport is 50.4 mm (1.98”). This is well above normal, the fifth highest on record dating back to 1967 and the second highest since 1981. Relative to this period, only December 1-5, 2012 has been wetter with 57.0 mm (2.24”), in the past 34 years. On average at the Airport, December 1-5, gets 12.6 mm.

A large portion of the rainfall, so far for the month, was due to a deep layer trough system connected to a low pressure area, which formed hundreds of miles north of Antigua. The trough and low are still around; however, not much more rainfall is anticipated as moisture levels are near minimum.

In 48 years, only four other December 1-5 were wetter: 2012, 1981, 1970 and 1968. The record wettest December 1-5 occurred in 1970, when a staggering 114.0 mm of rain fell.

Dec1-5_Rain_GraphicThis very wet start to December has thankfully further quenched the drought, which started in September 2013; however, it is no yet over. The last assessment of the drought indicates that it has eased to slight levels. At least a further 60 mm would bring it to an end.

Will we get the needed amount of rainfall to end the drought? It is not very clear as the climate continues to send mixed signals. The spike in rainfall over the past couple of months seems to be partially due to warmer than normal North Atlantic sea surface temperatures. However, an El Nino appears to be brewing, and if established, could suppress rainfall. Notwithstanding, the forecasts for December and the period December to February (“winter”) are for above normal to normal rainfall. Thus, it is likely that the drought will end or not get any worse.

Of course, while the 50.4 mm so far for December is impressive and invaluable, it does not tell us where the month will end up overall, and there is a slight chance of the upcoming months having below normal rainfall. On average at the Airport, the rest of December gets 71.2 mm (2.80”) of rainfall. In the past this period has had as little as 14.5 mm (0.57’’) and as much as 207.3 mm (8.16”).

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