Climate Forecasts

CLIMATE FORECAST

The Climate Hazards Center (CHC) of the University of California Santa Barbara (https://www.chc.ucsb.edu/) provides GEOGLAM Crop Monitor with global and regional climate outlooks. These assessments are based on weather and seasonal climate forecasts from a variety of international and national sources. Regional climate outlooks in the CM4EW draw attention to abnormal rainfall and temperature conditions (observed and forecast) that may impact food production or pose other risks to society, with a focus on food insecure regions.

 

May 7th, 2020
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For previous reports visit the Archive.

Global Climate Outlook

ENSO neutral conditions likely to continue through summer 2020

El Niño-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) conditions are currently neutral and are expected to remain neutral through the northern hemisphere summer. However, there is an elevated chance of La Niña or La Niña-like climate arising by October. Such conditions are associated with the combined influence of abnormally cool equatorial East Pacific sea surface waters and abnormally warm sea surface waters in the western Pacific. La Niña or La Niña-like conditions during October-December typically reduce rainfall in East Africa, Central Southwest Asia, southern Brazil and central Argentina, and increase rainfall in Southern Africa, Australia, and eastern Brazil.

East Africa Outlook:

Above-average rainfall expected to continue across much of the region through May

After one of the wettest January-March stretches since 1981, above average rainfall continued across much of the region through April, with surpluses exceeding 100mm (>200% of the historical average) in western and eastern Tanzania, Rwanda, Burundi, Kenya, and Ethiopia. The above average rain since January resulted in flooding throughout much of the region, displacing many individuals and supporting continued spread of locust swarms. April rainfall was average to below average in northwestern Uganda, South Sudan and northwestern Ethiopia, with deficits of 25-50mm (<80% of the historical average).

Both short- (15-day; not shown) and medium-term (30-day; figure 1-right) forecasts indicate the April rainfall pattern is likely to continue through May, with continued above average rainfall in Rwanda, Burundi, western Tanzania, Uganda, western Kenya, southern Ethiopia and Somalia; below average rainfall is expected to continue in South Sudan and western Ethiopia. Figure 1-middle shows how the 15-day forecasted rainfall could affect the April anomaly. While rainfall deficits of 25-100mm below average (50-85% of average) may be experienced in parts of northern Uganda, South Sudan and northwestern Ethiopia, rainfall is expected to be well above average in Tanzania, Kenya, central and eastern Ethiopia, and Somalia.

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Figure 1. Estimated and forecast rainfall since April 1st and a 30-day forecast. All three maps depict rainfall in terms of the difference from average. The left panel is the UCSB Climate Hazards Center Early Estimate for April 1st to April 30th, based on preliminary CHIRPS. The middle panel is an extended outlook. It shows how the post-April 1st anomaly will change if the 15-day unbiased GEFS forecast from April 30th materializes. These compare 2020 rainfall amounts to the 1981-2019 CHIRPS average. On the right is a 30-day forecast from April 30th. The image shows the average of four Subseasonal Experiment (SubX) model forecasts from that day. The anomaly is based on the 1999 to 2016 model average. Skill assessments of SubX can be accessed at http://cola.gmu.edu/kpegion/subx/index.html.

 

Middle East and North Africa:

Average to above-average rainfall is expected through the start of May in the Middle East and North Africa

April rainfall was above average in northeastern Morocco, northern Algeria, northern Tunisia and the Middle East. As seen since late December, rains remained below average in southern Morocco (Figure 1-top). Correspondingly, as winter wheat ripening and harvesting begins, prospects are dismal in the west (particularly in Morocco) and favorable in eastern North Africa and the Middle East.

Short term (15-day) forecasts for the first 15 days of May indicate a continuance of average to above-average rainfall in northern Morocco and northwestern Algeria, and a return to below-average average in southern Morocco, northeastern Algeria, and northern Tunisia. Above-average rainfall is expected to continue in the Middle East, providing favorable conditions for winter wheat (currently in the ripening stage). Longer-term forecasts for the remainder of May and beyond are inconclusive.

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Figure 1. Both maps are Climate Hazards Center Early Estimates depicting recent rainfall as a difference from the 1981-2019 CHIRPS average. The top panel is the estimated rainfall from April 1st to April 30th, based on preliminary CHIRPS. The bottom panel is an extended outlook. It shows how the post-April 1st rainfall anomaly will change if the 15-day GEFS forecast from April 30th materializes.

Southeast Asia Outlook:

Below-average rains are forecast to continue in northern Southeast Asia through May while above-average rains are expected in Indonesia

April rainfall was substantially below average over much of Indochina, eastern Malaysia, and the Philippines (Figure 1-left), with deficits of 25-100mm across Myanmar, Laos, Thailand, Cambodia, and Vietnam, and deficits of 100-200mm in eastern Malaysia and the southern Philippines (< 50% of the historical average). April rainfall was average to above average across southwestern Indonesia (~120-150% of average).

Short- and medium-term forecasts predict below-average rainfall will continue in the northern half of the region through May, while above average rains are expected to continue in the south. If the 15-day forecast indicating below-average rainfall materializes, negative anomalies for April 1st to May 15th could exceed 50 mm across Laos, Thailand, Cambodia, Vietnam, and the northern Philippines (Figure 1-middle), and the 30-day forecast for the month of May indicates these deficits are likely to increase (Figure 1-right). In Malaysia and Indonesia, above-average rainfall is expected through May, which will benefit development of the second rice season. Rainfall forecasts beyond May are inconclusive.

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Figure 1. Estimated and forecast rainfall since April 1st and a 30-day forecast. All three maps depict rainfall in terms of the difference from average. The left panel is the UCSB Climate Hazards Center Early Estimate for April 1st to April 30th, based on preliminary CHIRPS. The middle panel is an extended outlook. It shows how the post-April 1st anomaly will change if the 15-day unbiased GEFS forecast from April 30th materializes. These compare 2020 rainfall amounts to the 1981-2019 CHIRPS average. On the right is a 30-day forecast from April 30th. The image shows the average of four Subseasonal Experiment (SubX) model forecasts from that day. The anomaly is based on the 1999 to 2016 model average. Skill assessments of SubX can be accessed at http://cola.gmu.edu/kpegion/subx/index.html.

Central America & Caribbean:

Above-average rains expected in the first half of May across much of the region.

April rains in Central America were below average across much of the region with deficits of 25-50 mm across the entire region, and exceeding 100 mm below average in eastern Cuba and Haiti, equating to less than 50% of the average rainfall.

While short-term forecasts (not shown) indicate average- to above-average rainfall is expected across most of the region for the first half of May, the expected rainfall would not be enough to offset April deficits. Figure 1-left indicates how the 15-day anticipated rainfall could impact the post-April 1st total anomaly. Most of the region is expected to remain average to below average. The areas of greatest concern are eastern Honduras, eastern Nicaragua, eastern Cuba, and Haiti (<75% of average). The 30-day forecast (Figure 1-middle) indicates rainfall in Honduras, Nicaragua, and Haiti will likely continue to be below average for the remainder of May. Longer-term forecasts suggest above-average rainfall is likely for the month of June in Guatemala, western Honduras, and western Nicaragua (Figure 1-right). Elsewhere in the region, the long-term forecasts are inconclusive (colored white). Although still very early in the season, this delayed start to the rains comes on the heels of five consecutive years of poor Primera season yields, which has resulted in considerable food insecurity in the region.

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Figure 1. Estimated and forecast rainfall since April 1st. The left and middle maps depict rainfall in terms of the difference from average. The left panel is the extended outlook for April 1st to May 15th.. This Climate Hazards Center Early Estimates are based on preliminary CHIRPS for April, and the 15-day unbiased GEFS forecast from May 1st. This graphic compares 2020 rainfall amounts to the 1981-2019 CHIRPS average. The middle panel is a 30-day forecast from April 30th. The image shows the average of four Subseasonal Experiment (SubX) model forecasts from that day. The anomaly is based on the 1999 to 2016 model average. Skill assessments of SubX can be accessed at http://cola.gmu.edu/kpegion/subx/index.html. The right panel is the NMME probabilistic forecast for the month of June based on April conditions.

For previous forecasts and assessments, please see the report archive page.