Global overview: ENSO-neutral conditions will persist, with La Niña occurring in September and November and lasting throughout the Northern Hemisphere winter. Flooding in the Sahel, but drought in Ghana. Above-average rainfall in Central America.
Weather hazards in Africa
Floods continue to occur in East Africa and the Sahel region, and drought is looming in Ghana.
- Flooding is steadily increasing in the Sudd wetlands in South Sudan.
- Heavy and above-average rainfall has led to flooding in western, southern and eastern Sudan and western Ethiopia, causing casualties and damage. Thousands of people have been displaced in the Gambela region, where the Baro and Gilo rivers have burst their banks. Recent and forecast heavy rainfall is exacerbating flooding in northern Ethiopia and Eritrea. The upper reaches of the Shabelle River have risen above the “high danger” level in Somalia due to rainfall upstream.
- The water levels of the rivers in northern Angola are only slowly falling to normal levels.
- Eastern Liberia, Ivory Coast, Ghana, central Togo, central Benin, western and eastern Nigeria and central and eastern Cameroon are currently experiencing unusual dry conditions. The dry spell has significantly worsened soil conditions in northern Ghana, where drought is present. Eastern Nigeria and central and south-eastern Cameroon are experiencing drought conditions due to large deficits over the past two months.
- Heavy rains have caused deadly floods in Guinea-Bissau, Guinea (Conakry city), central and southern Mali (low-lying areas of Ségou, Sikasso and parts of Mopti), southern Niger, northern Nigeria (Sokoto and Komadugu rivers) and central and southern Chad. Flooding has occurred in coastal Guinea due to recent and forecast heavy rains. Flooding is expected along the Niger River in central and southern Nigeria this week.
- Unusually hot temperatures are forecast in Libya and Gabon.
Africa Overview
The area with the heaviest rainfall has shifted slightly further south in West Africa.
Over the past week, the heaviest rainfall shifted further south into areas of Guinea, Sierra Leone, northern Liberia, northern Ivory Coast, northern Togo, Benin, most of Nigeria, and Chad (Figure 1). Moderate rainfall continued in areas of southern Mauritania, central Mali, and southern Niger. Lighter rainfall was recorded in many locations along the Gulf of Guinea coast, as well as in northern Niger. The Sahel has experienced above-average rainfall over the past 30 days, particularly in Mali, northern Nigeria, and southern Niger. In contrast, drier-than-normal conditions are occurring in Ivory Coast, Ghana, Togo, Benin, Nigeria, and Cameroon, although some have improved. In Ghana, the dry spell negatively impacted local conditions. The Gulf of Guinea countries have also experienced unusually dry conditions over the past 90 days, with the largest deficits in eastern Nigeria and Cameroon.
Next week, the band of heavy and above-normal rainfall will again move northward across the Sahel. The highest 7-day rainfall amounts will be recorded in Guinea-Bissau, Guinea, Sierra Leone, northern Nigeria, and southern Niger. Heavy rain is also likely in Burkina Faso, southern Mali, Cameroon, and Chad. Light to moderate rainfall is expected along the Gulf of Guinea coast and in many areas of the Sahara. Unusual heat is expected in Libya. Heavy rains cause flooding in East Africa. Northern Ethiopia, Eritrea, southern and eastern Sudan, and northern South Sudan experienced heavy rainfall over the past week, with light to moderate rainfall across much of the rest of the region. Persistent abundant rainfall has already reportedly caused flooding in many areas, including eastern Sudan and many areas of northern Ethiopia. Over the past 30 days, much of the region has experienced above-average rainfall, except for western Ethiopia and small areas of eastern Sudan and western South Sudan. The highest surpluses (100 – 200 mm) were observed in western Sudan, northeastern Ethiopia, and parts of Sudan and South Sudan (Figure 2). Heavy and above-average rainfall is expected in northern and western Ethiopia and Eritrea next week. Moderate and still above-average rain (25 – 75 mm) is expected in Sudan, South Sudan, and Uganda. However, some parts of southwestern Ethiopia and western Kenya may experience slight deficits. Somalia may also see rain this week.
Central Asia Overview
Temperatures
Over the past week, average maximum temperatures were above average in some parts of eastern and western Kazakhstan, as well as in some parts of southern Turkmenistan and eastern Afghanistan. In contrast, average maximum temperatures were below average in northern and central Kazakhstan and northern Tajikistan. The hottest weekly average maximum temperatures of over 40°C were recorded in southern Afghanistan. Next week, the GEFS model forecasts above average 7-day average maximum temperatures in some parts of northwest Kazakhstan and eastern Tajikistan. In contrast, average 7-day maximum temperatures will be below average in northern, central, eastern and southern Kazakhstan, Uzbekistan, Turkmenistan and many parts of Afghanistan.
precipitation
Moderate to heavy rainfall was observed in northern and northeastern Kazakhstan, northeastern Kyrgyzstan, parts of eastern and southeastern Afghanistan, and northern Pakistan over the past week (Figure 3). Some parts of northern Kazakhstan and eastern Afghanistan received up to 50 mm of rainfall (Figure 3). Over the past 30 days, rainfall was above average in northwestern and northern Kazakhstan, northern Kyrgyzstan, and some parts of eastern Afghanistan (Figure 4). Over the next week, models predict moderate to heavy rainfall in northern and eastern Kyrgyzstan, eastern Tajikistan, some parts of eastern, southeastern, and northeastern Afghanistan, northern and northeastern Kazakhstan, and southern, southeastern (locally up to 150 mm), western, and northern Pakistan, and some parts of western Gujarat in India.
Yemen Overview
temperature
Below-average temperatures were observed in Yemen over the past week, particularly in the western half of the country. Lows were also mostly close to average, but there was an area of above-average temperatures in the northeast and below-average temperatures in the southeast. Below-average highs are expected in western Yemen next week.
precipitation
Heavy rainfall has resumed across Yemen over the past week, particularly heavy in western and central southern Yemen. High 7-day totals led to flooding in several western governorates. Widespread light to moderate rainfall was experienced in central regions of Yemen. Moderate rainfall is forecast for western Yemen next week. This is an improvement on rainfall over the past few weeks, but flooding continues. Moderate rainfall is forecast for southern Yemen, with light rain possible in central regions.
Central America Overview
Above-average rainfall is expected in southern Guatemala, El Salvador, Honduras and western Nicaragua.
During the last week, heavy rainfall (100 – 150 mm) was observed in Panama, Belize, eastern Guatemala and western Honduras. Slightly lower amounts but heavy rainfall (50 – 100 mm) were also recorded in northeastern Nicaragua, southeastern Honduras, southern Guatemala and El Salvador (Figure 5). Precipitation recorded in these areas was 25 – 100 mm above average, with the largest anomaly of 100 mm or more occurring in Belize. On the other hand, central Guatemala, northern Costa Rica and southern Nicaragua recorded 25 – 100 mm below average. During the last 30 days, heavy rainfall resulted in positive anomalies in most of Central America, eliminating the 30-day deficits recorded in northeastern Nicaragua and southeastern Honduras. On the other hand, rainfall deficits of 25 mm to 100 mm persisted in central Guatemala, while a new negative 30-day rainfall anomaly is emerging in the border regions of Costa Rica and northeastern Panama (Figure 6). GEFS forecasts indicate that northern Panama and coastal areas of Costa Rica will experience heavy but below-average rainfall over the next week. Western Nicaragua, the border region of El Salvador and Honduras, and southern Guatemala will receive above-average rainfall. Maximum temperatures will exceed 30 °C in northern Guatemala, Belize, El Salvador, eastern and northwestern Nicaragua, and southeastern Honduras. A heat hazard polygon has been established over southern and central Guatemala.
Overview of Hispaniola
Unusual heat likely in the south of the Dominican Republic and northeastern Haiti.
Light to moderate precipitation has been observed over the past 7 days across most of Haiti and the Dominican Republic. According to CPC Unified Gauge measurements, weekly precipitation values have ranged from 5 to 50 mm across most of the island. These precipitation amounts are close to the weekly average. Over the past 30 days, 10-50 mm above average precipitation has been observed across the island, which is more than 200% of the long-term average in most locations. For next week, forecasts indicate light to moderate precipitation across the eastern Dominican Republic and most of Haiti. It is very likely that a hybrid maximum temperature/heat index will exceed the 90th percentile for three consecutive days from the south-central Dominican Republic to northern Haiti.
Northern South America Overview
Unusual heat is expected in central and southern Colombia and central and northern Venezuela.
During the last week, northern and western Colombia continued to experience heavy rainfall of over 150 mm, while some areas of the Venezuelan states of Apure, Amazonas, and Bolivar experienced up to 100–150 mm of heavy rainfall (Figure 7). Weekly rainfall anomalies were 25–100 mm above average in the western highlands of Colombia and in isolated locations in southern and central Venezuela. On the other hand, northern Venezuela, the far west, and most of eastern Colombia experienced rainfall deficits of between 25 and 100 mm per week. These regions and southern Colombia experienced excessive deficits of 100–300 mm over the last 30 days, and even more in isolated locations. The erratic and below-average rainfall over the past 30 days has led to the creation and maintenance of polygons of abnormal dryness in southern and eastern Colombia and in the Venezuelan states of Lara, Portuguesa and Falcon (Figure 8). For the next week, forecasts indicate heavier (100 – 150 mm) and above-average rainfall in western and northern Colombia, and moderate to heavy (50 – 100 mm) rainfall in central and eastern Venezuela. Although these rainfall amounts are well below average in most of Venezuela (except the eastern regions) and in southern and eastern Colombia, persistent moderate rainfall in already saturated soils may lead to further flooding and landslides in the eastern highlands of Colombia and central Venezuela. There is a high probability (> 70%) that a hybrid maximum temperature/heat index will exceed the 90th percentile for at least three days in central and northern Venezuela and central and eastern Colombia.
