Africa Briefing April 26, 2011 Miliaritiana Robjhon miliaritiana.robjhon@noaa

1. Africa BriefingApril 26, 2011Miliaritiana Robjhonmiliaritiana.robjhon@noaa.gov • Localized heavy rains continued during the past seven days • Little to no rain over northern Kenya, northern Tanzania, and Somalia

2. 7-day and 30-day rainfall anomaly (mm) Last week This week 7-day Seasonal rainfall amounts only observed over localized areas Otherwise, dryness prevailed over much of eastern Africa Rainfall deficits [50-100mm] 30-day

3. Seasonal rainfall anomaly

4. Number of rain days during the last 30 days Southwestern Ethiopia, southwestern and eastern Kenya received more than 15 rain days during the last 30 days Areas affected by significant negative anomalies: Southern Ethiopia and central Kenya

5. Reduced actual evapotranspiration during the first 3 months of 2011, accounting for only 50-70% of the 2000-2010 average • Stressed vegetation, with NDVI anomalies between -0.2 to -0.1 during Apr 6- 15, 2011 NDVI APR 6 – 15, 2011 SOURCE: Jim Rowland SOURCE: Jim Rowland

6. Population density – LST anomaly – RFE anomaly: Mar 2011 Areas with dense population affected by dryness in the GHA Land Surface Temperature (LST) Anomaly RFE Anomaly Population Density SOURCE: USGS/EWX Dry conditions prevailed over southern Ethiopia, southern Somalia, and northern and central Kenya, with deficits ranging between 10-50mm Warmer central Kenya and eastern Ethiopia, with above-average LST between 6-7⁰ during the past month Based on analysis by Chris Funk

7. Central Kenya: Mar-Apr contributes to 80% of Mar-Jun totals SOURCE: Gideon Galu SOURCE: Chris Funk For Kenya, rainfall received during Mar-Apr is critical for seasonal rainfall performance

8. Concerns for Central & Eastern Kenya If the rest of the seasonal is normal (which is probably unlikely), central Kenya will have seasonal totals 24% below normal. If the season is plays out like 2009, Central Kenya might receive ~40% below normal. Central Province } Green: average Red: 2009 Blue: 2011 If the rest of the seasonal is normal (which is probably unlikely), central Kenya will have seasonal totals 23% below normal. If the season is plays out like 2009, Central Kenya might receive ~50% of normal. SOURCE: Chris Funk Eastern Province So far, the season matches 2009 exactly Short Term Mean } By 1st Dekad of May, Rainfall rates drop rapidly 2011 2009 http://earlywarning.usgs.gov:8080/EWX/index.html

9. ITF Analysis ITF lagged behind the average position during the 2nd dekad of Apr

10. WRSI and SWI 1 Dekad of APR 2 Dekad of APR

11. Rainfall forecast for GHA

12. Heavy downpours continued in western southern Africa

13. 7-day and 30-day rainfall anomaly Last week This week 7-Day 30-Day

14. Rainfall percent normal & Basin excess rainfall map

15. Rainfall forecast for southern Africa

16. West Africa Heaviest rains over southeastern Nigeria and Cameroon Heavy rains across northern Ghana, Togo, and Benin

17. 7-day and 30-day rainfall Anomaly (mm) This week Last week 7-Day 30-Day

18. Rainfall forecast for West Africa

19. La Nina expected to weaken toward a return to ENSO-neutral Climate Forecast System (CFS) at 1-month lead Canonical Correlation Analysis (CCA)at 1-month lead

20. Current Conditions

21. Africa hazards assessment