Seasonal Rainfall and Temperature Forecast for JJAS 2024

Rainfall forecast

The JJAS season is crucial for Sudan's rainfall, accounting for over 80% of the country's annual rainfall and exceeding 95% in central and northern regions. This season is vital for agricultural, pastoral, and water resource activities.

The forecast for this JJAS 2024 season (Figure 2) predicts rainfall with varying probability levels ranging from 55% to 65% above climatic averages in most states of the country.

A 65% probability of rainfall above climatic averages is predicted in some areas: (Western Red Sea State, Western Sennar State, Central Nile River State, and White Nile State, Central and Northern North Kordofan States, and Northern Darfur State). Most states in Sudan are expected to experience rainfall 55% above climatic averages, except for the northern parts of Red Sea State, Nile River State, Northern State, and Northern Darfur State, where rainfall is expected to be close to climatic averages.

Seasonal forecasts for the Ethiopian Highlands and Eritrea suggest a 45-55% likelihood of rainfall exceeding climatic averages during this season.

Analysis of standardized precipitation index (SPI) values for the four months ending on September 30, 2024, indicate a forecast of moderate to normal humidity in most states of Sudan.

Rainfall forecast

Forecasts for June 2024 (Figure 3) indicate an increased chance of rainfall within the range of average to below average in the states of (Blue Nile, East, and West, and Central Darfur, and the western parts of West Kordofan), and above climatic averages in the states of South Kordofan and West Kordofan.

Rainfall forecast

(A) Average model dates for the start of the rainy season (June- September) 2024, (B) The climatic average for the start date of the season (June - September) 2024

Rainfall forecast

A normal start to the rainy season is expected this year (June-September) 2024 (Figure: 7, 8): in most states of Sudan, with relatively early starts in some scattered areas in several states and relatively late starts in West and Central Darfur.

Rainfall forecast

The results of the analysis of the standardized precipitation index for the period from the beginning of June to the end of September 2024 indicates moderate moisture conditions during this season in Sudan.

Rainfall forecast

Figure 10: (A) Deviations from the model average for the duration of wet spell periods after the start of the June-September 2024 season, (B) The model average for the longest initial wet spell after the start, (C) Deviations from the model average for the start of wet spell periods after the start of the June-September 2024 season, (D) Dates of the longest peak wet spell after the start of the June-September 2024 rainy season.

Rainfall forecast

Figure 11: (A) Deviations from the model average for the duration of dry spell during the June-September 2024 season, (B) The model average for the first longest dry spells after the start of the June-September 2024 rainy season, (C) Deviations from the model average for the duration of dry spells after the start of the June-September 2024 season, (D) The model average for the dates of the first dry spells after the start of the June-September 2024 rainy season.

Rainfall forecast

Figure 1: Climatic Averages of Rainfall for Different Regions of Sudan

أ- أشارت توقعات حالة البحار العالمية والمحيط الهندي وهي من العوامل األساسية المؤثرة على

المناخ الموسمي إلى انتقالها من حالة إرتفاع درجة حرارة سطح المحيطات اإلستوائية أعلى من

المتوسط )ظاهرة النينو( إلى إلى حالة التعادل، و ترتبط ظاهرة النينو بشح األمطار وحاالت

الجفاف في مناطق دول شمال القرن األفريقي بما فيها السودان، كما ،أشارت التوقعات

إلى انتقال حالة التعادل إلى حالة إنخفاض درجة حرارة سطح المحيطات اإلستوائية أقل من

المتوسط )النينا( حتى نهاية صيف هذا العام، وترتبط ظاهرة الالنينا بحاالت الرطوبة العالية

وهطول األمطار الغزيرة )تختلف درجة الرطوبة وكميات األمطار حسب قوة الظاهرة(.

ب- كما أشارت توقعات حالة المحيط الهندي إلى إرتفاع درجة حرارة غرب المحيط الهندي

أعلى من المتوسط، وانخفاضها أقل من المتوسط في شرق المحيط وهي الحالة الموجبة للمحيط

الهندي، تتحول هذه إلى حالة التعادل بنهاية الموسم، مما قد يدعم هطول أمطار غزيرة في شمال

وشرق القرن األفريقي بما في ذلك السودان.ج- خالل هذا الموسم يتوقع هطول أمطار أعلى من المعدالت المناخية بنسب متفاوتة في معظم

واليات السودان.

د- كذلك يتوقع حدوث درجات حرارة سطحية أعلى من المعدالت المناخية بنسب عالية، تزداد

درجات الحرارة تجاه شمال البالد لتصل أعالها في شرق البالد)والية البحر األحمر(، شمال

البالد وشمال غرب البالد)واليات الشمالية، نهر النيل، شمال دارفور(.

ه- يتوقع حالة رطوبة في حدود المعدالت المناخية إلى أعلى قليال في معظم واليات السودان

و- كما يتوقع بداية طبيعية لهذا الموسم )يونيو- سبتمبر(2024م، كذلك يتوقع أن يتحرك حزام

المطر شماال ليستقر في مناطق وسط البالد بداية شهر سبتمبر.

ز- سوف تعمل الهيئة على تحديث هذا التوقع شهريا ونشر أي مستجدات تطرأ عليه.

ط-أعلى درجات المتوقعة لهذا الموسم في شهر )يونيو ويوليو( في واليات البحر األحمر، نهر

النيل، الشمالية وشمال دارفور وأدناها خالل شهري أغسطس وسبتمبر(، في واليات القضارف،

كسال، الخرطوم والنيل األبيض.

Rainfall forecast

Forecasts for July 2024 (Figure 4) indicate an increased chance of rainfall within the range of climatic average to below average in the states of (Blue Nile, the extreme south of South Kordofan, and the western parts of South Darfur and West Darfur) and above climatic averages with a 40-70% probability in the remaining states of the country.

Rainfall forecast

Forecasts for August 2024 (Figure 5) indicate an increased chance of rainfall within the range of average to below average in the states of (West and Central Darfur, and the south of Blue Nile) and above climatic averages with a 40-70% probability in all other states of the country.

Rainfall forecast

Forecasts for September 2024 (Figure 6) indicate an increased chance of rainfall within the range of average to below average in the states of (West Kordofan, Central, and West Darfur), and within the range of climatic averages and above climatic averages with a 40-70% probability in all other states of the country.

Temperature forecast

During this season, there is a (60-90%) probability that the average temperature will be higher than the climatological average in most states of Sudan, and a (90-95%) probability that it will be higher than the climatological average in Red Sea State, Northern State, River Nile State, and North Darfur State (see Figure 12). June 2024 is expected to be the hottest month of the season, while August is expected to be the coolest.

Temperature forecast

8.1. June 2024:

During this month, there is a (60-90%) probability that the average temperature will be higher than the climatological average in most states of Sudan, and a (90-95%) probability that it will be higher than the climatological average in Red Sea State, Northern State, River Nile State, and North Darfur State. June 2024 is expected to be the hottest month of the season (see Figure 13).

8.2. July 2024:

During this month, there is a (60-90%) probability that the average temperature will be higher than the climatological average in the states of Red Sea, River Nile, Northern and North Darfur, and a (40-60%) probability that it will be higher than the climatological average in the rest of Sudan's states (see Figure 13). The states of Gedaref, the southern parts of Kassala, Sennar, and White Nile will have the lowest temperatures during this month.

8.3. August 2024:

During this month (see Figure 13), there is a (60-90%) probability that the average temperature will be higher than the climatological average in the extreme north of the states of Red Sea, River Nile, Northern, and North Darfur. There is also a (40-60%) probability that it will be higher than the climatological average in the states of Blue Nile, East, South and Central Darfur, the southern regions of South and West Kordofan, the Red Sea and River Nile states, the central regions of North Kordofan and North Darfur, and within the normal to lower range in the states of Kassala, Gedaref, Sennar, Gezira, White Nile and Khartoum.The northern parts of South and West Kordofan and South Darfur are expected to have temperatures within the climatological average.

8.4. September 2024:

During this month (see Figure 13), there is a (60-90%) probability that the average temperature will be higher than the climatological average in the extreme north of the states of Red Sea, River Nile, Northern, and North Darfur. There is also a (40-60%) probability that it will be higher than the climatological average in the states of Blue Nile, East, South and Central Darfur, the southern regions of South and West Kordofan, the Red Sea and River Nile states, the central regions of North Kordofan and North Darfur, and within the normal to lower range in the states of Kassala, Gedaref, Sennar, Gezira, White Nile and Khartoum.

The northern parts of South and West Kordofan and South Darfur are expected to have temperatures within the climatological average. June is expected to be the hottest month of the season followed by July. August is expected to be the coolest month followed by September.

Gedaref State is expected to be the coolest state in Sudan during this season.

A. The global and Indian Ocean sea state forecasts, which are key factors influencing the seasonal climate, have indicated a transition from a state of higher than average equatorial ocean surface temperatures (El Niño) to a neutral state. El Niño is associated with reduced rainfall and drought conditions in areas of North Horn of Africa countries, including Sudan. The forecasts also indicated a transition from a neutral state to a state of lower than average equatorial ocean surface temperatures (La Niña) by the end of this summer. La Niña is

associated with high humidity and heavy rainfall (the level of humidity and amount of rainfall vary depending on the strength of the phenomenon).

B. As the Indian Ocean Dipole (IOD) forecast indicates a warmer-than-average Western Indian Ocean and a cooler-than-average Eastern Indian Ocean, reflecting a positive IOD, this condition will transition to neutral by the end of the season. This shift could support heavy rainfall in northern and eastern parts of the Horn of Africa, including Sudan.

C. During this season, rainfall is anticipated to be above the climatological averages in most Sudanese states with varying proportions.D. Surface temperatures are also expected to be higher than the climatological averages by significant percentages. Temperatures will increase towards the north, reaching their highest levels in the east (Red Sea State), north (Northern and Nile States), and northwest (North Darfur State).

E. Humidity levels are expected to be within or slightly above the climatological averages in most Sudanese states.

F. A normal start to the season (June-September) 2024 is anticipated. The rain belt is expected to move northward, reaching central regions by early September.

G. The Authority will update this forecast monthly and publish any emerging developments.

H. The highest temperatures for this season are expected in June and July in the Red Sea, Nile, Northern, and North Darfur states. The lowest temperatures are anticipated during August and September in the Gedaref, Kassala, Khartoum, and White Nile states.

Note: The Authority will update and publish this forecast on monthly basis.