shelf, rainbow, 49th thunderstorm day

One week later, on Sunday September 26th, the situation again became interesting. With a strong southerly flow, moist warm air was rapidly advected northward over eastern Europe. Even without notable sunshine the temperature easily reached 24 C in the early afternoon.
A coldfront was approaching from the west-southwest, as can be seen on this weathermap:


Surface analyses for 26 september 2010, 00 UTC.













And yes, in the late afternoon this storm came in from the south:





















When the rain and gusts were over, an extremely bright rainbow (category 5) was visible in easterly direction. For me it was the brightest rainbow in years.
These are two images of the rainbow (no photoshop here):
































Till so far, NO thunder was observed with this "storm". However, when it moved further east, it activated enormously and I observed thunder & lightning at the back of the storm, so I could write the 49th thunderstorm day of 2010 in my observation-book.
A nice squall line with embedded discete cells at the front and trailing stratiform precipitation, developed over the eastern Carpathian mountains in the course of the evening: