The African Monsoon Recent Evolution and Current Status Include Week-1 and Week-2 Outlooks

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The African Monsoon Recent Evolution and Current
StatusInclude Week-1 and Week-2 Outlooks
Update prepared by Climate Prediction Center /
NCEP 04 February 2013
For more information, visit http//www.cpc.ncep.n
oaa.gov/products/Global_Monsoons/African_Monsoons/
precip_monitoring.shtml
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Outline

• Highlights
• Recent Evolution and Current Conditions
• NCEP GEFS Forecasts
• Summary

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HighlightsLast 7 Days

• Weekly total rainfall exceeded 160mm over
  portions of northern Mozambique, the Comoros
  Islands, Madagascar, and local areas in Malawi.
• Suppressed rainfall prevailed over much of
  Zambia, Zimbabwe, Botswana, Namibia and southern
  Mozambique.
• Week-1 outlooks call for an increased chance for
  above-average rainfall over parts of South
  Africa, and much of Madagascar. In contrast,
  there is an increased chance for below-average
  rainfall over much of Tanzania and the
  neighboring areas of Mozambique and Malawi.

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Rainfall Patterns Last 7 Days
During the past seven days, above average
rainfall was observed over much of Congo, parts
of DRC, Angola, Rwanda, Burundi, local areas in
Uganda, many parts of Tanzania, Southwest Kenya,
northern Mozambique, local areas in South Africa,
and much of Madagascar. Local areas in Angola and
DRC, portions of Namibia, Botswana, much of
Zimbabwe, Zambia, southern Mozambique, and local
areas in Madagascar received below average
rainfall.
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Rainfall Patterns Last 30 Days
During the past 30 days, below-average rainfall
was observed over southern Gabon, southern Congo,
much of Angola, Namibia, portions of DRC,
southern Botswana, Namibia, portions of South
Africa, southern Uganda, parts of Tanzania, local
areas in Kenya, and many parts of Madagascar. In
contrast, local areas in Nigeria, southern CAR,
local areas in DRC and Angola, southern Zambia,
northern Botswana, much of Zimbabwe and
Mozambique, southern Tanzania, and local areas in
Madagascar received above-average rainfall.
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Rainfall Patterns Last 90 Days
During the past 90 days, local areas in Guinea,
Sierra Leone, local areas in Ghana, Nigeria and
Cameroon, northern Gabon, portions of DRC, local
areas in Angola, portions of Zambia, Uganda,
portions of Kenya, local areas in Tanzania,
portions of Mozambique, local areas in Zimbabwe,
northeastern South Africa, and local areas in
Madagascar received above average rainfall. In
contrast, rainfall was below-average over parts
of Gabon and DRC, local areas in Angola, parts of
Botswana, Namibia and South Africa, local areas
in Kenya, Somalia and Tanzania, and much of
Madagascar.
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Rainfall Patterns Last 180 Days
During the past 180 days, rainfall was
above-average over local areas in Senegal,
southern Mauritania, parts of Mali, Guinea
Bissau, Guinea, Sierra Leone, portions of
Liberia, local areas in Cote dIvoire, parts of
Burkina Faso, Ghana, portions of Nigeria, local
areas in Niger, southern Chad, northern Cameroon,
much of CAR, portions of Gabon and DRC, portions
of Angola, South Sudan, Uganda, local areas in
Kenya and Ethiopia, parts of Zambia, central and
southern Mozambique, eastern South Africa and
portions of Madagascar. Local areas in Cameroon,
portions of DRC, local areas in Ethiopia,
portions of Kenya, local areas in southern
Somalia, local areas in Namibia, South Africa,
and portions of Madagascar had below average
rainfall.
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Recent Rainfall Evolution
Daily evolution of rainfall over the last 90 days
at selected stations reflects the recent moderate
to heavy rainfall that helped to erode some of
the moisture deficits over parts of Tanzania,
(bottom panel left) and Madagascar (top
panel-right). Seasonal rainfall showed a
decreasing trend recently over portions of
Zimbabwe (bottom panel right).
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Atmospheric CirculationLast 7 Days
The 850hPa wind anomaly (left panel) featured
anomalous southerly winds from the Indian Ocean
across northern Mozambique and Tanzania, which
may have contributed to the observed moderate to
heavy rainfall in the region. The 200hPa wind
anomaly (right panel) featured anomalous
upper-level cyclonic flow near South Africa.
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NCEP GEFS Model ForecastsNon-Bias Corrected
Probability of precipitation exceedance Week-1
Valid 05 11 February 2013Week-2 Valid 12 18
February 2013
For week-1 (left panel) and week-2 (right panel),
there is an increased chance for rainfall to
exceed 50 mm over parts of Angola, Zambia,
Malawi, Mozambique and Madagascar.
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Experimental Week-1 Precipitation Outlooks
05 11 February 2013

1. There is an increased chance for above-average
   rainfall over parts of South Africa Lower level
   wind convergence is expected to enhance rainfall
   in the region. Confidence Moderate
2. There is an increased chance for below-average
   rainfall over much of Tanzania and the
   neighboring areas of Mozambique and Malawi The
   projected phase of the MJO is expected to
   suppress rainfall in the region. Confidence
   Moderate
3. There is an increased chance for above-average
   rainfall over much of Madagascar Anomalous lower
   level cyclonic circulation is expected to enhance
   rainfall in the region. Confidence Moderate

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Experimental Week-2 Precipitation Outlooks
12 - 18 February 2013

1. There is an increased chance for above-average
   rainfall over western Zambia, and the neighboring
   areas of Angola and Zimbabwe Anomalous easterly
   winds from the Indian Ocean, with their
   associated convergence are expected to enhance
   rainfall in the region. Confidence Moderate
2. There is an increased chance for below-average
   rainfall over Northeast South Africa and the
   neighboring areas of Southeast Botswana, northern
   Zimbabwe and southern Mozambique Combination of
   anomalous lower level anti-cyclonic flow and
   upper level cyclonic circulation is expected to
   suppress rainfall in the region. Confidence
   Moderate
3. There is an increased chance for above-average
   rainfall over the much of Madagascar Anomalous
   lower level cyclonic circulation is expected to
   enhance rainfall in the region. Confidence
   Moderate

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Summary

• During the past seven days, above average
  rainfall was observed over much of Congo, parts
  of DRC, Angola, Rwanda, Burundi, local areas in
  Uganda, many parts of Tanzania, Southwest Kenya,
  northern Mozambique, local areas in South Africa,
  and much of Madagascar. Local areas in Angola and
  DRC, portions of Namibia, Botswana, much of
  Zimbabwe, Zambia, southern Mozambique, and local
  areas in Madagascar received below average
  rainfall.
• During the past 30 days, below-average rainfall
  was observed over southern Gabon, southern Congo,
  much of Angola, Namibia, portions of DRC,
  southern Botswana, Namibia, portions of South
  Africa, southern Uganda, parts of Tanzania, local
  areas in Kenya, and many parts of Madagascar. In
  contrast, local areas in Nigeria, southern CAR,
  local areas in DRC and Angola, southern Zambia,
  northern Botswana, much of Zimbabwe and
  Mozambique, southern Tanzania, and local areas in
  Madagascar received above-average rainfall.
• During the past 90 days, local areas in Guinea,
  Sierra Leone, local areas in Ghana, Nigeria and
  Cameroon, northern Gabon, portions of DRC, local
  areas in Angola, portions of Zambia, Uganda,
  portions of Kenya, local areas in Tanzania,
  portions of Mozambique, local areas in Zimbabwe,
  northeastern South Africa, and local areas in
  Madagascar received above average rainfall. In
  contrast, rainfall was below-average over parts
  of Gabon and DRC, local areas in Angola, parts of
  Botswana, Namibia and South Africa, local areas
  in Kenya, Somalia and Tanzania, and much of
  Madagascar.
• Week-1 outlooks call for an increased chance for
  above-average rainfall over parts of South
  Africa, and much of Madagascar. In contrast,
  there is an increased chance for below-average
  rainfall over much of Tanzania and the
  neighboring areas of Mozambique and Malawi.