Sunday, a swath of Europe spread between the U.K and the Alps will get its warmest day of the year so far.
Temperatures will reach 18 to 24 degrees C (65 to 75 degrees F), which would imply readings at least 6 to 10 degrees C (11 to 18 degrees F) above normal.
The marked warming will follow on the heels of unusual March and early April cold across the U.K., Germany, France, Switzerland and the Low Countries.
London will warm to 20 degrees C (68 F), which would easily top the high of 16 degrees C (61 F) reached on March 5.
In Germany, Frankfurt should hit 22 degrees C (72 F), well above the previous high of 17 degrees C (63 F) that was set on March 8.
Paris, in also reaching 22 degrees C, would best its previous 2013 high by at least 6 degrees C.
Other areas with respect to normal will reach 18 to 24 degrees C (65 to 75 degrees F), which would imply readings at least 6 to 10 degrees C (11 to 18 degrees F) above normal.
While cooling will begin Monday in the U.K. and western France, areas farther east will warm even further as the heart of May-like warm spreads into central Europe.
A powerful Atlantic storm, spinning west of the British Archipelago Saturday and Sunday, will be the warming agent. Mild air will sweep northward ahead of the storm's trailing cold front, driving out the last of the late wintry chill left over from the frosty month of March.
Unusual cold and snow were widespread in Europe during mid to late March, and much of Europe was still much colder than usual for first nine days in April.
The plum rains are known as "meiyu" in China, the "baiyu" or "tsuyu" in Japan, and the "jangma" in the Koreas. The heart of the plum rain season stretches from early June to mid-July, with a tendency to shift south to north across the affected area.
In the wake of the mid-June cloudbursts, most of Pakistan to northwestern India last week saw a return to dry, hot weather typical of the weeks leading up to the Monsoon onset. It was as if the Monsoon withdrew to its "normal" position for the latter half of June.
The 38.5 degree C (101 degrees F) reading Tuesday in Ajaccio, Corsica, may have been tops in Europe.
Monsoon Onset was June 13th, 2013, in Delhi, almost two weeks earlier than average. The June 15th onset at Karachi and Islamabad was more like three week ahead of schedule.
In Pakistan, hit-or-miss downpours missed the Sindh capital, Karachi. One did hit Pad Idan, where it left 60 mm of rain Wednesday. This was more than 20 times greater than the normal June rainfall.
It is still possible that this scenario is over wrought as to the intensity and spread of rain in Pakistan and northwestern India. However, it is the hunch of the present forecaster that some very unusual weather is going to unfold in the Subcontinent during the next week!