Published by the Nigerian Meteorological Agency (Nimet)

MARINE METEOROLOGICAL

QUARTERLY BULLETIN

VOL X NO III. July - Sept., 2012

PUBLISHED BY THE NIGERIAN METEOROLOGICAL AGENCY (NIMET)

P. M. B 1215, Oshodi, Lagos.

E-mail:

Oct., 2012

CONTENTS

Pages

Contents ………………………………………………………………………………………………………… 1

General Terms ……………………………………………………………………………………………….. 2

Introduction …………………………………………………………………………………………………. 3

Quarterly Coastal Weather Review ………………………………………………………………. 6

Meteorological Data for Lagos and Eket Area ………………………………………………. 9

Day- time Sea Surface Temperature (SST) over Eket in Akwa Ibom, State

for Jul - Sept. 2012 ………………………………………………….……………………………………… 10

Day- time Sea Surface Temperature (SST) over Koko, Delta State

for Jul - Sept. 2012 ………………………………………………………………………………………….. 11

Day- time Sea Surface Temperature (SST) over Calabar inCross River, State

for Jul - Sept. 2012 …………………………………………………………………………………………… 12

Sample of Daily Marine Weather Forecast ……………………………………………………… 13

Weather Outlook for the next Quarter……………………………………………………………… 15

PUBLISHED BY THE NIGERIAN METEOROLOGICAL AGENCY

P. M. B 1215, Oshodi, Lagos.

Tel: 234-8O23213456,

E-mail:

GENERAL TERMS

Inter-tropical discontinuity (ITD) - Transitional zone between dry north easterly wind and

moisture laden south westerly winds.

Ridge - An elongated zone of relatively high atmospheric pressure.

Swell - Waves at point of observation which have travelled some

distance from the area where they were generated at sea.

Sea Waves - Sea waves are also known as wind waves. They are waves

raised locally by wind blowing over a stretch of water.

Tide - The regular rise and fall in the surface level of the oceans,

caused by gravitational attraction of the moon and sun.

HSM - Wave Height

Sea Surface Temperature (SST) - The temperature of the sea surface representing the

condition the surface mixed layer underlying the ocean skin.

FORECAST

Slight - use for describing sea state: indicating wave height between 0.5 – 1.25 metres

Moderate - use for describing sea state: indicating wave height between 1.25 – 2.50 metres

Rough - use for describing sea state: indicating wave height between 2.50 – 4.0 metres

Fair - use in describing weather condition: no precipitation or fog is expected

Visibility: - Good is between10 – 20km

Moderate is between 4000m – 10km

Poor is between 1000 – 4000m

Very poor is below 1000m

Wind: Light air -1-3knots

Light breeze -4-6knots

Gentle breeze -7-10knots

Moderate breeze-11-16knots

Fresh breeze -17-21knots

Strong breeze-22-27knots

INTRODUCTION

The Nigerian coastal zone lies within Lat 4° 10’ to 6° 2’ N and Longitudes 2° 45’ to 8° 35’ E spanning about 850km of low-lying coastline. 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 with about 25% of the estimated population of the country. There are high economic activities with Ports, harbor and major industries in the coastal area.

Nigerian Meteorological Agency is vested with the responsibility of monitoring weather and climate as its statutory functions. The Agency is working out modalities of having collaboration with other likeminded Organizations and Institutions, which will eventually enhance better development in Marine Meteorology and Oceanography.

The task of analyzing the observed weather pattern and changes with a view of informing the general public, marine users including ships and coastal dwellers is therefore given priority attention by the Agency. At present the Division is made up of five functioning operational coastal stations, which are: East mole, Nigerian Institute of Oceanography and Marine Research (NIOMR) in Lagos, Eket in Akwa Ibom State, Koko in Delta state and Calabar marine station. Six other stations are being established while a buoy with marine sensors will soon be installed at the Lagos area of the Atlantic Ocean.

The Division issues daily marine weather forecasts for shipping and fishing industries, oil companies and other coastal users.

MISSION

The mission of Marine Meteorological Division is to make available to marine users at sea or on the coast, marine meteorological and related geophysical information which they require to the extent technically possible and to generate revenue for the Agency.

PRODUCTS AND SERVICES

Observation, collation and analyses of all Marine Meteorological parameters.
Dissemination of marine information to marine users.
Issuing of daily Marine weather forecasts (Inshore & Shipping)
Production of quarterly Marine Meteorological bulletin.
Provision of special Marine services on request.
Carrying out research in Marine Meteorology and Oceanography.
Provision of consultancy services in the area of Marine Meteorology and Oceanography.
Capacity building through training of students on attachment.
Teaching of Marine Meteorology in WMO Regional Meteorological Training Institute, Oshodi.

Developing and maintaining necessary contacts with other institutions and Establishments in and outside Nigeria in marine related activities through appropriate Authority in the Agency.
Participation in conferences on Oceanography and Marine Meteorological matters.
Generation of revenue from Marine services and products.

POTENTIAL USERS

Shipping industry.
Oil industry
Fishing Industry
Insurance companies
Researchers from higher Institutions, Government Institutions and interested bodies/individuals.
Media and press.
Engineering and construction companies in Coastal areas.
Coastal Dwellers, Tourist etc.
The General public.
Government Corporations.

QUARTERLY COASTAL WEATHER REVIEW

July

The ITD continued its northward movement from its average position in the previous month. It fluctuatedbetween latitudes18.8°N and 19.0°N, with an average latitudinal position of 18.9°N. . On the 850hPa chart, the wind flow was mainly Southwesterly with an average speed of 5 - 15kts occasionally 25kts over the coast. The mean coastal maximum temperature in Lagos and Eket areas were31.8°C and 26.8°C respectively. The average Sea Surface Temperature for Koko was 28.3°C whileit was 26.3°C in Eket and Calabar. Theaverage value of the coastal Mean Sea Level Pressure (MSLP) was1011hPa while the St. Helena high pressure centre was between 1024hPa and 1032hPa with an average value of 1028hPa.

Adverse weather and flooding wrecked parts of the coastal area between the 3rd day and 26thday of the month. Places affectedincludeLagos, Benin, and parts of South-South area. The winds were southwesterly with speed ranging from 5 – 15kts, occasionally 25kts. The sea state was slight to moderate, occasionally rough while the sea surface temperature (SST) was warmer than the previous month. Rainfall amount recorded in Lagos and Calabar area were 250.2mm and 637.1mm respectively while Port Harcourt had 326mm and Owerri 430.2mm. There were records of disruption of activities due to adverse weather as published in a number of National dailies. The Punch Newspaper reported on 3rd, 13th, 16thand 23rd July,that flood sacked commercial hubs of Lagos, Benin and some other coastal areas after the down pour.

Traders, farmers and residents lamented atIsheri and Ikeja of Lagos while Port and Harbour operations and other coastal activities were disrupted.

August

The ITD fluctuated between latitudes 19.2°N and 20.0°N with an average position of approximately Lat 19.7°N.This broughtthe entire country under the influence of moisture lading Southwesterlies which agrees with climatological finding that the ITD reaches its northernmost position in August.

The coastal mean sea level pressure (MSLP) fluctuated between 1010hPa and 1014hPa with an average value of 1012hPa while the St. Helena’s high pressure centre had values ranging from1024hPa to 1028hPa.

Lagos area was warmer than the South - South with maximum temperature of 30.8°C and 26.9°C respectively.

As would be expected, thesea experienced reduction in temperature during the month of August which is usually the coldest in the year. The average Sea Surface Temperature overCalabar, Eket and Koko were25.9°C, 26.2°C and 29.3°C respectively. The winds were south westerlies with moderate speed on the average.

The amount of rainfall recorded this month exceeded that of July in most parts of the coastal area,Lagos however was less. Victoria Island had10.4mm, Calabar 861.3mm, Port Harcourt 304.7mm.

The sea state was moderate and occasionally rough. There was devastating storm surges on 17th and 18th of the month resulting in loss of lives and property in Kuramo beach axis in Lagos. Fall in barometric pressure at the coast and favourable wind flow acting on the waves from source region was responsible for the flood. There were disruption of coastal engineering works, transportation, commercial and some other activities over the coast as a result of flooding.

September

The ITD commenced its southward movement fluctuating between Lat. 18.3°N and17.8°Nwith an approximately average position of 18.1°N. On the 850hPa chart, the flow was Southwesterly, with an average speed of 15knots.

The mean coastal maximum temperature at Calabar and Eket areas were29.6°C and 27.5°C respectively. The Sea Surface Temperature (SST) was higher than it was in August. Average SST at Eket, Koko and Calabar were 26.3°C, 29.6°C and 26.3°C respectively. The mean surface pressure was 1013hPa, while the values of centre of the St. Helena’s high pressure ranged from1028hPa to 1036hPa.

Rainstorms continued in the coastal area as it was experienced in some parts during the month of August.

A number of activities were disrupted assomepartsof the area experienced flood, motorists in Lagos were worried because of Lagos; Lekki- Epe road erosion.

The winds were southwesterly with speed ranging from 5 – 20kts occasionally 27kts. The sea state was slight to moderate occasionally rough.

Port and Harbour operations and other coastal activities were also disrupted as a result of adverse weather. The adverse weather sent caution to the Government and people of the Coastal Area. People living in flood prone areas became apprehensive whenever the weather was cloudy, they were advised to relocate to higher ground.

Meteorological Data for Lagos and Eket Area

LAGOS AREA

MEAN
ITD position
(°N) / Wind Direction / Mean
Wind Speed (Kts) / Mean Min.
Temp. (°C) / Mean Max. Temp.
(°C) / Rainfall Amount (mm) / Surf.Pres. st. Helena hPa / Sea Surf. Temp. (°C)
July / 18.9 / South westerly / 10kts / 26.1 / 31.8 / 250.2 / 1024 / xxx
August / 19.9 / South westerly / 18kts / 25.5 / 31.2 / 10.4 / 1036 / xxx
September / 18.0 / South westerly / 22kts / 23.4 / 31.5 / 184.5 / 1028 / xxx

EKET IN SOUTH - SOUTH AREA

MEAN
ITD position
(°N) / Wind Direction / Mean
Wind Speed (Kts) / Mean Min.
Temp. (°C) / Mean Max. Temp.
(°C) / Rainfall Amount (mm) / Surf.Pres. st. Helena hPa / Sea Surf. Temp. (°C)
July / 18.9 / South westerly / 20kts / 23.4 / 27.2 / 369.6 / 1024 / 26.3
August / 19.9 / South westerly / 15kts / 23.4 / 28.0 / 339.6 / 1036 / 25.9
September / 18.0 / South westerly / 15kts / 23.5 / 29.5 / 289.3 / 1028 / 26.2

DAY – TIME SEA SURFACE TEMPERATURE (SST) OVER EKET,

AKWA IBOM STATE FOR July -Sept., 2012.

(DAILY AVERAGES IN °C)

DAY / July. / Aug. / Sept.
1 / 27.0 / 22.8 / 25.5
2 / 26.0 / 25.4 / 25.7
3 / 26.6 / 25.4 / 26.0
4 / 26.9 / 24.8 / 27.0
5 / 25.5 / 25.4 / 26.6
6 / 26.2 / 26.5 / 25.3
7 / 25.8 / 26.5 / 26.2
8 / 25.9 / 26.8 / 24.6
9 / 26.5 / 26.9 / 25.0
10 / 26.8 / 26.7 / 26.5
11 / 26.3 / 26.9 / 27.4
12 / 27.1 / 26.9 / 25.3
13 / 28.0 / 26.9 / 26.3
14 / 26.7 / 27.4 / 25.9
15 / 27.7 / 27.8 / 24.9
16 / 28.3 / 27.0 / 27.4
17 / 27.8 / 27.3 / 26.9
18 / 26.3 / 27.2 / 26.9
19 / 25.4 / 27.6 / 26.7
20 / 26.0 / 25.8 / 26.8
21 / 26.7 / 26.7 / 26.7
22 / 24.5 / 26.5 / 25.9
23 / 25.5 / 25.3 / 26.8
24 / 26.5 / 25.1 / 27.1
25 / 26.2 / 25.5 / 24.6
26 / 26.0 / 27.2 / 27.2
27 / 26.9 / 26.9 / 27.4
28 / 26.7 / 25.7 / 27.3
29 / 25.8 / 25.8 / 26.3
30 / 24.6 / 25.4 / 27.6
31 / 24.6 / 25.6 / -
MEAN / 26.3 / 26.2 / 26.3

DAY – TIME SEA SURFACE TEMPERATURE (SST) OVER

KOKO, DELTA STATE FOR July–Sept., 2012.

(DAILY AVERAGES IN °C)

DAY / July / August / Sept.
1 / 29.0 / 28.4 / 29.1
2 / 27.9 / 28.8 / 29.5
3 / 28.4 / 29.9 / 29.8
4 / 27.5 / 28.8 / 30.2
5 / 29.1 / 28.7 / 30.3
6 / 29.5 / 28.6 / 30.3
7 / 28.9 / 29.2 / 29.2
8 / 27.5 / 30.3 / 29.3
9 / 28.6 / 28.8 / 29.4
10 / 29.5 / 29.5 / 29.5
11 / 29.9 / 28.1 / 29.2
12 / 30.9 / 30.2 / 28.7
13 / 29.2 / 29.3 / 30.0
14 / 29.7 / 30.0 / 30.0
15 / 29.6 / 29.1 / 29.1
16 / 30.3 / 28.5 / 30.9
17 / 30.3 / 29.7 / 29.9
18 / 28.5 / 29.5 / 29.9
19 / 29.6 / 30.1 / 29.7
20 / 30.7 / 28.3 / 29.4
21 / 29.7 / 29.8 / 29.3
22 / 30.4 / 29.3 / 29.7
23 / 29.5 / 28.7 / 28.8
24 / 29.1 / 29.1 / 30.2
25 / 28.1 / 29.9 / 30.1
26 / 28.6 / 30.6 / 30.2
27 / 30.0 / 28.4 / 29.5
28 / 28.5 / 29.5 / 29.7
29 / 29.8 / 28.8 / 29.5
30 / 29.9 / 30.0 / 29.3
31 / 29.7 / 29.3 / -
MEAN / 28.3 / 29.3 / 29.6

DAY – TIME SEA SURFACE TEMPERATURE (SST) OVER Calabar,

CROSS RIVER STATE FOR July - Sept., 2012.

(DAILY AVERAGES IN °C)

DAY / July / August / September
1 / 27.1 / 25.4 / 25.8
2 / 27.3 / 25.7 / 25.8
3 / 26.9 / 25.4 / 25.6
4 / 26.9 / 25.5 / 25.7
5 / 27.1 / 25.4 / 25.5
6 / 26.9 / 25.4 / 25.7
7 / 26.4 / 25.5 / 25.6
8 / 26.7 / 25.5 / 25.6
9 / 26.5 / 25.6 / 25.6
10 / 26.4 / 25.7 / 25.8
11 / 26.5 / 25.7 / 26.1
12 / 26.8 / 26.0 / 26.1
13 / 26.6 / 26.3 / 26.3
14 / 26.6 / 26.3 / 26.4
15 / 26.4 / 26.3 / 26.6
16 / 26.7 / 26.5 / 26.3
17 / 26.7 / 26.5 / 26.5
18 / 26.5 / 26.3 / 26.8
19 / 26.1 / 26.6 / 26.6
20 / 26.3 / 26.2 / 26.7
21 / 25.6 / 26.4 / 26.9
22 / 25.5 / 26.1 / 26.6
23 / 25.6 / 26.4 / 26.7
24 / 25.7 / 25.8 / 26.5
25 / 25.5 / 25.8 / 26.8
26 / 25.5 / 25.9 / 27.2
27 / 25.5 / 25.9 / 27.6
28 / 25.5 / 25.9 / 27.2
29 / 25.5 / 26.0 / 27.2
30 / 25.4 / 25.9 / 27.2
31 / 25.4 / 26.1 / -
MEAN / 26.3 / 25.9 / 26.3

SAMPLE OF DAILY MARINE FORECAST

Inshore Waters Forecast to 20km Offshore

Issued by Nigerian Meteorological Agency (NIMET)

at 1500 UTC on Fri. 3rd Aug, 2012.

Period of Forecast: 1800 UTC Fri. 3rd to 1800 UTC Sat. 4th Aug, 2012.

General Situation: The coastal area of the country still remains under a ridging effect from St Helena’s high pressure cell with values from 1011 - 1014hPa. The system is expected to temporarily intensify to 1015hPa at 0900 UTC, thereafter weaken to its initial values till the end of forecast period. Convective activities are expected especially to the south east with light to fresh breeze.

Calabar, Eket and Port Harcourt Areas

24 Hr forecast

Wind: South - westerly, 5 -10kts occasionally 18kts.

Sea state: Moderate.

Weather: Rain, then thunderstorm.

Visibility: Moderate.

Outlook for the following 24hrs:

Wind: South-westerly, 5-12kts.

Sea State: Moderate.

Weather: Chances of rain.

Visibility: Moderate.

Warri, Koko and Aiyetoro Areas

24 hr forecast

Wind: South-westerly, 5 -10kts occasionally 15kts.

Sea State: Moderate.

Weather: Fair, chances of rain later.

Visibility: Moderate.

Outlook for the following 24hrs

Wind: South-westerly, 5 -10kts.

Sea State: Moderate.

Weather: Fair.

Visibility: Moderate.

Lagos Area: 24hr forecast:

Wind: South-westerly, 5 -10kts occasionally 15kts.

Sea State: Moderate to rough.

Weather: Fair, chances of isolated rain later.

Visibility: Moderate.

Outlook for the following 24hrs.

Wind: South- westerly, 5-10kts.

Sea State: Moderate.

Weather: Fair.

Visibility: Moderate.

End.

SHIPPING FORECAST TO 650KM OFFSHORE

ISSUED BY NIGERIAN METEOROLOGICAL AGENCY (NIMET),

at 1500 UTC on Fri. 3rd Aug, 2012.

VALID FOR: 1800 UTC Fri. 3rd to 1800 UTC Sat. 4th Aug, 2012.

WARNINGS: NIL

GENERAL SYNOPSIS: A ridge from St Helena’s high pressure cell will continue to dominate the Nigerian territorial waters with values ranging from 1013 - 1016hPa. The system will weaken to 1012hPa at around 1500 UTC and remain quasi stationary till the end of forecast period. The centre of St Helena’s high pressure system will fluctuate between 1024 – 1028hPa throughout the period of forecast. Little convective activities are expected with light to fresh breeze.

THE AREA FORECASTS FOR THE NEXT 24 HOURS:

WIND: SOUTH- WESTERLY, 5 –12KTS OCCASIONALLY 18KTS.

SEA STATE: MODERATE TO ROUGH.

WEATHER: FAIR, CHANCES OF RAIN.

VISIBILITY: MODERATE.

END.

WEATHER OUTLOOK FOR THE NEXT QUARTER (Oct – Dec, 2012)

The ITD positionwhich commenced its southward movement at the later part of the quarter (July-Sept, 2012) will continue to retreat, reaching its southernmost position toward the end of nextquarter (Oct.-Dec., 2012). This willleave major part of the country under the influence of dry dusty northeasterly wind which will reduce visibility in dust haze towards the end of the quarter.Rainfall will still be experienced in parts of the coastal area especially South-South due to coastal phenomenon. There will be chances of active waves whichmay result in storm surges. The sea surface temperature is expected to reach its second maximum peak around November to early December. There will be frequent early morning mist/ fog towards the end of this quarter which could disrupt coastal operations.