If I read the archived pressure/front maps right, in part: storms over Paris must have been caused by a cold front of a depression moving over the Baltic Sea; three days later, this and a previous cold front of this depression (over St. Petersburg by then) and that of another depression over Italy linked up over the Carpathian Basin, producing a very strong temperature gradient. (I remember from the no more archived temperature map that Western Hungary had 10°C at the same time Eastern Hungary had 28°C, with a sharp transition of at least 10°C right above the Danube.)

_{*Lunatic*, n.
One whose delusions are out of fashion.}