Agro-Meteorological Bulletin for the Third Dekad (21st - 31st) of July, 2021



ISSUED AT: 08:38 AM

Date: Wednesday 21st of July 2021

Figure 1.

Figure 2.

Summary:

Summary of Expected Weather: Sufficient rainfall amounts are expected on seven of the fifteen days. A mixture of relative wet and wet days is expected for the 15-day period 21st to 4th of July/August 2021. Wet days with rainfall amounts 10.0 mm or greater are expected mainly on the 22nd, 26th, 27th, 28th, 31st, 2nd, and 4th, particularly in north-eastern, eastern, south-eastern, and southern parts of Trinidad and over south-western areas of Tobago. However, relatively wet days with rainfall amounts of 5.0 mm or less are expected mainly on the 21st, 23rd, 24th, 25th, 29th, 30th, 1st, and 3rd. Trinidad: Partly cloudy to cloudy spells are expected on days 22nd, 26th, 27th, 28th, 31st, 2nd, and 4th, which will likely bring light to occasionally moderate/heavy rainfall across farmlands in the north-eastern, eastern, south-eastern, southern, and southern-western areas of Trinidad. Daily rainfall totals are forecasted to be between 1.0 mm and 30.0 mm across different farmlands, with fifteen-day rainfall totals ranging between 60.0 mm and 100.0 mm. The heaviest and most long-lasting rains are expected over farmlands in the northeast areas of Sangre Grande, Fishing Pond, Plum Mitan, and Vega De Oropouche; eastern areas of Biche; southeast/south of Mayaro and Moruga and southwest areas of Point Fortin and La Brea . Otherwise, on days 21st, 23rd, 24th, 25th, 29th, 30th, 1st, and 3rd, expect partly cloudy conditions with few showers. Tobago: Tobago will experience drier conditions as a whole as compared to Trinidad. The island will experience wet days and relatively wet days over the 15-day period mostly in the south-western areas. Farmers should expect seven days of light to moderate/heavy rainfall amounts particularly on the 22nd, 26th, 27th, 28th, 31st, 2nd, and 4th. The daily rainfall totals are forecasted to be between 1.0 mm and 30.0 mm across different farmlands. The fifteen-day rainfall totals ranging between 40.0 mm and 60.0 mm across the island. However, on days 21st, 23rd, 24th, 25th, 29th, 30th, 1st, and 3rd, expect partly cloudy conditions with few showers. Temperatures & Winds: Maximum temperatures are expected to remain warm (29.0oC) to very warm (32.5oC) throughout most of the period but can reach (33.0oC) on the 24th, 25th, and 29th of July. However, temperatures are expected to have a real-feel or feels-like between 32.0oC to 44.0oC on most days. Moderate north-easterly to weak southeasterly winds of an average speed of 22 km/h are expected, with gusts ranging between 30 km/h to 40 km/h at times. Moderate rainfall totals, mostly moderate winds, warm to very warm days, and sensible feels-like temperatures will sustain average evapo-transpiration rates in crops ranging between 2.2 to 6.7 millimeters per day. Crop irrigation should be done when necessary, particularly on hot drier periods. Livestock should be provided with fresh cool water particularly on hot drier days to rehydrate. Moisture levels: Over the fifteen-day period across Trinidad and Tobago, moisture levels are expected to be low to moderate, with average daytime relative humidity values in the mid-50s to low-70s, in terms of percentage. While during possible rainy days of 22nd, 26th, 27th, 28th, 31st, 2nd, and 4th average daytime relative humidity values will be in the mid-70s to mid-80s, in terms of percentage.


Agro-Meteorological Bulletin for the Third Dekad (21st - 31st) of July, 2021



ISSUED AT: 08:38 AM

Date: Wednesday 21st of July 2021


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 – 4th) of July/August 2021

Date

Weather

Temperature

Heat

Real

Feel

Day Moisture

(Relative) (Humidity)

Wind

21st     

60% chance of showers

 

1.0 to 5.0  mm of   rainfall is possible

Few cloudy patches

with a shower or two

Warm      Max Temp 32.5oC

 

 

Feels like

37-40oC

 

 

55-62%

Moderate northeasterly

30 km/h

Gust

 40 km/h

22nd      

80% chance of light/moderate showers

 

1.0 to 30.0 mm  of rainfall with higher amounts on the east coast of Trinidad/Tobago

Cloudy with light to moderate/heavy showers

Warm           Max Temp 29.0oC

 

 

Feels like

32-38oC

 

 

66-85%

Weak easterly

16 km/h

Gust

 26 km/h

23rd     

60% chance of showers

 

1.0 to 5.0  mm of   rainfall is possible

Few cloudy patches

with a shower or two

Warm      Max Temp 32.5oC

 

 

Feels like

37-44oC

 

 

57-75%

Moderate northeasterly

20 km/h

Gust

 30 km/h

24th

40% chance of light/moderate  showers

 

0.0 to 2.0  mm of   rainfall is possible

Few cloudy patches

with a shower or two

Very Warm         Max Temp 33.0oC

 

Feels like

38-44oC

 

 

55-70%

Moderate easterly

20 km/h

Gust

 30 km/h

25th

40% chance of light/moderate  showers

 

0.0 to 2.0  mm of   rainfall is possible

Few cloudy patches

with a shower or two

Very Warm        Max Temp 33.0oC

 

Feels like

38-44oC

 

 

53-68%

Moderate easterly

20 km/h

Gust

 30 km/h

 

 

26th

80% chance of light/moderate showers

 

1.0 to 30.0 mm  of rainfall with higher amounts on the east coast of Trinidad/Tobago

Cloudy with light to moderate/heavy showers

Warm           Max Temp 30.0oC

 

 

Feels like

32-38oC

 

 

65-86%

Weak easterly

10 km/h

Gust

 20 km/h

27th

70% chance of light/moderate  showers

 

0.1 to 15.0  mm of   rainfall is possible

Mostly cloudy with light to moderate/heavy showers

Warm      Max Temp 30.0oC

 

Feels like

33-40oC

 

 

59-75%

Moderate easterly

20 km/h

Gust

 30 km/h

28th

80% chance of light/moderate showers

 

1.0 to 30.0 mm  of rainfall with higher amounts on the east coast of Trinidad/Tobago

Cloudy with light to moderate/heavy showers

Warm           Max Temp 29.0oC

 

 

Feels like

31-35oC

 

 

72-85%

Weak easterly

10 km/h

Gust

 20 km/h

29th

45% chance of light/moderate  showers

 

0.1 to 3.0  mm of   rainfall is possible

Few cloudy patches

with showers

Warm      Max Temp 33.0oC

 

Feels like

31-35oC

 

 

50-67%

Moderate northeasterly

20 km/h

Gust

 30 km/h

30th

65% chance of light/moderate  showers

 

0.1 to 5.0  mm of   rainfall is possible

Few cloudy patches

with showers

Warm      Max Temp 32.0oC

 

Feels like

37-44oC

 

 

60-70%

Moderate northeasterly

20 km/h

Gust

 30 km/h

31st  

80% chance of light/moderate showers

 

1.0 to 30.0 mm  of rainfall with higher amounts on the east coast of Trinidad/Tobago

Cloudy with light to moderate/heavy showers

Warm           Max Temp 30.0oC

 

 

Feels like

32-35oC

 

 

70-81%

Weak easterly

10 km/h

Gust

 20 km/h

1st   

55% chance of light/moderate  showers

 

0.1 to 3.0  mm of   rainfall is possible

Few cloudy patches

with showers

Warm      Max Temp 32.0oC

 

Feels like

38-42oC

 

 

60-70%

Moderate northeasterly

20 km/h

Gust

 30 km/h

2nd

65% chance of  light/moderate showers

 

 

1.0 to 10.0 mm of   rainfall is possible

Partly cloudy to cloudy with showers

Warm           

Max Temp 32.0oC

 

 

Feels like

 

36-42oC

 

 

 

   60-80%

Moderate easterly

20 km/h

Gust

 30 km/h

3rd

55% chance of light/moderate  showers

 

0.1 to 3.0  mm of   rainfall is possible

Few cloudy patches

with showers

Warm      Max Temp 32.0oC

 

Feels like

31-42oC

 

 

60-70%

Moderate northeasterly

20 km/h

Gust

 30 km/h

4th 

65% chance of  light/moderate showers

 

 

1.0 to 10.0 mm of   rainfall is possible

Partly cloudy to cloudy with showers

Warm           

Max Temp 32.0oC

 

 

Feels like

 

36-42oC

 

 

 

   60-80%

Moderate easterly

20 km/h

Gust

 30 km/h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Trinidad Rainfall Forecast for the 15-Day period of July/August (21st –4th) 2021

 

Figure 1.  Rainfall map of Trinidad showing expected mean rainfall totals for districts across Trinidad during the 15-day period (21st-4th) July/August 2021 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 10.0 mm.

Southern areas

Moderate chance (68%) of mean daily rainfall up to 9.8 mm.

South-Western areas 

Moderate chance (68%) of mean daily rainfall up to 9.7 mm.

Central, West-Central, and inland areas

Moderate chance (65%) of mean daily rainfall up to 6.0 mm.

Northern, North-Western areas     

Moderate chance (65%) of mean daily rainfall up to 6.0 mm.

Tobago Rainfall Forecast for the 15-Day period of July/August (21st – 4th) 2021

Figure 2.    Rainfall map of Tobago showing expected mean rainfall totals for districts across Trinidad during the 15-day period (21st-4th) July/August 2021 and percentage probability of occurrence.

North-Eastern areas

Moderate chance (65%) of mean daily rainfall up to 4.0 mm.

South-Western areas

Moderate chance (68%) of mean daily rainfall up to 5.1 mm.

Sun and Moon Positions in the Sky July/August (21st to 4th) 2021

The sun is presently at the latitude of 22.0 degrees North latitude and with this position, the day-length or number of sunlight hours in Trinidad and Tobago from July 21st will be 12 hours 40 minutes, reducing steadily to 12 hours and 33 minutes by the 4th August.

 According to the moon phases, days 21st and 22nd are good days for planting above-ground crops, while the days 25th, 26th, 27th, 30th, 31st of July also 1st and 4th of August are good days for planting below-ground crops. However, the 28th and 29th of July are barren days, and the 23rd (Full Moon phase), 24th of July, also 2nd and 3rd of August are poor planting days. These days can be used for removing weeds, clearing land, and ploughing fields.

Highlighted Possible Impacts on Agriculture:

Farmlands in Trinidad and Tobago had received low to moderate amounts of rainfall during the last dekad (11th-19th) of July. A continuation of this weather trend is expected for this third 15-day period of July/August. Expect mostly relatively wet days, with few wet days to occur during the period. The few sunny spells, light to moderate winds, and low to moderate rainfall amounts in this third fifteen-day period of July/August, will sustain average evaporation and average evapotranspiration rates overall.

There is a moderate probability (68%) chance of heat stress in young livestock, newly germinated and transplanted seedlings onto fields. Warm to very warm days with high feel like temperatures and frequent periods of moist crop vegetation, will increase the chances for fungi spread, fruit or root rot, insect pests, and warm weather diseases to develop in crop beds.

During this 15-day period, river levels and soil moisture will become moderate to low, adding to the drying out of some waterlogged soils, fields, and pastures. However, there are a few wet days expected for this period. Therefore, farmers should remain prepared with necessary flood alleviating actions such as portable water pumps, sandbags, and elevated structures on the ground to store animals, seedlings, machinery, and other equipment.

Weather Assessment for the period July (11th -19th) 2021.

During the period (11th to 19th) of July 2021, low to moderate amounts of rain fell in many areas of Trinidad and Tobago. In Trinidad and Tobago on days 11th and 16th were the days that had moderate rainfall amounts. These rainfall days may have sustain soil moisture and moderate river levels, which have assisted rain-fed agricultural lands and pastures. On others days, mostly relatively wet conditions predominated over both islands. The rainfall totals maps for the period 11th to 19th of July 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 of July 2021.

 

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during the period 11th to 19th of July 2021.

Temperatures:

Temperatures remained warm during the period as maximum daytime temperatures ranged between 28.3 ⁰ C and 32.0 ⁰ C, in Trinidad.

 In Tobago, temperatures were warm, with maximum daytime temperatures ranging between 28.7 ⁰ C and 32.7 ⁰ C.