Weather Underground Forecast for Saturday, May 18, 2013.

A broad area of low pressure will create more active weather for much of Europe on Saturday. The system will continue spinning over western Europe, pulling more moisture and energy in from the Bay of Biscay and North Atlantic Ocean. This will support widespread shower activity across Spain, Portugal, and France, with isolated thunderstorm activity developing over southern France and into northern Italy. Some of these storms will make their way into Switzerland late Saturday night. Expect rain and thunderstorm warnings to remain in effect for most of western Europe and the Iberian Peninsula. Barcelona will be cloudy and breezy with a chance of rain and highs in the mid-60s(F)/ upper teens(C), while Paris will be overcast and rainy with highs near 60(F)/ 16(C). Rome will be east of this activity with partly cloudy skies and dry conditions with highs in the upper 70s(F)/ mid-20s(C).

To the north, two troughs of low pressure will extend away from this larger low pressure system. One trough of low pressure will move northeastward through Germany and Poland, reaching into the Baltic Sea by Saturday evening. At the same time, another system will move northeastward over the British Isles. These systems will trigger more widespread showers and thunderstorms for these areas throughout the day. London will be overcast but dry with highs in the mid-60s(F)/ upper teens(C), while Munich will be partly cloudy with a chance of showers in the afternoon and evening with highs near 70(F)/ 21(C).