Agro-Meteorological Bulletin for the Third Dekad (21st - 31st) of January, 2020



ISSUED AT: 04:08 PM

Date: Thursday 23rd of January 2020

Figure 1.

Figure 2.

Summary:

During the third dekad of January, relative wet days are expected on the 21st, 24th, 25th, 30th, and 31st , whereas relatively dry days on the 22nd, 23rd, 26th, 27th, 28th and 29th. On relatively wet days, expect partly cloudy skies with a moderate probability (60%) of few brisk showers. While during relative dry days expect few cloudy patches with a low probability (20%) of a brief shower or two.


Agro-Meteorological Bulletin for the Third Dekad (21st - 31st) of January, 2020



ISSUED AT: 04:08 PM

Date: Thursday 23rd of January 2020


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 Second Dekad (11th – 20th) of January 2020.

More relatively wet days occurred during the second dekad of January in Trinidad and Tobago. Rainfall total maps for the period 11th  to 20th 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 11th  to 20th  of January 2020.

 

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during period 11th   to 20th  of January 2020.

 

 

 

The observed Temperatures (maximum/minimum), Average Relative humidity (maximum/minimum) and Long term 10 days (10dys) averages for locations: Piarco International airport and ANR Robinson International airport.

 

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)

31.8/30.9

(1981-2010)

21.8/21.4

(1981-2010)

90/96

(1990-2010)

75/56

(1990-2010)

 

Tobago (ANR Robinson International airport)

31.1/29.9

(1981-2010)

22.4/22.7

(1981-2000)

82/87

(1990-2010)

70/62

(1990-2010)

 

The Expected Weather conditions during the Third Dekad (21st – 31st) of January 2020, for Trinidad and Tobago, as seen in table 1.

Table 1.

Days:

Expected weather:

21st  

Partly cloudy with a moderate probability (60%) of few brisk showers.

22nd    

Few cloudy patches with a low probability (20%) of a brief shower or two.

23rd

Few cloudy patches with a low probability (20%) of a brief shower or two.

24th

Partly cloudy with a moderate probability (60%) of few brisk showers

25th

Partly cloudy with a moderate probability (60%) of few brisk showers

26th

Few cloudy patches with a low probability (20%) of a brief shower or two.

27th

Few cloudy patches with a low probability (20%) of a brief shower or two.

28th 

Few cloudy patches with a low probability (20%) of a brief shower or two.

29th

Few cloudy patches with a low probability (20%) of a brief shower or two.

30th

Partly cloudy with a moderate probability (60%) of few brisk showers

31st

Partly cloudy with a moderate probability (60%) of few brisk showers

 

The expected Temperatures, Humidity and Dust haze days during the Third dekad of January for Piarco, Trinidad as seen in table 2.

Table 2.

Day

Maximum Temperature

0C

Minimum Temperature

0C

Average Relative humidity (%)

Dust Haze

Yes/No

21st  

31.2

21.8

84

Yes

22nd

31.8

21.8

80

Yes

23rd

31.8

21.8

80

Yes

24th

31.2

22.2

83

No

25th

31.2

22.2

83

No

26th

31.6

22.2

82

Yes

27th

31.8

21.8

79

Yes

28th  

31.8

21.8

77

Yes

29th

31.8

21.8

77

Yes

30th

31.2

22.0

84

No

31st

31.3

22.2

85

No

 

The expected Temperatures, Humidity and Dust haze days during the Third dekad of January for ANR Robinson, Tobago as seen in table 3.

Table 3

Day

Maximum Temperature

0C

Minimum Temperature

0C

Average Relative humidity (%)

Dust Haze

Yes/No

21st

31.1

22.4

77

Yes

22nd

31.4

22.4

76

Yes

23rd

31.4

23.3

76

Yes

24th

31.0

23.3

78

No

25th

31.0

23.0

79

No

26th

31.2

22.4

76

Yes

27th

31.4

22.4

76

Yes

28th

31.4

22.4

76

Yes

29th

31.4

22.4

76

Yes

30th

31.0

22.4

79

No

31st

31.0

22.4

79

No

 

Tobago’s Mean Daily Rainfall Forecast for the Third Dekad of January (21st–31st) 2020.

Northern & Northwestern areas:

Moderate chance (68%) of mean daily rainfall up to 6.3 mm.

North-Eastern and Eastern areas:

Moderate chance (68%) of mean daily rainfall up to 6.6 mm.

Central, West-Central and inland areas:

Moderate chance (60%) of mean daily rainfall up to 3.0 mm.

South-Eastern areas:

Moderate chance (68%) of mean daily rainfall up to 6.0 mm.

Southern areas:

Moderate chance (64%) of mean daily rainfall up to 4.1 mm.

South-Western areas:

Moderate chance (60%) of mean daily rainfall up to 3.0 mm.

 

 

Figure 3. Rainfall map of Trinidad showing possible rainfall totals for varying districts during Third dekad of January 2020 and percentage probability of occurrence.

 

Tobago’s Mean Daily Rainfall Forecast for the Third Dekad of January (21st–31st) 2020.

Northeastern areas:

Moderate chance (68%) of mean daily rainfall up to 7.0 mm.

South-Western areas:

Moderate chance (68%) of mean daily rainfall up to 7.0 mm.

Figure 4. Rainfall map of Tobago showing possible rainfall totals for varying districts during Third dekad of January 2020 and percentage probability of occurrence.

 

 

Impacts on Agriculture:

During the third dekad of January 2020, relative wet days are expected on the 21st, 24th, 25th, 30th, and 31st , whereas relatively dry days on the 22nd, 23rd, 26th, 27th, 28th and 29th.  The transitioning process from the rainy season to the dry season is continuing at a slow pace, soil moisture will continue to remain steady with mix conditions across Trinidad and Tobago, resulting in steady vegetative growth. Rivers will replenish their waters from mostly ground water flow and surface runoff, while shrubs and grass growth will continue at a reduced but steady pace. Additionally, with the mean temperatures and relative humidity being lowest, as expected at this time of the year, there is a low (20%) probability of some agricultural insects, pests, fungi and diseases get a foot in and possibly develop.

Sun and Moon positions in the sky:

 The sun is presently at latitude of approximately 19.75 degrees south latitude, and with this position, the day length for this dekad will be 11.5 hours. A low probability (20%) of intense solar radiation occurring during the third dekad of January, 2020 when the sky is generally cloud free. There is low probability (10%) of heat stress on variety plant seedlings and young/sick/elderly animals from direct exposure to direct solar radiation and warm temperatures. Additionally, the moon’s new moon phase will be on the 24th of January as a result, there will be medium to low moon illumination over crop fields and livestock at night during the dekad.