So, this updates this story from two days ago.
At that time, there was only one geoconfirmed Russian spotting on the map either on or approaching the path of the advance in southern Avdiivka (red arrow). Now, as you can see here (red dots), there are about 15. That means two things. First, Russia is strongly reinforcing that advance and pushing it forward (red dots IN FRONT of the red arrow). The second thing it means is that Ukraine is responding to the advance. The geoconfirmed spottings are drone attacks. However, it will take more than drones to push these bad guys out. Undoubtedly the fighting is pretty fierce down there.
Next, the key here is a place called ZENIT (see map). Zenit is an ex-Russian air force installation that housed air defense assets for the protection of the Donesk Airport which is just over 2 km away to the SW. It’s a fortified bunker-like position that has been occupied by the Ukrainian army since at least the 2014 Russian illegal occupation of Donetsk. That means it’s a really tough nut to crack and Russia has been unable to crack it.
On the first map above, the blue circle is essentially machinegun range (1000 meters) from the center of this “fort.” It is not coincidence that the Russian front line (green) stops on or about that threshold. All the buildings have long since been destroyed, but the Ukrainians are dug in deep.
The problem is pretty obvious. This Russian attack (red arrow) flanks and bypasses Zenit and makes it intenable if it continues even a very short way. To illustrate, the yellow straight line on the first map shows a 2500 meter shot west from the T-05-05 highway. The bottom bit of the map shows the elevation profile of that line.
PANCAKE FLAT!
And slightly downhill. Attempting to drive anything through there from north to south will be suicide not be pleasant. If cut off from resupply, this linchpin of the southern defense of Avdiivka can’t stand for long. There is enough cover and/or concealment to manpack in supplies, but this has obvious limitations. Furthermore. the route Ukraine uses to supply Zenit is only about 800 meters along that yellow line, so it will be within machinegun range. Finally, at a point about 500 meters south of the yellow line, this resupply route splits and also goes west to supply the Ukrainian troops defending north of Opytne, so that position is also at risk.
Now look at the bigger picture.
If Zenit and the Opytne line fall, the entire western flank of Avdiivka is at risk. There are treelines/wind breaks, but they cannot be as tough nuts to crack as an underground bunker-like position that has been fortified for the better part fo a decade. Even if the Russians only go a couple of km, a good bit of the main supply route, the T-05-05 highway, is open to direct fire because much of that area is flat, too. That would make supplying southern Avdiivka difficult.
Again, none of this is preordained. These are risks and threats.