Here in the Houten, the sky was clear this morning, with a beautiful view of the moon and Venus in the sky. Rain is predicted later in the day, looks like the WFS 1 is moving eastwards. Here is a Google Earth Image of a balloon trajectory forecast (0600UTC) using locations of De Bilt. The cloud information is for 0700 UTC, provided by Google Earth. The WFS 1 is in the bottom left corner.
Regarding the SATREP for today. There is a WFS identified by SATREP over Belgium (1) and one over Finland (2). Both have a CF in CA along the vertical element of the letter T which I described in a previous post. WFS 1 is a T rotated from vertical to the right. WFS 2 is more or less straight. Actually, this T in the isotachs looks more like a pickaxe.
The frustrating thing about isotachs is that the direction of motion is not obvious to me. The wind direction from the local station in Houten is coming from the S (0830 UTC). But midnight it was more W-SW, which corresonds with the midnight radiosondes. Belgium, Netherlands and North France all have the wind coming from 270 degrees, i.e. from the west (UTC 0000, 6 hours earlier than the SATREP report I am looking at). There is a strong gradient in the isotachs (oriented North south) at the edge of the WFS1. The whole edge is moving east (Check EUMETSAT loops).