Agro-Meteorological Bulletin for the Second Dekad (11th - 20th) of January, 2021



ISSUED AT: 06:49 PM

Date: Sunday 10th of January 2021

Figure 1.

Figure 2.

Summary:

During the second dekad of January 2021, relatively dry days are expected on the 12th, 13th, 15th, 16th, and 18th; while relatively wet days are expected on the 11th, 14th, 17th, 19th and 20th. On relatively dry days expect intermittent cloudy patches with a low probability (25%) of showers and on relatively wet days expect intermittent cloudy periods with a moderate probability range (40% to 55%) of showers.


Agro-Meteorological Bulletin for the Second Dekad (11th - 20th) of January, 2021



ISSUED AT: 06:49 PM

Date: Sunday 10th of January 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 Assessment for the period (1st-9th) of January 2021.

During the period 1st to 9th of January, mostly relatively wet days occurred over Trinidad and Tobago, with the exception of the 1st, 6th, 7th and 8th; where few areas in Trinidad and Tobago had experience wet days. These wet days were due to cloudiness and rainfall associated with a low-level trough and localize effects. Rainfall totals’ maps for the period 1st to 9th of January are located below as figure 1 and figure 2.

 

Figure 1. Rainfall map of Trinidad showing measured rainfall totals for varying districts during period 1st to 9th of January 2021.

 

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during period 1st to 9th of January 2021.

 

The observed temperatures (maximum/minimum), average relative humidity (maximum/minimum) and long-term 10-day (10dys) averages for Piarco International Airport and ANR Robinson International Airport during first dekad of January 2021.

Location

Maximum Temperature

0C/ Long term 10 dys average 0C

Minimum Temperature

0C /Long term 10 dys average 0

Average maximum Relative humidity

(%)/ Long term 10 dys average (%) 

Average minimum Relative humidity

(%)/Long term 10 dys average (%) 

Trinidad (Piarco International airport)

31.7/30.8

(1981-2010)

19.0/21.8

(1981-2010)

87/93

(1990-2010)

65/68

(1990-2010)

 

Tobago (ANR Robinson International airport)

31.3/29.9

(1981-2010)

21.4/23.0

(1981-2010)

90/89

(1990-2010)

64/64

(1990-2010)

 

Table 1 shows the expected weather conditions during the Second Dekad (11th 20th) of January 2021, for Trinidad and Tobago.

Table 1.

Days:

Expected weather:

11th  

Intermittent cloudy patches with a moderate probability (55%) of showers.

12th   

Intermittent cloudy patches with a moderate probability (25%) of showers.

13th

Intermittent cloudy patches with a low probability (25%) of showers.

14th

Intermittent cloudy patches with a moderate probability (55%) of showers.

15th

Intermittent cloudy patches with a low probability (25%) of showers.

16th

Intermittent cloudy patches with a low probability (25%) of showers.

17th

Intermittent cloudy patches with a moderate probability (40%) of showers.

18th 

Intermittent cloudy patches with a moderate probability (25%) of showers.

19th

Intermittent cloudy patches with a moderate probability (55%) of showers.

20th

Intermittent cloudy patches with a moderate probability (55%) of showers.

 

Table 2 shows the expected temperatures, humidity and dust haze days during the second Dekad of January 2021 for Piarco, Trinidad.

Table 2.

Day

Maximum Temperature

0C

Minimum Temperature

0C

Average Relative humidity (%)

Dust Haze

Yes/No

11th  

31.7

22.0

78

Yes

12th

31.7

22.0

72

Yes

13th 

32.0

21.0

75

Yes

14th

31.5

22.5

75

Yes

15th

32.0

20.5

72

Yes

16th

32.0

21.0

72

Yes

17th

31.5

22.5

76

Yes

18th  

31.7

22.0

78

Yes

19th

31.7

22.0

78

Yes

20th

31.7

22.0

78

Yes

 

Table 3 shows the expected temperatures, humidity and dust haze days during the second Dekad of January 2021 for the ANR Robinson, Tobago.

Table 3

Day

Maximum Temperature

0C

Minimum Temperature

0C

Average Relative humidity (%)

Dust Haze

Yes/No

11th  

30.0

23.0

78

Yes

12th

31.0

23.0

75

Yes

13th 

31.0

22.0

72

Yes

14th

31.5

22.0

75

Yes

15th

31.0

22.0

72

Yes

16th

31.0

22.0

72

Yes

17th

30.7

23.0

76

Yes

18th  

30.7

23.0

78

Yes

19th

31.0

23.0

78

Yes

20th

31.0

23.0

78

Yes

 

Trinidad’s Mean Daily Rainfall Forecast for the second Dekad of January (11th -20th) 2021.

Northern & Northwestern areas:

Moderate chance (60%) of mean daily rainfall up to 2.1 mm.

North-Eastern and Eastern areas:

Moderate chance (68%) of mean daily rainfall up to 2.9 mm.

Central, West-Central and inland areas:

Moderate chance (60%) of mean daily rainfall up to 1.8 mm.

South-Eastern areas:

Moderate chance (68%) of mean daily rainfall up to 3.0 mm.

Southern areas:

Moderate chance (60%) of mean daily rainfall up to 2.1 mm.

South-Western areas:

Moderate chance (60%) of mean daily rainfall up to 1.6 mm.

 

Figure 3. Rainfall map of Trinidad showing possible rainfall totals for varying districts during the second dekad of January 2021 and percentage probability of occurrence.

 

Tobago’s Mean Daily Rainfall Forecast for the second Dekad of January (11th -20th) 2021.

Northeastern areas:

Moderate chance (60%) of mean daily rainfall up to 1.5 mm.

South-Western areas:

Moderate chance (68%) of mean daily rainfall up to 2.7 mm.

Figure 4. Rainfall map of Tobago showing possible rainfall totals for varying districts during the second dekad of January 2021 and percentage probability of occurrence.

 

Impacts on Agriculture:

During the second dekad of January 2021, relatively dry days are expected on the 12th, 13th, 15th, 16th, and 18th; while relatively wet days are expected on the 11th, 14th, 17th, 19th and 20th. There is a moderate (30%) probability that the anticipated rainfall will return sufficient soil moisture across Trinidad and Tobago. The expected rainfall events may result in rivers being at low levels. There is a moderate (30%) probability that some areas will become water-logged especially in low-lying areas during the dekad. Shrubs and grass-growth will continue at a medium pace. Additionally, with low average temperatures at this time and seldom-moist vegetation, there is a moderate (30%) probability for fungi spread, insect pests and warm weather diseases to develop.

Sun and Moon positions in the sky:

The sun is presently at a latitude of approximately 22 degrees South, and with this position, the day-length will be 11.4 hours. There is moderate probability (40%) of intense solar radiation during this second dekad of January, when the sky is generally cloud free. There is also moderate probability (30%) of heat stress on a variety of plant seedlings and young/sick/elderly animals from direct exposure to solar radiation, high temperatures with occasional calm winds. Additionally, the moon’s new moon phase will be on the 13th of January followed by first quarter phase on the 20th. As a result, there will be low to medium moon illumination over crop fields and livestock at night during the dekad.