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These represent the effect of the vertical component of negative wind pressures on roof elements, that is, directed away from the roof.
Uplift loads are not generated by Sizer, you must calculate these pressures, then distribute them to the wall lines by tributary area or other methods manually.
They are usually entered on the upper level only, but can be entered on any level. They can be entered for both wind directions, because the value of wind pressures on a sloping roof is dependent on whether the load is windward or leeward to the roof.
If the building includes devices that cause the roof to detach under high wind loading, then these loads should not be added.
These loads are entered unfactored; the same load combination factor as for wind shear loads is applied when hold-down and compression forces are made.