Thread by @althecat

The forecast path of Extratropical Cyclone Sam is unusual to say the least. The storm is expected to reach as far north as Iceland. And will continue to impact European Weather significantly for several more days.

Here is a 120 hour forecast for the north Atlantic where you can see how the storm continues northwards.

Here's another view of the same model, @NOAA's GFS which places it in larger context.

This forecast animation also from the GFS model data takes us forward for 16 days, and it is apparent that tropical systems impacts on Europe persist for some time yet.

Finally, to help understand why these weather impacts are causing significant issues here is 16 day forecast of the North Western Hemisphere jet-streams, which remain spectacularly complicated and unsually disorderly.

This additional thread posted earlier shows us the consequences of this complexity, with live data over the past 24 hours in Europe.

https://twitter.com/althecat/status/1445325139709763586?s=20

Within the atmospheric column there are multiple different atmospheric rivers, moving in different directions at different altitudes. The jet-streams, which are 10-18kms high are the most important as they transport the most water, and do so at high speed over long distances.