Agro-Meteorological Bulletin for the Third Dekad (21st - 30th) of September, 2022



ISSUED AT: 06:09 PM

Date: Friday 23rd of September 2022

Figure 1.

Figure 2.

Summary:

Moderate to high rainfall amounts are expected on four of the fifteen days.

Four wet days with rainfall amounts ranging between 10.0 mm and 40.0 mm are expected on the 21st-24th of September, while eleven relatively wet days with rainfall amounts ranging between 1.0 mm and 9.0 mm are expected on the 25th-5th of September/October.

Trinidad:

Four wet days with rainfall amounts ranging between 10.0 mm and 40.0 mm are expected on the 21st-24th of September, while eleven relatively wet days with rainfall amounts ranging between 1.0 mm and 9.0 mm are expected on the 25th-5th of September/October. The daily rainfall totals are forecast to range between 1.0 mm to 40.0 mm across different farmlands, with fifteen-day rainfall totals ranging between 60.0 mm and 100.0 mm. The impactful rainfall events will mostly occur across the northeastern, southeastern, southwestern and northwestern parts of Trinidad. There is a high (80%) probability that flash and riverine flooding will occur during/after heavy rainfall events.

Tobago:

Similar to Trinidad, Tobago will experience four wet days with rainfall amounts ranging between 10.0 mm and 40.0 mm are expected on the 21st-24th of September, while eleven relatively wet days with rainfall amounts ranging between 1.0 mm and 9.0 mm are expected on the 25th-5th September/October.  The daily rainfall totals are forecast to range between 1.0 mm to 40.0 mm across different farmlands across the island, with fifteen-day rainfall totals averaging around 100.0 mm.

Temperatures & Winds:

The maximum temperatures are expected to remain warm, with temperatures ranging between 29.0oC to 33.0oC throughout the period. However, temperatures are expected to have a real-feel or feels-like between 32.0oC to 45.0oC on most days. The minimum temperatures will range between 23.0oC to 25.0oC during most nights/early mornings, dropping lower in rural areas and valleys.

In general, mostly weak easterly to south-easterly winds of an average speed of 10-20 km/h are expected, however gusts can reach speeds of up to 50-70 km/h especially during heavy showers. Moderate to high rainfall totals, mostly low wind speeds, warm to very warm days and warm feels-like temperatures will sustain average evapotranspiration rates in crops ranging between 1.0 to 8.0 millimeters per day.

Moisture levels:

Over the fifteen-day period across Trinidad and Tobago, moisture levels are expected to be moderate to high, with average daytime relative humidity values in the lower-60s to lower-90s, in terms of percentage.


Agro-Meteorological Bulletin for the Third Dekad (21st - 30th) of September, 2022



ISSUED AT: 06:09 PM

Date: Friday 23rd of September 2022


Definitions used in the forecast and bulletin:

Term Meaning
Dekad 10 day rainfall measuring period
Rain Day A day with 1.0 mm or more of rainfall amount
Wet Day A day with 10.0 mm or more rainfall amount
Extremely Wet Day A day with 25.0 mm or more of rainfall amount
Normal Rainfall Between 75% and 125% of the average
Below Normal Rainfall Rainfall below 75% of the average
Above Normal Rainfall Rainfall in excess of 125% of the average
Much Below Normal Rainfall Rainfall below 50% of the average
Much Above Normal Rainfall Rainfall above 150% of the average
Scanty Rainfall Less than 1 mm
Moderate Rainfall 1-10 mm
Heavy Rainfall 10-50 mm
Very Heavy Rainfall Greater than 50 mm
Probability of 1-30 % Low Chance
Probability of 30-70 % Moderate Chance
Probability greater than 70 % High Chance
Term Amount of Rain Type of day
Scanty Rainfall Less than 1 mm Relatively dry day
Moderate Rainfall 1-10 mm Relatively wet day
Heavy Rainfall 10-50 mm Wet day
Very Heavy Rainfall Greater than 50 mm Excessively wet day

Weather Bulletin for Farmers and Livestock Producers of Trinidad and Tobago for the 15-day period (21st-05th) of September/October 2022.

Date

Weather

Temperature

Heat

Real

Feel

Day Moisture

(Relative) (Humidity)

Wind

21st              

80% chance of showers

 

10.0 to 25.0 mm of   rainfall is possible

Cloudy with light/mod occasional heavy showers

Warm       Max/Min  Temperatures  oC   29.0/24.5

 

 

Feels like

29-33oC

 

 

69-90%

Weak south-easterly

15 km/h

Gust

 25 km/h

22nd   

80% chance of showers

 

10.0 to 40.0 mm of   rainfall is possible

Cloudy with light/mod occasional heavy showers

Warm      Max/Min  Temperatures  oC   29.0/23.0

 

 

Feels like

29-33oC

 

 

69-90%

Weak south-easterly

15 km/h

Gust

 25 km/h

23rd         

70% chance of showers

 

10.0 to 25.0 mm of   rainfall is possible

Cloudy with light/mod occasional heavy showers

Warm      Max/Min  Temperatures  oC   31.5/23.5

 

 

Feels like

32-36oC

 

 

69-80%

Weak south-easterly

15 km/h

Gust

 25 km/h

24th

70% chance of showers

 

10.0 to 15.0 mm of   rainfall is possible

Cloudy with light/mod occasional heavy showers

Warm      Max/Min  Temperatures  oC   32.5/24.5

 

 

Feels like

33-39oC

 

 

69-80%

Weak south-easterly

15 km/h

Gust

 25 km/h

25th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/24.5

 

 

Feels like

33-38oC

 

 

64-66%

Weak south-easterly

15 km/h

Gust

 25 km/h

 

 

26th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/24.5

 

 

Feels like

33-38oC

 

 

64-66%

Weak south-easterly

15 km/h

Gust

 25 km/h

27th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/24.5

 

 

Feels like

33-38oC

 

 

76-85%

Weak south-easterly

15 km/h

Gust

 25 km/h

28th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/25.0

 

 

Feels like

33-36oC

 

 

77-81%

Weak south-easterly

15 km/h

Gust

 25 km/h

29th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    33.0/25.0

 

 

Feels like

34-40oC

 

 

79-84%

Weak south-easterly

15 km/h

Gust

 25 km/h

30th

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/25.0

 

 

Feels like

34-40oC

 

 

75-78%

Weak south-easterly

15 km/h

Gust

 25 km/h

1st       

60% chance of showers

 

1.0 to 5.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    33.0/25.0

 

 

Feels like

34-45oC

 

 

64-70%

Weak south-easterly

15 km/h

Gust

 25 km/h

2nd

 

               

60% chance of showers

 

1.0 to 5.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    33.0/25.0

 

 

Feels like

34-45oC

 

 

64-70%

Weak south-easterly

15 km/h

Gust

 25 km/h

3rd

           

60% chance of showers

 

1.0 to 5.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    33.0/25.0

 

 

Feels like

34-45oC

 

 

64-70%

Weak south-easterly

15 km/h

Gust

 25 km/h

4th     

60% chance of showers

 

1.0 to 5.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    33.0/25.0

 

 

Feels like

34-45oC

 

 

64-70%

Weak south-easterly

15 km/h

Gust

 25 km/h

5th    

60% chance of showers

 

1.0 to 9.0 mm of   rainfall is possible

Partly cloudy with few showers

Warm      Max/Min  Temperatures  oC    32.0/24.0

 

 

Feels like

33-38oC

 

 

75-79%

Weak easterly

10 km/h

Gust

 15 km/h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Trinidad Rainfall Forecast for the 15-Day period of September/October (21st –5th) 2022.

Figure 1.  Rainfall map of Trinidad showing expected mean rainfall totals for districts across Trinidad during the 15-day period (21st-05th) September/October 2022 and percentage probability of occurrence.

Eastern, and North-Eastern areas 

Moderate chance (68%) of mean daily rainfall up to 8.8 mm.

South-Eastern areas

Moderate chance (68%) of mean daily rainfall up to 8.4 mm.

Southern areas

Moderate chance (65%) of mean daily rainfall up to 9.0 mm.

South-Western areas 

Moderate chance (68%) of mean daily rainfall up to 9.6 mm.

Central, West-Central, and inland areas

Moderate chance (68%) of mean daily rainfall up to 8.0 mm.

Northern, North-Western areas     

Moderate chance (68%) of mean daily rainfall up to 8.6 mm.

Tobago Rainfall Forecast for the 15-Day period of September/October (21st –5th) 2022

Figure 2.    Rainfall map of Tobago showing expected mean rainfall totals for districts across Tobago during the 15-day period (21st-05th) September/October 2022 and percentage probability of occurrence.

North-Eastern areas

Moderate chance (68%) of mean daily rainfall up to 10.0 mm.

South-Western areas

Moderate chance (68%) of mean daily rainfall up to 10.0 mm.

 

Sun and Moon Positions in the Sky September/October (21st –5th) 2022.

The sun is presently at 1.2 degrees North latitude and with this position, the day-length or number of sunlight hours in Trinidad and Tobago from September 21st will be 12 hours and 09 minutes, decreasing slightly to 11 hours and 59 minutes by 5th October 2022. According to the moon’s phases, the 25th (New Moon Phase)-29th of September and 2nd (First Quarter Phase)-3rd are good days for planting aboveground crops. There are no good days for planting belowground crops at this time. However, the 21st-24th, 30th of September and 1st, 4th-5th of October are poor planting days. These days should be used for removing weeds, clearing land and ploughing fields.

 

Highlighted Possible Impacts on Agriculture:

During this third 15-day forecast period of (21st to 5th) September/October 2022, expect wetter conditions to occur as compared to the second 15-day (11th to 25th) September forecast period. There is a low probability (25%) chance for crop irrigation measures to take place due to gradually moistening soils during the forecast period. However, livestock should be provided with fresh, cool water during this forecast period to rehydrate, particularly during warmer and drier periods. During the second half of the forecast period, drier days when temperatures become higher are expected, there is a moderate probability (40%) chance of heat stress in young livestock, newly germinated and transplanted seedlings onto fields. There is also a moderate probability (60%) chance for fungi spread, root and/or fruit rot, insect pests and warm weather diseases to develop in crop beds. River levels will become high at times during the 21st-24th of September and will in general return to moderate to low levels during the rest of the forecast period.

Weather Assessment for the period September (11th-19th) 2022

Wet days occurred on the 11th-13th, 16th and 18th of September over Trinidad and Tobago. Low to moderate rainfall amounts that occurred across the islands assisted in replenishing soil moisture. Crop growth and development rates in general across agricultural lands and vegetation growth in pastures had decreased somewhat while river levels varied accordingly. The rainfall totals maps for the period, 11th to 19th of September for Trinidad and Tobago are located below as figure 1 and figure 2.

Figure 1. Rainfall map of Trinidad showing measured rainfall totals for varying districts during period 11th to 19th September 2022.

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during period 11th to 19th September 2022.

Temperatures:

Temperatures were cool to warm during the period 11th to 19th September, as the minimum nighttime temperature falling to 23.4 ⁰C and the maximum daytime temperature rising to 34.4 ⁰C, in Trinidad.

Similarly, Tobago temperatures were cool to warm during the period 11th to 19th September, with the minimum nighttime temperature falling to 24.8⁰C and the maximum daytime temperature rising to 32.3 ⁰C.