Created a new album with altitude and GS both in the same graphs.
KGL9268 - Altitude and GS - Album on Imgur
The data does seem to be rather consistent, since there are no outliers before the 250th second.
What is interesting is that GS drops to below 100kts on both stations 2132 and 2593 (2614 stops receiving after second 261) drop along with the altitude
D.