Synchronize And Combine Timetable Columns in MATLAB?

Question

I'm trying to add new datapoints to an existing timetable in MATLAB. The problem I'm having is that all the join commands either don't work because they require the tables to share a dimension, or add the data that I want to put into an existing column as a new column with a different name instead.

Here's an example to illustrate what I mean:

load outdoors
TT1 = head(outdoors); TT1.PressureHg = [];
TT2 = TT1; TT2.TemperatureF = [];
TT2.Time = TT2.Time + hours(4);
synchronize(TT1, TT2) %this doesn't do it...
outerjoin(TT1, TT2, "MergeKeys", 1) %nor does this.

Is there a way to get all the Humidity data into one column?