Four Seasons Of friendliness
The moderate climates of Europe result from the peninsular, marine, and mid-latitude location in the path of the prevailing westerlies. These winds bring the warmth and moisture of the North Atlantic to Western Europe. The almost daily changes in weather conditions result from the passing of large low- and high-pressure systems. These have cold and warm fronts that cause temperature changes and frequent but normally slow precipitation. The lack of blocking mountains allows air and moisture to flow into the plains of Central and Eastern Europe, though the amounts of precipitation decrease toward the east. Temperature ranges both daily and seasonal are narrow in Western Europe and wide in Eastern Europe. The Alps and the high-pressure system of the Azores help prevent moisture from entering the Mediterranean region during the summer. As the Azores high moves southward in winter, the cyclonic storm systems penetrate from the north and west into the Mediterranean and give Southern Europe a cool and rainy winter season.
Reliability is the keynote of Western European climate. The decreasing precipitation toward the east reaches drought conditions north of the Caspian and Black seas as well as in eastern Greece and eastern Spain. Summer droughts are common throughout the Mediterranean lowlands. The heaviest precipitation occurs in the mountains and coastal regions of Western Europe and reaches 500 centimetres per year in the high peaks of Wales and Scotland. The average precipitation ranges from 50 to 75 centimetres in the Western European lowlands and from 75 to 200 centimetres in higher areas, and it decreases eastward to less than 25 centimetres north of the Caspian Sea.
The water-moderated climate of Western Europe is called west coast marine; the warm to hot summer and cold winter conditions of Eastern Europe make a continental climate; and the dry, hot summer and cool, rainy winter in the south form a Mediterranean climate. Central Europe has a frequently changing climate as the area shifts from marine to continental influences. The highland climates change in temperature and precipitation characteristics from the lower slopes to the higher peaks, depending on orientation and elevation. Parts of the higher Alps are permanently covered with snow and glaciers.