Quarterly Marine Meteorologicalbulletin

Quarterly Marine Meteorologicalbulletin

NIGERIAN METEOROLOGICAL AGENCY (NIMET),

QUARTERLY MARINE METEOROLOGICALBULLETIN

VOL.1/1/16FIRST QUARTER 2016


TABLE OFCONTENTS

ContentsPage

Preface2

1.0Synoptic Review3

1.1The Inter-Tropical Discontinuity (ITD)3

1.2January3

1.3February4

1.4March5

2.0Seas Surface Temperature Analysis5

3.0Sample of Daily Marine Weather Forecast15

4.0Weather Outlook for the next Quarter19

Preface

The Nigerian Meteorological Agency (NiMet) has produced the first edition of the 2016 Marine Meteorological Quarterly Bulletin for January – March 2016 period. The bulletin details marine meteorological and oceanographic information such as the sea-state and forecasts for marine users both at sea and along the coast. The information also constitutes early warnings against weather-related hazards such as severe storm surges, coastal flooding and erosion for safety of lives and property. They also serve as useful guides for enhanced productivity in the maritime industry. The marine weather stations from which the bulletin source its data are located at East mole, Nigerian Institute of Oceanography and Marine Research (NIOMR) Lagos, Eket in Akwa Ibom State, Koko in Delta State, Aiyetoro in Ondo State, and Calabar marine station in Cross- River State.

The Nigerian coastline lies between Latitude4° 10’ to 6° 2’ N and Longitude 2° 45’ to 8° 35’ E spanning about 853km of low-lying coast. The coast is bordered by a narrow continental shelf of the Gulf of Guinea, shelf widths range from 15km in the West to about 67km in the Niger Delta and about 87km off the Cross River estuary in the East. The Nigerian coastal zone comprises of Lagos, Ondo, Delta, Rivers, Bayelsa, Akwa Ibom and Cross River States and parts of Edo State where an estimated 25 percent of the population of the country live. There are high economic activities with Ports, harbor and major maritime and oil and gasindustries in the coastal area.

1.0Synoptic Review

1.1The Inter-Tropical Discontinuity (ITD)

Figure 5 shows the variation of the Inter-Tropical Discontinuity (ITD) during the first quarter of 2016. Notice the sharp increase in latitudinal positions of the ITD from February, moving from an average position of6.6oN to nearly 13.0oN in March. The mean ITD position was observed to be lower than normal in the 1st dekade of January, this resulted to the extreme dryness experienced in most cities during this period. The trend continued in February however, a significant Northward surge was observed in all the three dekades in March. This may be connected to the episodes of rainfall events that were recorded in most stations in Nigeria, especially stations along the coast in March. The monthly details of the synoptic situation during the first quarter of the year are given below.

1.2January

In January, the Inter-Tropical Discontinuity (ITD) positionfluctuatedbetween latitudes5.3°N and 7.9°N, leaving an average latitudinal position was 6.6°N. The winds were predominantly southwesterly, occasionally backing southeasterly with speed ranging from 5 - 12kts, occasionally 15kts. Mean daily maximum and minimum temperaturesranged between 30.8°C - 33.9°Cand 12.50C- 28.40C respectively, while the average Sea Surface Temperature (SST)was between28.8°C and 28.90C.The coastal Mean Sea Level Pressure (MSLP) valuesfluctuated between 1010 - 1013hPa, filling up to 1014 – 1016hPa occasionallywhile the center value of St. Helena high pressure was between1019hPa and1036hPa with an averagevalue of 1025hPa throughout the month.

Fig 5a: Time series analysis of ITD position in the 1st quarter of 2016

Parts of the coastal area experiencedearly morning mist/fog as well as hazy conditionsduring the month with occasional thundery activities.The sea state ranged from slight to moderate. Rainfall amount recorded in the various stations were 1.0mm and 25.6mm atEket and East Mole respectively.There were no records of disruption of activities due to adverse weather at the ports and coastal areas.In January, the minimum (night time temperature) was coldest around Lagos and Calabar coast while the maximum (day-time temperature) was warmest around Koko and Aiyetoro area.

1.3February

There was a northward incursion of theInter Tropical Discontinuity (ITD), reaching a maximum position of 9.10N with ameanapproximateposition of 7.4°N during the month.South Westerly winds dominated the coast with average speedof between5-10kts, occasionally increasing to 17kts.The coastal mean sea level pressure (MSLP) fluctuated between 1010hPa and 1015hPa with an average value of 1013hPa, while the St. Helena high pressure centre had values ranging from1020hPa to 1024hPawith peak 1028hPa. Calabararea was warmer than the southwest (Lagos) coast as indicated bymaximum temperature values of 35.7°C and 33.5°C respectively.

Theobserved Sea surface temperature was higher compared to January at 29.40C and 29.0Cin Eket and East molerespectively. The rainfall for the month improved slightly from the situation in January as this month coincides with the onset of rainy season along the coast.Eket recorded 16.2mm while Lagos had13.7mm.The sea state remained slight to moderate. Hazy conditions were experienced around the coast reducing visibility during the month.Night-time temperature was at its lowest over Aiyetoro(12.60C) while day-time temperature was relatively uniform over the entire Nigerian coast in February, 2016.



Fig 2a– 2d: Map showing mean maximum temperatures over the coast during the first quarter 2016.

1.4March

The Inter Tropical Discontinuity (ITD) linecontinued its northward movementfluctuating between Lat. 8.9°N, and12.8°Nwith an approximateaverage position of 10.9°N. The wind flow was South Westerly, with speed ranging 5-15knots. The mean coastal maximum temperature at Lagos, Calabar, and Eket areas were30.9°C, 31.6°C and 30.4°C respectively. The Sea Surface Temperature (SST) was relatively higher than it was in February over Eket and East Mole. Average SST at Eket and East mole was29.9°Cfor the two Stations. The mean surface pressure was between 1008 - 1012hPa, while the centralvalues of the St. Helena high pressure system intensified from1021hPa to 1033hPa bringing in more moisture into the country leading to increased rainfall amounts recorded for most parts of the coast during the period.Lagos, Eket and Calabar observed rainfall were 162.2mm, 383.2mm and 118.6mm respectively whileAiyetoro and Koko had 175.6mm and 166.6mm respectively.The sea state was slight to moderate.The highest maximum temperature was observed at Kokoin Delta State with a valueof 35.60C while the lowest minimum occurred at Calabar marine (15.50C) in March, 2016.



Fig 3a – 3d: Map showing mean minimum temperatures over the coast during the first quarter 2016.

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2.0The Sea Surface Temperature (SST) Analysis

Figures 4a and 4b are the Sea Surface Temperatures (SST) variation in the first quarter of the yearover Victoria Island, Lagos and Eket. They are showing increasing trend during the period.

Fig 4a: Variation of SST over Victoria Island Fig 4b: Variation of SST over Eket

Sample of Daily Marine Weather Forecast

NIGERIAN METEOROLOGICAL AGENCY (NIMET),

NATIONAL WEATHER FORECASTING AND CLIMATE RESEARCH CENTRE,

NNAMDI AZIKWE INTERNATIONAL AIRPORT, P.M.B. 615, GARKI, ABUJA, NIGERIA

FORECAST FOR INSHORE WATERS OF NIGERIA up to 20km offshore(60 13'N, 2054'E to 40 32'N, 80 23'E)
Issued at 1500 UTC on Wed. 23rd Mar, 2016, and valid during

1800 UTC Wed. 23rd to 1800 UTC Thur. 24th Mar, 2016.

Period of Forecast: 1800 UTC Wed. 23th to 1800 UTC Thur. 24th Mar, 2016.

WARNING: NIL

General Situation: The surface wind pattern, 10m and 50m are expected to be south westerly and dew point temperature will have values ranging from 24-250C indicated that coastal areas will be humid. The surface pressure system is expected to be under the influence of a low over the forecast area with values 1008 - 1013hPa at about 1800 UTC. It is expected to remain quasi stationary till the end of forecast period. Winds are expected to be south westerly with thunderstorm in some areas. Light to moderate occasionally fresh breeze are expected.

Calabar, Eket and Port Harcourt coastal waters
24 Hour forecast
Wind: South westerly backing southerly, 5 – 10kts occasionally 18kts.
Sea state:Large wavelets; crests begin to break; foam of glassy appearance; perhaps scattered horses to small waves, becoming longer; fairly frequent white horse(Slight to moderate)

Tide: Cal –High: 2.9m (0600 UTC), low: 0.6m (1220 UTC)
PHC–High: 2.3m (1815 & 0625 UTC), low: 0.3m (2345 & 1150 UTC)
Weather: Rain with chances of thunderstorm, Sig. wave height: 0.9 – 1.2m
Visibility: Moderate (4 -10km), poor in thunderstorm (2.0 – 4.0km).

Outlook for the following 24hrs:
Wind:South westerly, 5 – 10kts occasionally 16kts.
Sea State: Large wavelets; crests begin to break; foam of glassy appearance; perhaps scattered horses to small waves, becoming longer; fairly frequent white horses(Slight to moderate)

Weather: Fair, chances of rain/thunderstorm later.

Visibility: Moderate (4 - 10km).

Warri, Koko and Aiyetoro coastal waters
24 hr forecast
Wind: South westerly,5 - 10kts occasionally 15kts
Sea State:Small waves, becoming longer; fairly frequent white horses(Moderate)

Tide: Warri –High: 1.9m (2020 UTC), low: 0.5m (1405 UTC)
Weather: Fair, chances of rain/thunderstorm later.

Sig. wave height: 1.2 – 1.3m
Visibility: Moderate (4 -10km).

Outlook for the following 24hrs
Wind: South westerly, 5 -10kts occasionally 17kts.
Sea State: Small waves, becoming longer; fairly frequent white horses(Moderate)

Weather: Fair, chances of isolated rain with thunderstorm later.

Visibility: Moderate(4 – 10km).

Lagos Coastal Waters
24hr forecast:
Wind: South westerly, 5 – 10kts occasionally 18kts.
Sea State: Small waves, becoming longer; fairly frequent white horses(Moderate)

Tide: High: 1.0m (1655 UTC), low: -0.1m (1035 UTC)
Weather: Fair, isolated rain with thunderstorm later.

Sig. wave height: 1.2 – 1.6m
Visibility: Moderate (4 -10km).

Outlook for the following 24hrs
Wind: Southwesterly, 5- 10kts occasionally 15kts.
Sea State:Small waves, becoming longer; fairly frequent white horses(Moderate)

Weather: Fair, isolated rain with chances of thunderstorm later.

Visibility: Moderate (4 -10km).

End.

SHIPPING FORECAST TO 650KM OFFSHORE (60 13'N, 20 54'E - 40 32'N, 8023'E toequator)ISSUED BY NIGERIAN METEOROLOGICAL AGENCY (NIMET), at 1500 UTC on Wed. 23rd Mar, 2016VALID FOR: 1800 UTC on Wed. 23rdto 1800 UTC Thur. 24th Mar, 2016.

WARNING: NIL

GENERAL SYNOPSIS: The centre value of St Helena's high pressure system is expected to fluctuate between 1025 - 1030hPa from 1800 UTC to the end of forecast period. There is an indication of high moisture content in the atmosphere during the forecast period. A low pressure system is expected with values 1009 - 1014hPa at about 1800 UTC, it’s expected to remain same till the end of forecast period. Lightto moderate occasionally fresh breeze is expected with thunderstorm.

THE AREA FORECASTS FOR THE NEXT 24 HOURS

WIND: South westerly 05– 10kts occasionally 20kts

SEA STATE:Large wavelets; crests begin to break; foam of glassy appearance; perhaps scattered horses to small waves, becoming longer; fairly frequent white horses(Slight to moderate)

WEATHER: Rain then thunderstorm.

Sig. wave height: 0.9 – 1.5m

Visibility: Moderate (4 - 10km)

END.

: April, 2016

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