El Nino in East Africa: What a Wet Short-Rains Season Means for Supply Planning

Tony Miller

3 days ago

7 min read

As of ICPAC's August 2026 outlook, the October to December short rains are forecast to be wetter than normal across most of the Greater Horn of Africa, with a 90% chance of above-normal rain over southern Ethiopia, central to southern Somalia and north-eastern Kenya. The El Nino signal is regional, not continental, so stock to the forecast map, not to the headline.

What is the El Nino forecast for East Africa this season?

El Nino is established and still strengthening, and the regional centres have tied it directly to the short rains. NOAA's Climate Prediction Center, in its diagnostic discussion issued 10 September 2026, kept an El Nino Advisory in force and said El Nino is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter of 2026-27. NOAA's next discussion was scheduled for 8 October 2026, so anything below should be checked against that update.

The WMO's El Nino/La Nina Update, published 3 September 2026 with data to mid-August, put the likelihood of El Nino persisting through the end of 2026 and into February 2027 at close to 100%, and said it is expected to reach very strong intensity before peaking towards the end of the year. WMO also adds a caution that matters for buyers: the strength of an El Nino event does not translate directly into the size of impacts in any one region.

The regional translation comes from the IGAD Climate Prediction and Applications Centre (ICPAC). Its GHACOF74 technical statement, from the forum held 17 to 18 August 2026 in Kigali, gives the October to December (OND) outlook. ICPAC cites an 81% probability of a very strong El Nino (RONI of 2.0 or above) during October to December and a 97% probability that El Nino conditions persist into March to May 2027. The statement also expects the Indian Ocean Dipole to move towards a positive phase, and notes that El Nino events and a positive IOD are typically associated with above-normal OND rainfall over parts of the region.

Where is the wet signal strongest, and where is it not?

This is the part most "El Nino floods Africa" coverage gets wrong, so read the map. ICPAC's outlook, dated August 2026, says:

Strongest signal: a probability above 90% of above-normal rainfall over southern Ethiopia, central to southern Somalia and north-eastern Kenya.
Heavy totals: a probability above 90% of exceeding 400 mm over the season in parts of central to southern Somalia, central Kenya, the Lake Victoria Basin region, Burundi, western Rwanda and western Tanzania.
Onset: early to normal onset is more likely across eastern parts, including Somalia, central to eastern Kenya and most of Tanzania. The western parts of the region are forecast to see a delayed onset, consistent with El Nino reducing September rainfall before its impact turns wetter.
Exceptions: only isolated areas in cross-border parts of south-eastern Sudan and north-eastern South Sudan are expected to see depressed rainfall. A few regions in southern South Sudan carry a probability of up to 30% of exceeding 400 mm.

ICPAC is explicit that the outlook applies to seasonal timescales and large areas, and that dry spells can still occur within a wetter-than-normal season. The WMO's El Nino impacts on the Greater Horn of Africa release, dated 19 August 2026, carries the same warning in plainer terms: excessive rainfall substantially raises flood risk, which could mean loss of life, crop destruction, damage to critical infrastructure and an elevated risk of water- and vector-borne disease outbreaks. It also notes the upside, better pasture and water availability for livestock.

My view, as a supplier based in Juba: the forecast does not say South Sudan floods this OND. It says the east of the region is the most likely to take the heavy rain. A procurement team reading "El Nino" as "flood everywhere" will over-order for the wrong place and under-order for Kenya, Somalia and southern Ethiopia, where the forecast is strongest. Read your own country's zone in the GHACOF74 statement before you commit budget.

Why does the timing matter more than the forecast size?

Because the season has started, and an import ordered now does not arrive in time to matter. ICPAC's analogue years for 2026 are 1997 and 2023, both of which had wetter-than-normal OND rainfall across most of the region, though ICPAC stresses that analogues are not a replacement for the objective forecast. The practical point is simpler: the forecast was published in August, the season is beginning, and anything you still need for the first flood has to come from stock that already exists in the region.

That is the argument for in-country holdings, and it is the same one SLS made in its flood-season 2026 procurement checklist, written earlier in the year. If a ready quantity is not already in the pipeline by the time rain starts falling in your zone, the question is no longer what to order but what you can obtain from stock today.

What should supply teams pre-position for a wet short-rains season?

I would order the list by what fails first when a site floods, and by what SLS supplies from Juba stock. This is expertise, not a forecast; it follows the failure sequence on a flooded site.

Dewatering pumps. Standing water on a camp, clinic, warehouse floor or access road is the first problem. Trash pumps handle silt, debris and solids that clog a clean-water pump. Two Multiquip models cover most site work, both per the manufacturer's own data sheets: the QP3TH moves up to 1,500 litres per minute and passes solids to 37 mm, and the QP4TH moves up to 2,100 litres per minute, passes solids to 51 mm and has a maximum head of 28 metres. Buy for the solids in your water, not just the flow figure. Our guide to choosing a dewatering pump for flood response in East Africa covers the selection logic.
Hose, fuel and spares. A pump with no suction hose, strainer or fuel does nothing. Count them in the same order, not as an afterthought.
Point-of-use water treatment. WMO flags water-borne disease risk with excess rain. Floodwater turns source water turbid and contaminated, so household treatment has to cope with both turbidity and pathogens. That is where P&G Purifier of Water sachets and Aquatabs sit, and the choice between them depends on how turbid your sources become.
Storage that stays clean. Treated water needs somewhere safe to sit. Oxfam tanks and Butyl bladders are SLS lines; the sizing and siting decision is a separate piece of work.
Dry, raised storage for your own stock. If your supplies sit on the floor of a flood-prone store, your pre-positioning becomes the flood's inventory. Hallgruppen structures are another SLS line, and siting matters as much as the structure.

Why not just wait for the flood and respond?

Because a flood does not wait for your tender. Road access is the reason: when rain closes a route, you are no longer choosing a supplier, you are taking whatever is already on your side of the water. SLS holds stock in Juba and delivers in-country, which is the part of the chain that is not exposed to a sea freight leg or a port. That cannot protect every site, but it removes the longest single delay from the list, the import.

There is also a cost argument. The money spent on pre-positioned pumps and treatment is spent once, against a forecast that three separate bodies, NOAA, WMO and ICPAC, are broadly aligned on. Money spent after the event is spent on air freight and emergency premiums. I would rather defend a store of pumps that were not needed to a donor than explain why a clinic stood in water for a fortnight.

How should teams track the forecast as the season runs?

Treat the forecast as live and date every decision to it. NOAA's next discussion was due 8 October 2026, the WMO issues regular updates, and ICPAC will provide regional updates on a regular basis while national meteorological services publish country and sub-national forecasts. Reconcile your stock plan against each, and remember the caveat that cuts both ways: a wetter-than-normal season still contains dry spells, and a strong El Nino does not guarantee a proportionally strong impact.

Two habits help. First, tie each pre-positioned item to a trigger, such as a national met service advisory or a rise in a river gauge, so release is a decision and not a debate. Second, record what you held and what you used, so next season's order rests on your own data and not on a forecast alone.

Frequently asked questions

Is El Nino forecast to cause floods in East Africa in 2026?

It is forecast to make the October to December short rains wetter than normal across most of the region. ICPAC's GHACOF74 outlook gives a probability above 90% of above-normal rain over southern Ethiopia, central to southern Somalia and north-eastern Kenya, and the WMO says excessive rainfall substantially raises flood risk.

How strong is the current El Nino?

As of 10 September 2026, NOAA's Climate Prediction Center had an El Nino Advisory in force and gave a greater than 90% chance of a very strong event in the 2026-27 northern fall and winter. The WMO's August 2026 update put persistence through February 2027 at close to 100%.

Does El Nino mean heavy rain in South Sudan?

Not on the evidence of the outlook. ICPAC expects isolated depressed rainfall in north-eastern South Sudan and a delayed onset across the west of the region, with only a few southern areas showing up to a 30% chance of exceeding 400 mm. Check the South Sudan zone of the outlook and the national forecast before planning.

Which trash pump suits flood dewatering?

That depends on the solids in the water and the head you need. Per Multiquip's data sheets, the QP3TH passes solids to 37 mm at up to 1,500 litres per minute, and the QP4TH passes solids to 51 mm at up to 2,100 litres per minute.

When should supplies be pre-positioned for the short rains?

Before the season starts in your zone. ICPAC expects early to normal onset over much of the east, including Somalia, central to eastern Kenya and most of Tanzania, and a delayed onset in the west, so the eastern teams have the least time.