Temperatures were warm across the northern half of the African continent during April. Warm anomalies greater than 4 C were observed over interior sections of western Africa. This region has also experienced a lack of precipitation over the past several months leading to drought conditions. Temperatures anomalies were mixed across the Great Rift Valley in east Africa but drought conditions reportedly affected 8 -10 million people in the Horn of Africa. Some of the coolest anomalies on the globe were observed over the southern third of Africa across Botswana, Zimbabwe and South Africa where temperatures were more that 4-6 C below average. This area had persistent precipitation, cloudiness and periodic flooding during the month. More information about these conditions is available at NCDC's Climate Watch.

European Temperature Product

Europe is a study in contrast this month. A westerly flow off the Atlantic kept western regions unsettled with stormy periods and below average temperatures. To the east across central and eastern Europe and the Former Soviet Union (FSU), a ridge of high pressure kept the region unusually warm. Temperatures were greater that 4 C above average in a large area from the Czech Republic eastward to the Black and Caspian seas.

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Temperature Anomalies across Asia

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Warm conditions earlier this spring persisted across most of the region during April. The warmest regions were from the Middle East across interior portions of the Indian subcontinent. Interior areas of India and Pakistan experience their hottest weather climatologically in April and May prior to the onset of the "monsoon" and this region was more that 4 C above the 1992-2000 average for the month. For more information on the "monsoon" cycle click here . Cooler than average temperatures were observed over southeast China and parts of southeast Asia.

Temperature Anomalies across the United States

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A cooler northwesterly flow of air across the eastern United States kept much of this region near or below average this month. This was the first month since October 1999 that the Southeast Region had below average temperatures. Extreme interannual temperature variability has characterized the April monthly mean temperature in the Southeast throughout the period of record. See the graph for a time series temperature analysis for this region. Elsewhere across North America, warmer than average temperatures were noted from west Texas northward into the southern Canadian Rockies.

Snow Cover Anomalies across The United States

The snow cover anomaly map reflects the general upper-level circulation and surface temperature pattern across the continent during the month. The dominant ridge over the western half of the country prevented the normal accumulation of snowfall for the central and northern Rockies as well as parts of the Pacific Northwest. Most of the northeastern U.S. had greater than normal precipitation and normal to above normal temperatures, therefore little snowfall occurred in the region.

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Time Series Precipitation Departure Plot for Hungary.

An unusual global extreme this month was flooding in Hungary. Due to heavy precipitation during the late winter and early spring and warmer than normal temperatures along with rapid snowmelt in the mountains, flooding and landslides have hit central and eastern Hungary for the second year in a row. The time series plot to the right show precipitation anomalies above the average. The graph is for the March-April period and shows that this year (March-April) 2000, was the wettest such two month period in the last 50 years.

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Europe/Asian Snow Cover Anomalies

Snow cover was well below the 1992-2000 average across a large part of the Former Soviet Union (FSU) eastward into central and northern Siberia. The combination of warm temperatures and below average precipitation led to below average observed snowcover. The animation shows the lack of snow cover around the Ural mountains during the beginning of the month with decreasing snowcover along the Russian-Kazakhstan-Mongolian border areas by month's end.

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References:

Basist, A., N.C. Grody, T.C. Peterson and C.N. Williams, 1998: Using the Special Sensor Microwave/Imager to Monitor Land Surface Temperatures, Wetness, and Snow Cover. Journal of Applied Meteorology, 37, 888-911.

For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:

Climate Services Division
NOAA/National Climatic Data Center
151 Patton Avenue, Room 120
Asheville, NC 28801-5001
fax: 828-271-4876
phone: 828-271-4800
email: ncdc.orders@noaa.gov

For more information, refer also to ...
SSMI Derived Products
Global Historical Climatology Network (GHCN)
The Blended GHCN - SSM/I Product
The Global Temperature Anomalies

Tom Ross
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4499
email: tom.ross@noaa.gov

Alan Basist
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4107
email: alan.basist@noaa.gov

Mike Changery
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4750
email: mchangry@ncdc.noaa.gov

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