Regional Climate Summaries: US Highlights - Temperature and Precipitation
Regional Climate Summaries: African Sahel
Table of Contents
Europe recorded above-normal temperatures during all months of 1994, except February and October. In many places, the year ranked as the third warmest on record (after 1989 and 1990), and in some parts of southern and central Europe, it was the warmest since the beginning of observations more than 200 years ago. For example, in Vienna, Austria (Fig. 4.20) mean annual temperatures during 1994 were more than 2C above normal, exceeding the previous largest anomaly of 1.8C set in 1992 and setting a new all-time record dating back to 1775.
The extreme warmth was particularly pronounced over Europe during the second half of the year (July-December), when temperatures averaged 1.5-2C above normal throughout central Europe (Fig. 4.21, bottom), and more than 1C above normal over most of the remainder of the continent, including much of Scandinavia. In central Europe, these anomalies exceeded the 98th percentile (Fig. 4.21, top), while they generally exceeded the 90th percentile throughout the rest of Europe.
Between July and December, two particularly extreme warm periods were observed. From late June through early August, one of the hottest spells ever to afflict central Europe developed (Figs. 4.22a-d) in association with the establishment of a major blocking anticyclone throughout the region (Fig. 4.23). During this period, the largest temperature anomalies (3-6C above normal) were observed in Germany, where new all-time record maxima were set at several locations. At Hamburg, Germany a time series of July temperature anomalies beginning in 1850 (Fig. 4.24) indicates that July 1994 was the warmest on record, exceeding the previous record anomaly of +3.0C by more than 2.2C. A sample of extreme daily temperatures reported during the period were: Murcia, Spain (46.1C) on 4 July; Lycksele, Sweden (36.7C) on 7 July; Budapest, Hungary (36.3C) on 30 July; Berlin, Germany (38.1C) on 1 August; Virton, Belgium (38.9C) on 3 August; Volkel, Netherlands (36.1C) on 4 August; and Paris, France (36.1C) on 4 August.
During September (Figs. 4.22e, f), much of western and central Europe reported near-normal conditions, as the area of near-record warmth shifted well eastward into eastern Europe and southwestern Russia. In October (Figs. 4.25a, b), the area of above-normal temperatures shifted farther southeastward and became centered over the eastern Mediterranean Sea. Farther north, much of Europe recorded near-normal temperatures during the month, while extreme northern Europe and western Scandinavia observed below-normal temperatures (1-2C below normal).
Record or near-record warmth then returned to western Europe in November and December (Figs. 4.25c-f). These conditions were associated with a large-amplitude and persistent wave pattern at jet stream level throughout the North Atlantic and European sectors (Fig. 4.26). The key features of this pattern included below-normal heights over the high latitudes of the North Atlantic, above-normal heights throughout Europe and southern Scandinavia, and below-normal heights extending northward from the eastern Mediterranean Sea to Siberia. This circulation reflected above-normal pressure throughout Europe, and abnormally strong southwesterly flow throughout the western portion of the continent. Accompanying this circulation, surface temperatures averaged 3-5C above normal over large portions of Great Britain and northwestern Europe. In central England, November 1994 was the warmest November in the 336-year record, by more than 0.5C, and it exceeded the November 1993 temperature by more than 5C (Fig. 4.27, which only shows the more reliable data since 1772). During December, temperatures throughout western Europe averaged 2-3C above normal and remained above the 80th percentile (Fig. 4.25e, f).
Regional Climate Summaries: US Highlights - Temperature and Precipitation
Regional Climate Summaries: African Sahel
Table of Contents
