Deadly flooding has inundated parts of northern Europe this week, prompting the closure of roads, businesses and museums and leaving people wondering when the dirty water will finally recede.

The situation is particularly bad along the Seine River in Paris, where a French river-monitoring group has issued an orange alert for river flooding. This means large river overflow is possible, which could have a significant impact on surrounding areas and the safety of nearby residents.

The Seine is expected to crest around 21 feet Friday afternoon — the highest crest since 1955, the BBC reports. Water levels along the Loing, a tributary of the Seine, have already toppled record crests from the major flood event in 1910.

The statute of a Zouave soldier on the Pont de l’Alma has served as a historical benchmark for flooding along the Seine since the bridge was completed in 1856. When the water reaches the soldier’s thighs, the river ceases to be navigable. It had nearly reached the soldier’s waist Friday. During the great flood of 1910, the Seine climbed to the soldier’s shoulders.

Even though the water levels in Paris haven’t risen to 1910 levels, it has risen far enough to threaten some of the world’s most valuable art. The Post’s James McAuley reports from Paris that Thursday night, the Louvre began to move 250,000 works of art from harm’s way — mainly those in basement storage:

Exempting museum renovations, the last time as many works of art were transported as quickly and as frantically may have been the years leading up to the Nazi invasion of France in 1940, when the museum leadership sent the collection’s masterpieces to a slew of safe locations across France.
The Mona Lisa, the iconic centerpiece of the museum’s collection, is already displayed on a higher floor, out of harm’s way.

So why is the flooding so bad? It started when an upper-level low become cut off from the jet stream, right under an omega block.

An omega block is a jet stream pattern where a ridge of high pressure builds north, surrounded by two areas of low pressure. It forces warm air farther and farther north under the ridge. A positive feedback sets up that can be hard to break — the high temperatures strengthen the ridge, the ridge leads to more warmth, and so on. This pattern can stick around for a long time. Some of Europe’s longest and deadliest heat waves have been caused by an omega block that refused to budge.

Over the past week, a similar situation took hold over the continent with one critical difference: a low pressure system developed underneath the ridge, cut off from the jet stream. If troughs and ridges don’t flow freely across the hemisphere — as in the case of an omega block — there’s nothing to move that low pressure along.

So it rains. And rains. And rains.

The Weather Channel’s Tom Moore cataloged the exceptional impacts in France and Germany:

  • In Paris, lightning injured 11 people in a park, most of them children
  • An entire day’s play at the French Open tennis tournament was washed away by rain
  • Six weeks worth of rain — over 5 inches — fell in 24 hours near the France-Belgium border in one week
  • In Germany, flooding has resulted in at least four deaths
  • Train traffic in Germany between Bremen and Hanover was briefly halted after a mudslide

River flooding in France continues as all that water flows to the North Atlantic. Though the weather has returned to normal (somewhat), the effects will continue downstream for another week.