Weekly Africa Weather Hazards Assessment Explanation

September 19-25, 2002

1) Precipitation increased in intensity and coverage throughout much
of Senegal and southern Mauritania during the pervious week, as
widespread accumulations of near 30 mm were common.  Locally, heavier
rainfall with totals greater than 50 mm were recorded in the region.
Seasonal rainfall totals continue to be the lowest in at least fifty
years in much of the area.  Little rain is forecast for the next week,
although coastal areas of Senegal may receive greater accumulations.

2) A low pressure system currently located northwest of Morocco is 
forecast to move to the east during the next week, bringing the
possibility of heavy rains and strong winds to parts of northern Algeria
and northern Tunisia.  Latest meteorological forecast models are 
predicting the storms to begin on or around September 21-22 and move
quickly out of the area, but not before creating some local flooding
problems in the region.

3) Parts of northern Ethiopia near the eastern Eritrea border received
locally heavy rainfall during the past week, with totals reaching 125 mm.
Other than this unusually heavy rainfall, much of the region highlited
in the hazard bulletin received little precipitation.  Rainfall models
are predicting light rainfall throughout the area during the next week
as the focus for heavier amounts shifts southward.  Although substantial
seasonal rainfall has occurred in much of northern Ethiopia, areas of
dryness continue to remain, and little additional rainfall is expected
throughout the next months.

4) Dryness extending through southwestern Ethiopia continues to exist,
although moderate rainfall was seen locally during last week.  Locally
moderate rainfall is again forecast for the next week with totals as
high as 20-40 mm.

5) A semi-organized weather system is currently located in the central-
western Indian Ocean and is forecast to move westward during the next
seven days.  Models are split in forecasting the speed of this low
pressure area, but rainfall should reach the coast somewhere between
southern Somalia and northern Tanzania around September 21-24.
A fluctuation in north-south position as the rainfall moves to the west
will change the intensity of precipitation that may fall over coastal
areas.  Any moderately heavy rainfall that occurs over the area will
cause additional local flooding problems.

6)  Little rainfall was recorded during the previous week in the drought
affected areas of southern Zimbabwe, southwestern Mozambique, northeastern 
South Africa, and eastern Botswana.  Although little rainfall occurred,
a comparison between 2001-2002 seasonal rainfall and normal rainfall in 
eastern Botswana indicates that the area may not be as hydrologically
dry as previously noted.  Rainfall time series data show the area 
substantially above drought limits, thus parts of the region have been
dropped from the hazard.

7) Heavy rains up to 150 mm may fall over saturated soils of eastern
Nigeria and western Cameroon during September 19-25 and could bring local
flooding to the region.  


Timothy B Love