Drivers of Subseasonal Forecast Errors of the East African Short Rains

The ‘short rains’ in East Africa from October to December have significant year-to-year variability. Their abundance or deficiency is often associated with floods or droughts for which early warning is crucial, though even in normal seasons skillful forecasts facilitate planning and preparedness. He...

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Autores principales: Kolstad, Erik Wilhelm, Macleod, David, Demissie, Teferi Dejene
Formato: Journal Article
Lenguaje:Inglés
Publicado: American Geophysical Union 2021
Materias:
Acceso en línea:https://hdl.handle.net/10568/114899
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author Kolstad, Erik Wilhelm
Macleod, David
Demissie, Teferi Dejene
author_browse Demissie, Teferi Dejene
Kolstad, Erik Wilhelm
Macleod, David
author_facet Kolstad, Erik Wilhelm
Macleod, David
Demissie, Teferi Dejene
author_sort Kolstad, Erik Wilhelm
collection Repository of Agricultural Research Outputs (CGSpace)
description The ‘short rains’ in East Africa from October to December have significant year-to-year variability. Their abundance or deficiency is often associated with floods or droughts for which early warning is crucial, though even in normal seasons skillful forecasts facilitate planning and preparedness. Here we study the relationship between initial-state sea surface temperatures and subseasonal rainfall forecast errors in the European Center for Medium-Range Weather Forecasts model in the region. We demonstrate that the initial mode of the Indian Ocean Dipole (IOD) is a partial control on the rainfall error in weeks 3–4. This relationship is also clear on the seasonal scale, exemplified by too-wet forecasts during the 2015 season when the IOD was positive, and too-dry forecasts in 2010 when it was negative. Our results provide an entry point for model improvement, and we show that a priori forecast corrections based on the initial IOD index are feasible.
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spelling CGSpace1148992025-08-15T13:22:34Z Drivers of Subseasonal Forecast Errors of the East African Short Rains Kolstad, Erik Wilhelm Macleod, David Demissie, Teferi Dejene forecasting rain agriculture food security climate change The ‘short rains’ in East Africa from October to December have significant year-to-year variability. Their abundance or deficiency is often associated with floods or droughts for which early warning is crucial, though even in normal seasons skillful forecasts facilitate planning and preparedness. Here we study the relationship between initial-state sea surface temperatures and subseasonal rainfall forecast errors in the European Center for Medium-Range Weather Forecasts model in the region. We demonstrate that the initial mode of the Indian Ocean Dipole (IOD) is a partial control on the rainfall error in weeks 3–4. This relationship is also clear on the seasonal scale, exemplified by too-wet forecasts during the 2015 season when the IOD was positive, and too-dry forecasts in 2010 when it was negative. Our results provide an entry point for model improvement, and we show that a priori forecast corrections based on the initial IOD index are feasible. 2021-07-28 2021-09-07T13:14:42Z 2021-09-07T13:14:42Z Journal Article https://hdl.handle.net/10568/114899 en Open Access American Geophysical Union Kolstad EW, MacLeod D, Demissie TD. 2021. Drivers of Subseasonal Forecast Errors of the East African Short Rains. Geophysical Research Letters 48(14):e2021GL093292..
spellingShingle forecasting
rain
agriculture
food security
climate change
Kolstad, Erik Wilhelm
Macleod, David
Demissie, Teferi Dejene
Drivers of Subseasonal Forecast Errors of the East African Short Rains
title Drivers of Subseasonal Forecast Errors of the East African Short Rains
title_full Drivers of Subseasonal Forecast Errors of the East African Short Rains
title_fullStr Drivers of Subseasonal Forecast Errors of the East African Short Rains
title_full_unstemmed Drivers of Subseasonal Forecast Errors of the East African Short Rains
title_short Drivers of Subseasonal Forecast Errors of the East African Short Rains
title_sort drivers of subseasonal forecast errors of the east african short rains
topic forecasting
rain
agriculture
food security
climate change
url https://hdl.handle.net/10568/114899
work_keys_str_mv AT kolstaderikwilhelm driversofsubseasonalforecasterrorsoftheeastafricanshortrains
AT macleoddavid driversofsubseasonalforecasterrorsoftheeastafricanshortrains
AT demissieteferidejene driversofsubseasonalforecasterrorsoftheeastafricanshortrains