IRI Climate Digest April
March Global Climate Summary
Climatological Background In March, the sun crosses the
equator (the Equinox) and begins its migration into the Northern Hemisphere.
It is the transition from winter to spring in the Northern Hemisphere,
when temperatures begin to increase and storm tracks move northward. In
the Southern Hemisphere summer is ending and the monsoon rains are retreating
Monthly Mean Temperature (1961-1990), data from the Climate Research
Unit, University of East Anglia
Monthly Mean Precipitation (1961-1990), data from the Climate Research
Unit, University of East Anglia
Temperatures Over Land
Above average temperatures continued across a broad region extending
from northern Africa northward to southern Europe and eastward to the Pacific
coast of China. Much of Canada saw another unusually mild month while
temperatures were lower across southern Australia easing unusually warm
conditions which had prevailed since January.
Europe: Above average temperatures persisted across all
of southern Europe.
Temperature Difference from the 1961-1990 mean, with
data from NCEP Climate Prediction Center, CAMS.
Asia: Unusually warm conditions extended from Turkey and
the Ukraine eastward to China.
Africa: The region of above average temperatures seen
along coastal areas in western and northern Africa over the past few months
continued in March and expanded to include much of the interior sections
of north Africa.
Australia: Temperatures were close to average across southern
Australia, easing unusually warm conditions that had prevailed for the
past few months. Much of Western Australia saw below average temperatures.
North America: Much of Canada was unusually warm during
March with many northern and western areas having seen above average temperatures
Heavy rains eased somewhat in southern Africa. Unusually dry conditions
persisted over parts of western Asia and southeastern Brazil.
Africa: Rainfall eased somewhat from the previous month
but continued above average across northern Mozambique, Zambia, Zimbabwe
and Malawi. Rainfall was mixed over the Greater Horn with eastern
sections of Kenya and Ethiopia being somewhat below average with conditions
slightly wetter than average across central and western areas. Much
of Tanzania was drier than usual for the month.
Precipitation Difference from 1961-1990 mean, with
data from NCEP Climate Prediction Center, CAMS-OPI.
South America: Below average rainfall continued across
southeastern Brazil. Coastal sections of Peru and Ecuador saw above average
rainfall as did much of Uruguay and northeastern Argentina.
North America: Beneficial rainfall fell across the southeastern
United States while along the west coast, unusually dry conditions prevailed.
Europe: Unusually heavy rainfall was observed over much
of the Iberian Peninsula.
Asia: Precipitation continued below average across Afghanistan,
Pakistan and Iran.
Australia: North-central regions of Western Australia
saw unusually heavy rainfall as did coastal areas in northern New South
Tropics: The modest La Niña conditions in the central
Pacific weakened somewhat over the past month while slightly above average
sea surface temperatures (SSTs) have developed in eastern areas, especially
along the South American coast. Current statistical and computer
numerical models predict an end to the La Niña conditions over the
next two months with the development of slightly above average temperatures
in the equatorial Pacific by the end of the year.
Midlatitudes: Above average SSTs in the North Atlantic
have weakened from last month with little change elsewhere. Warmer
than average SSTs persist across the central South Atlantic and South Pacific
basins as well as the southern Indian Ocean. Colder than average
SSTs continue across the central North Pacific.
Monthly Sea Surface Temperature Difference from the 1950-1979 mean,
with data from the Environmental Modeling Center, NCEP/NOAA.