Forecast Report with Analog Years-Kenya

Introduction

This is a forecast report. The goal is to assist users in evaluating current forecasts in the context of past forecasts and to translate the forecast component into key assumptions about food security.

The report includes the following key components:

1. A verbal summary of assumptions based on the statistics in this forecast [NOT UPDATED]

2. Mean Area, Production, and Yield over the years 2009 to 2019:This provides context for interpreting the grain data

3. Historical Out of Sample Forecast Error Averaged Over a 10 Year+ Period. We show the Mean Absolute Percent Error (MAPE).

4. Yield Forecast, (based on April 2022 Precip, NDVI, Et0 ) expressed as percent of mean yield over the period 2009 - 2019.

5. Forecasts and Forecast Error in Analog Years We show specific forecasts and forecast error for years when the climate patterns are similar to what is expected in the current season.

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Summary Figures

Mean area, production, and yields for the years 2009 to 2019.

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Out of Sample Forecast Error (MAPE)

Mean Absolute Percent Error (MAPE) calculated based on historical out of sample seasonal forecasts. Lower scores indicate greater accuracy. Forecasts are based on model type MODEL¹

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Yield Forecast for April 2022

Forecast values expressed as percent of Mean Yields over the Years 2009 - 2019.

The figure shows predicted percent of mean (center) as well as lower (left) and higher (right) predicted percent of mean intervals.

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Static and Dynamic Version of Main Forecast

Roll over the polygon borders to get the district name and % of mean forecast value.

Static Version

This map shows the main % of mean forecast value along with district lables for reference.

This table shows the forecast percentage of mean values in the above table along with the mean yield values from the first figure.

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Table of Mean Yields and Predicted Percent of Mean Values

District	% of mean	% of mean (low)	% of mean (high)
Mombasa	101	74	127
Taita Taveta	22	0	51
Kiambu	88	63	113
Trans Nzoia	87	72	101
Uasin Gishu	113	100	127
Nakuru	103	90	116
Narok	101	76	127
Kakamega	124	104	143
Bungoma	127	121	134
Busia	103	82	124
Siaya	77	49	106
Kisumu	84	39	129
Homa Bay	84	57	112
Migori	73	45	102
Kisii	83	57	108
Nyamira	74	55	94

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Discrete Map

This map shows the main % of mean forecast binned into discrete values. Averages are based on the most recent 10 year period of observed yields: 2009 - 2019

Analog Year Forecasts

Yield forecasts in analog years. <–DESCRIPTION OF ANALOG YEAR PROCESS–>.
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Analog Year Forecasts Errors

Forecast errors in analog years. If observed data is not available in a given year we cannot calculate forecast errors. Values are expressed a percentage of observed yields in a given year (t):

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\[\frac{(observed_{(t)}-forecast_{(t)})}{observed_{(t)}}\] ***

Positive (+) values indicate an under prediction. Negative (-) values indicate an over prediction.

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1. Extra/Extended Trees. A type of Random Forest Model↩︎